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A Twist to Tuesday’s Severe Weather: Tornadoes Missing

By: Bob Henson 5:15 PM GMT on April 27, 2016

Tornado chasers scanned the skies fruitlessly on Tuesday, while residents of the Southern Plains breathed huge sighs of relief, as a bumper crop of severe thunderstorms produced buckets of large hail and high wind while spinning up only a handful of twisters. By mid-morning Wednesday, NOAA’s Storm Prediction Center (SPC) had received only five tornado reports: two in Texas, and one each in Kansas, Missouri, and Indiana. All of these tornadoes were relatively minor, with no serious damage or injury reported. High wind and large hail were far more plentiful, with more than 200 reports of each. Most of the hail was 1” to 2” in diameter, but several reports of 3” hail (larger than baseball size) came in from Marshall County in northeast Kansas. Winds gusted to 87 mph around 10:30 pm as a fierce squall line tore through Copan, Oklahoma, northeast of Tulsa.


Figure 1. Preliminary reports of severe weather received by the NOAA/NWS Storm Prediction Center for the period from 12Z (8:00 am EDT) Thursday, April 26, 2016, through 12Z Wednesday. Image credit: NOAA/SPC.


Figure 2. Lightning strikes along Interstate 70 near Junction City, Kansas, late Tuesday, April 26, 2016. Image credit: AP Photo/Orlin Wagner.


Figure 3. Susan Goodwyn holds large hail deposited by thunderstorms that swept through Wichita, KS, on Tuesday afternoon, April 26, 2016. Image credit: Susan Goodwyn/SMGPhotos via AP.


What happened to the tornadoes?
Tuesday’s outcome was far better than many residents had feared that morning, when forecasters were calling for widespread severe storms and the potential for strong tornadoes. This shortfall in tornado production wasn’t a total surprise. As we noted in Tuesday’s post, upper-level winds were not ideal for a major tornado outbreak, but it seemed plausible that adequate wind shear would accompany the extreme instability in at least a few locations that would be difficult to pinpoint well in advance. Along these lines, the large tornado watch issued for parts of Texas and Oklahoma was a PDS watch--meaning a “particularly dangerous situation,” with “several tornadoes and a few intense tornadoes likely.”

As it turned out, the upper-level winds were far from optimal during the afternoon, and by the time wind shear had improved, a squall line had formed, making it hard for any isolated supercells to develop and rotate. Thus, it was a day with high-end potential for strong tornadoes, but relatively low confidence as to how many there might be. NOAA’s midday outlook on Tuesday bore this out, with relatively low probabilities for tornadoes (maximum 10%) but much higher odds for severe hail (maximum 45%).

SPC had noted Tuesday’s potential for severe weather, including tornadoes, as far back as last Thursday, April 20. So was the forecast a bust? That depends on your perspective, and how you interpret forecaster guidance. For all time periods beyond 24 hours, the SPC convective outlooks (explained here) indicate only two things:

--the categorical risk of severe weather (from marginal to high)
--the numerical odds of getting any type of severe weather within 25 miles of any spot on the map

“Severe weather” means any or all of these:
--a tornado
--winds of at least 50 knots (58 mph), or lesser winds that inflict damage
--hail at least 1” in diameter

For Days 1, 2, and 3, the outlooks also include a crosshatched area where severe weather might be “significant”, meaning:

--a tornado inflicting at least EF2 damage
--winds of at least 65 knots (75 mph)
--hail at least 2” in diameter

With these definitions in hand, we can see that Tuesday’s outlook was far from a total bust. Figure 3 (below) shows how the outlooks issued at various lead times stacked up against the final outcome (top row, against the midday outlook issued at 12:30 pm EST Tuesday). The tornado count was undeniably low--and two of the day’s five reports were entirely outside the probabilistic risk area, associated with a bow echo across the Midwest--yet the tornado odds were relatively low to begin with, maxing out at just 10%. The hail outlook appears to verify quite well over the Southern Plains, given that about half of the 45% max-threat area (purple) experienced large hail within 25 miles. The Ohio Valley bow echo did produce more large hail than expected.


Figure 3. The progression of guidance issued by the NOAA/NWS Storm Prediction Center leading up to Tuesday, April 26, 2016. At bottom left of each panel is the lead time: Day 7 corresponds to a forecast issued six days prior (in this case, Wednesday, April 20). Day 4-8 outlooks include only the probability of any type of severe weather within 25 square miles of any point. Days 3, 2, and 1 include subjective categorization of the total risk (marginal, slight, enhanced, moderate, or high). Along the top are the Day 1 outlooks issued at 1630Z (12:30 pm EDT) Tuesday for the probability of any severe weather (left), tornadoes (center), and severe hail (right). Crosshatching indicates the forecasted possibility of significant tornadoes (EF2 or stronger) or very large hail (at least 2” in diameter). Symbols on the Day 1 outlooks along the top show actual reports from Tuesday for each category. Image credit: NOAA/NWS/SPC, courtesy James Correia (OU/CIMMS).

The question of lead time
The week-long build-up to Tuesday’s severe weather led to some soul-searching in the meteorological community: what is the value, and potential downside, of giving people five or six days’ notice that an outbreak may occur? An AP analysis by Seth Borenstein and Kelly Kissel, published on Saturday, covers the issues well. WXGeeks host and WU contributing blogger Marshall Shepherd (University of Georgia) also explored the topic thoughtfully in a Forbes essay last Thursday. (Shepherd also has some great perspective on yesterday's presumed forecast bust.]

There is some evidence that specific tornado warnings could be counterproductive if issued well in advance (such as two hours), as people may put themselves at increased risk rather than taking immediate shelter. More general outlooks, issued days ahead of time, may be a different matter. Research is still scant in this area, but long-lead outlooks could give emergency managers and response agencies extra time to raise awareness and assemble resources. Veteran atmospheric researchers such as Lance Bosart (University at Albany, State University of New York) point to the scientific accomplishments that have made such extended outlooks possible. In an email to colleagues, Bosart said:

“The achievement of being able to recognize the potential that a high-impact severe weather event will occur and where it will likely occur a week in advance is testimony to how far numerical weather prediction has advanced, how well new convection-allowing ensemble models have been integrated into the forecast process, how much probabilistic thinking has been incorporated into forecasts of high-impact severe weather events, and how well the dedicated professionals at the SPC have been able to take full advantage of these advances to produce operationally informative and useful guidance well in advance of expected severe weather outbreaks.”


Figure 4. As of mid-morning Wednesday, SPC’s convective outlooks show a slight risk of severe weather on each of Days 1, 2, and 3 (Wednesday through Friday, April 27-29, 2016).

It’s not over yet: more severe weather in the cards
With upper-level troughiness persisting in the West, and plenty of low-level moisture at hand, severe storms are a continuing possibility into this weekend. Wednesday’s threat straddles the Mississippi Valley from eastern Missouri to southern Louisiana. The day should yield mostly garden-variety severe weather, with the tornado risk quite low. More storms are possible over Texas and Oklahoma late Thursday night, with activity building on Friday as the upper-level low recharges and a warm front pushes north. Moderately strong wind shear and very high instability suggest the potential for a tornado threat worth monitoring on Friday across parts of Oklahoma and north Texas. The active pattern shows signs of continuing off and on as we roll into the first week of May and the peak of U.S. tornado season.

Bob Henson


Extreme Weather Tornado Severe Weather

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments


 The rain chances I mentioned yesterday have pretty much vanished. Guess I'll put that sandbag away...
Thanks for the new Post, Mr. Henson...
Reposted from the prior blog

I think it's hard for people to realize the scale impacts of global warming. We're a water planet, folks, and our average temperature in vast areas is near the boundary where water freezes and melts! Remember, physics just doesn't care about our ideologies, beliefs, opinions or preferences. Physics just is.
http://www.theguardian.com/environment/2016/apr/0 9/melting-ice-sheets-changing-the-way-the-earth-wo bbles-on-its-axis-says-nasa

Global warming is changing the way the Earth wobbles on its polar axis, a new Nasa study has found.

Melting ice sheets, especially in Greenland, are changing the distribution of weight on Earth. And that has caused both the North Pole and the wobble, which is called polar motion, to change course, according to a study published on Friday in the journal Science Advances.

Original Paper is published here

http://advances.sciencemag.org/content/2/4/e15016 93

Abstract
Earth's spin axis has been wandering along the Greenwich meridian since about 2000, representing a 75degree eastward shift from its long-term drift direction. The past 115 years have seen unequivocal evidence for a quasi-decadal periodicity, and these motions persist throughout the recent record of pole position, in spite of the new drift direction. We analyze space geodetic and satellite gravimetric data for the period 2003-2015 to show that all of the main features of polar motion are explained by global-scale continent-ocean mass transport. The changes in terrestrial water storage (TWS) and global cryosphere together explain nearly the entire amplitude and mean directional shift (within 5.9- 7.6) of the observed motion. We also find that the TWS variability fully explains the decadal-like changes in polar motion observed during the study period, thus offering a clue to resolving the long-standing quest for determining the origins of decadal oscillations. This newly discovered link between polar motion and global-scale TWS variability has broad implications for the study of past and future climate.
From the previous blog, another round of storms forecast for Friday and Saturday.

re-posted from previous blog:

Quoting 214. calkevin77:



That stinks. If I recall, my grandparents in Wisconsin had issues with those bugs in the early 90s. I'm not sure how long it would take them to decimate the trees as some trees may be prone to dying off quicker based on their age, stability and trunk diameter. I'm pretty sure that they can destroy a forest in five to ten years similar to the bark beetles on the West Coast. You might want to call a local arborist and see if they can look at any remaining trees and ask if they have advice on what you can do to salvage them.


Thanks calkevin77. That rubicon has been passed. They haven't been only decimated... they're almost all dead! The county had a transport ban on all ash tree lumber and firewood, thinking that the emerald ash borer larvae would be spread around further if anyone carried the logs to new, uninfested sites. That transport ban was lifted in our DuPage county last year when it was determined that all the ash trees were already infested. These bugs first appeared here eight or nine years ago, and we had the trees treated each year to try to save them, but no such luck. The chemicals that they were using are the same ones that can cause bee colony collapse (neo-nicotinoids), so good riddance to those chemicals. Here, the bees have been in decline for years, but this year I think I see an increase in bees around the cherry trees. Or am I just imagining that?
By the way, near Detroit, Michigan, some 250 miles east, the ash trees all died ten years ago from the ash borer.
Follow up quote from the Guardian article gives an idea of the ice-water mass changes:

"Since 2003, Greenland has lost on average more than 272 trillion kilograms of ice a year, and that affects the way the Earth wobbles in a manner similar to a figure skater lifting one leg while spinning, said Nasa scientist Eirk Ivins, the study%u2019s co-author.

On top of that, West Antarctica loses 124 trillion kgs of ice and East Antarctica gains about 74 trillion kgs of ice yearly, helping tilt the wobble further, Ivins said."
Link

Bad round of storms in Houston area with at least one fatality in one of the Northwestern suburbs... Possible Tornado, NWS is checking it out. These were early morning storms that knocked out power and dropped some trees.
“This unprecedented event has now happened twice”: Massive seagrass die-off hits Florida Bay

EVERGLADES NATIONAL PARK, Florida — The shallow coastal waters of Florida Bay are famed for their crystal clear views of thick green seagrass – part of the largest stretch of these grasses in the world.

But since mid-2015, a massive 40,000-acre die off here has clouded waters and at times coated shores with floating dead grasses. The event, which has coincided with occasional fish kills, recalls a prior die-off from 1987 through the early 1990s, which spurred major momentum for the still incomplete task of Everglades restoration.


Link
Republican Climate Change Denial is Blinding Our Ability to Observe the Arctic

Denial.

It’s all-too-often what happens to the powerful when they are confronted with the consequences of their own bad actions. It can best be said that denial is blindness — the willful inability to open one’s eyes to the tough reality of the world. In literature, we can see denial in the tragic sin of hubris and in the metaphor of Oedipus the King gouging his own eyes out as a result of his failure to come to terms with the warnings of prophecy.

In the psychological sense, denial involves the inability to cope with reality such that a person will act in an irrational fashion to the point of generating fantasies that the object of said denial does not exist. Behaviorally, this results in an increasing degradation of a person’s ability to confront or cope with the object of denial — to the point of ardent, irrational, and possibly destructive outbursts when faced with it.


Link
Thanks for the new entry, Bob. I'm glad to learn that the furor of tornadoes wasn't so bad this time.

Meanwhile GW has abandoned central Europe and Germany for a while as it is still unpleasant cold and windy due to low Uta, filled with artic air. Fresh snow and deep frost in the Alps tonight. And I continue to groom my personal cold as well, so bye, but not without some hotter news to read:

Germany greens streets with €4,000 discount on every e-car
The Local (Germany) Published: 27 Apr 2016 14:17 GMT+02:00
Germany will subsidise electric car purchases to give a jolt to sluggish growth in the sector and help meet national climate goals with zero-emission mobility, the government said Wednesday. ...

Trafficking risk rises as villagers flee India's worst drought in decades
Source: Thomson Reuters Foundation - Wed, 27 Apr 2016 00:01 GMT
MUMBAI, April 27 (Thomson Reuters Foundation) - The worst drought in decades across several states in India is forcing tens of thousands of people to migrate from rural areas in search of water, food and jobs, increasing the risk that they may be trafficked or exploited, activists said.
About 330 million people, almost a quarter of the country's population, are now affected by drought, the government estimates. Destitute women, children and older family members left behind in the villages are most at risk of exploitation. ...


Venezuela state employees to work two-day week to save energy
Source: Reuters - Wed, 27 Apr 2016 00:43 GMT
CARACAS, April 26 (Reuters) - Venezuela's socialist government ordered public workers on Tuesday to work a two-day week as an energy-saving measure in the crisis-hit South American OPEC country.
President Nicolas Maduro had already given most of Venezuela's 2.8 million state employees Fridays off during April and May to cut down on electricity consumption.
"From tomorrow, for at least two weeks, we are going to have Wednesdays, Thursdays and Fridays as non-working days for the public sector," Maduro said on his weekly television program.
Drought has reduced water levels at Venezuela's main dam and hydroelectric plant in Guri to near-critical levels. The dam provides for about two-thirds of the nation's energy needs. ...


Citizen scientists collected rare ice data, confirm warming since industrial revolution
PhysOrg, April 26, 2016
In 1442, Shinto priests in Japan began keeping records of the freeze dates of a nearby lake, while in 1693 Finnish merchants started recording breakup dates on a local river. Together they create the oldest inland water ice records in human history and mark the first inklings of climate change, says a new report published today out of York University and the University of Wisconsin.
The researchers say the meticulous recordkeeping of these historical "citizen scientists" reveals increasing trends towards later ice-cover formation and earlier spring thaw since the start of the Industrial Revolution. ...


Scientists Show Connection Between Gas Flaring and Arctic Pollution
NASA, April 27, 2016
Thanks Bob, very good entry. I'd recommend people read this as a follow up as well, written by Angela Fritz.

Link

It definitely made me think. The forecast did verify yesterday, but people were obviously expecting more, and that indicates a failing by meteorologists on communicating the information. Weather geeks like us may have known that yesterday wasn't going to be a tornado outbreak, but we're the small minority, and in the end if expectations and reality are so far removed from each other for the public, we need to improve in that regard.
So far for the month of April I have picked up 11" of rain. With more on Saturday.
Quoting 10. MAweatherboy1:

Thanks Bob, very good entry. I'd recommend people read this as a follow up as well, written by Angela Fritz.

Link

It definitely made me think. The forecast did verify yesterday, but people were obviously expecting more, and that indicates a failing by meteorologists on communicating the information. Weather geeks like us may have known that yesterday wasn't going to be a tornado outbreak, but we're the small minority, and in the end if expectations and reality are so far removed from each other for the public, we need to improve in that regard.

It doesn't help when you have people like Mike Morgan releasing these kind of graphics:



Quoting 10. MAweatherboy1:

Thanks Bob, very good entry. I'd recommend people read this as a follow up as well, written by Angela Fritz.

Link

It definitely made me think. The forecast did verify yesterday, but people were obviously expecting more, and that indicates a failing by meteorologists on communicating the information. Weather geeks like us may have known that yesterday wasn't going to be a tornado outbreak, but we're the small minority, and in the end if expectations and reality are so far removed from each other for the public, we need to improve in that regard.
I agree with most of what you said--but, unfortunately, "Weather geeks like us"--or at least like some of us--were part of the problem, hyping the event for several days. Many here say that we should focus on severe weather outbreaks when they're underway, and I agree. But if we're going to be serious about the forum's value to news-hungry outsiders during severe events, then by the same token we have to be careful to not to fall into the hype trap ourselves.
Good news that the tornado threat was less than anticipated. It's always nice when that happens. My mother's family lives in Wichita, KS. In fact, as a young child I witnessed the Andover tornado as it began in Wichita. It was the first tornado I ever saw, and was likely a contributing factor in my being a weather geek now.

Now that I'm nicely settled in at my new place, life is calming down. I finally have the time to read not only the blog, but the comments also!

Having said that, I'm very happy that today is a reasonably "normal" day in Seattle. It's currently 54F, and cloudy at noon. Forecast high of 61F. Now that it's cooler, I'm able to really appreciate just how insanely hot last week was. It was 89F in Seattle last Monday. Warmer than LA and Pheonix. Needless to say, it shattered the previous record for the date, as well as hottest temperature for month of April. What is seriously stunning, is to note that the temperature anomaly of 31 degrees, broke the record for the single greatest anomaly on record for Seattle for any date in any year. Tuesday and Wednesday were cooler, but still in the 80s. It breaks the record for most consecutive days in April over 80F, with three (also most days of 75F). We were still breaking record high temperatures for the date last Friday, when a temp of 72F broke the record of 69F from 2012. Last week would have been considered a heatwave in August.

While a repeat of this extreme heat isn't likely anytime soon, the forecast isn't exactly full of rain. In fact, next Monday is forecast for 72F and sun. It's supposed to be rainy with a high around 59F. Given the fact that we just ended the wettest winter in Seattle history, most aren't missing the rain so much as they are disliking this burning ball of fire in the sky ad it's heat related effects.... I'll just say that sun glare is a serious issue when you drive across a floating bridge on a lake, and hot weather absolutely stinks when you have to wear AFO's!

4) W/ the remake of the Arch grounds for its upcoming 50th Anny (which will not be completed by it) all the just maturing ash trees planted in the 80s remake have been removed, as the borer has moved S. Rather than replace w/ variety, going again w/ monoculture. Some London something tree I don't believe is even native (name kind of gives that away). Not sure why some of the ash not in construction zone could not have been left until actually infected so some mature shade still available, but... Really a shame a bug from china shipping materials now decimating another fine native species. Chestnuts, then elms, now ash :(

MO tornado was a minimal EFO, did a little damage in St. Charles county. We had .6" here in S C IL, though others had at least an inch. Looked like about .2 from this mornings at lunch, looks like back edge just about to clear us. Currently 69 w/ 64 dew pt as winds have shifted to S again. Pressure 29.7", about what is was when storm went through yesterday. Supposed to stay in range from 59-70 for highs, 48-56 for lows in 10 day w/ off and on rain chances. Weird April, but not uncommon. So far, not good for morel patch I hunt. Let's Go Blues!
College of DuPage Meteorology
Severe Weather and Flash Flood Warnings
Note: This page will reload every 2 minutes. Warnings are listed with the most recent first.
Click on the station ID to bring up list of recent severe weather statements.
SVR T-STORM WARNING LOUISVILLE KY - KLMK 216 PM CDT WED APR 27 2016
SVR T-STORM WARNING KANSAS CITY/PLEASANT HILL MO - KEAX 210 PM CDT WED APR 27 2016
SVR T-STORM WARNING TOPEKA KS - KTOP 207 PM CDT WED APR 27 2016
SVR T-STORM WARNING KANSAS CITY/PLEASANT HILL MO - KEAX 154 PM CDT WED APR 27 2016
SVR T-STORM WARNING OMAHA/VALLEY NEBRASKA - KOAX 153 PM CDT WED APR 27 2016
SVR T-STORM WARNING TOPEKA KS - KTOP 149 PM CDT WED APR 27 2016
FLASH FLOOD WARNING LOUISVILLE KY - KLMK 247 PM EDT WED APR 27 2016
Quoting 13. Neapolitan:

I agree with most of what you said--but, unfortunately, "Weather geeks like us"--or at least like some of us--were part of the problem, hyping the event for several days. Many here say that we should focus on severe weather outbreaks when they're underway, and I agree. But if we're going to be serious about the forum's value to news-hungry outsiders during severe events, then by the same token we have to be careful to not to fall into the hype trap ourselves.

Of course. You may even be being generous: people like us are probably most of the problem, although "pros" like Mike Morgan obviously contribute as well. Not so much us here at WU, although there are some, and they should be called on it. But elsewhere, there are many anomolously or otherwise shadily run sites by supposed experts who are probably high school students or even less in cases. Very hard to reign in hype when so much information is available.
Quoting 19. Gearsts:




Hopefully not a bust
Coalition Of Scientists Takes Novel Approach To Grading Accuracy Of Climate Change Coverage

A group of scientists from around the world is using new web-based technology to assess the accuracy of media coverage of climate change, and the organization spearheading these efforts is looking for support to take its work to the next level.

The organization, known as Climate Feedback, uses what’s known as web annotation technology to layer scientists’ comments directly onto articles and opinion pieces, so that readers can easily understand whether -- and to what degree -- the pieces are consistent with scientific understanding of climate change. Climate Feedback then assigns a credibility score known as “feedback” to each media piece, which serves as an overall guide to its accuracy -- or lack thereof.

The result looks like this:


Nice rain event IF the GFS is right
Climate Change Drives Half a Billion People to Suffer Hunger, Water Shortages as Droughts and Heatwaves Wreck Crops Across the Globe

At least 12 Indian states are believed to be facing famine and experts have warned that the water crisis could worsen if urgent action is not taken. — Greenpeace statement taken yesterday by The International Business Times.

******

A human-forced warming of the globe is a trigger for increasingly severe droughts, water shortages, food shortages, and heatwaves intense enough to cause mass casualties. As global temperatures during 2015 and 2016 have risen to more than 1 degree Celsius above preindustrial readings, we’ve seen more and more reports coming in of these kinds of climate-change driven disruptions.


Link
Outstanding summary Mr. Henson and you addressed, very well in fact, some of the discussions this morning regarding whether the forecast was "bust" per say.  Weather forecasting is not an exact science and it is so easy for non-scientists/non-mets in this case to play armchair quarter back (and in our case keyboard quarterbacks) when NOAA is doing the best that they can using the best forecast tools, and professional mets, in the business to give the public adequate advance knowledge of severe weather events.  Their primary mission is to try to save lives and they do a very good job across the board...................It is Mother Nature that occasionally throws the curve ball.   
Indeed, because the challenge is so great, Climate Feedback is ramping up its efforts via a crowdfunding campaign this week. The aim is to raise enough funds to hire a scientific editor and build a “Scientific Trust Tracker,” which will aggregate the group’s ratings to assess the overall credibility of various news sources. According to Vincent, the new tool “should provide a healthy incentive for more accurate science reporting,” because “building trust is essential for news sources and scientists’ endorsements can help journalists with integrity to get ahead.”
Climate Feedback: A guide to reliable climate news
Whether it was a bust, bad forecast or whatever? So what. There was an expectation yesterday of tornadoes, some dangerous long track. A PDS was issued, TORCON values were relatively high, TWC went 24/7 coverage, and Storm Chasers were on the streets in full force. Seldom does this type of a forecast miss but that's weather. For those living in that area I'm quite sure they are happy and relieved today. Unfortunately we have a long time to go for this spring's tornado season so the next time we may not be so lucky.
Quoting 23. CaribBoy:


Looks like sst have warmed in the MDR region.
Today is the 5th anniversary of the Tornado outbreak here in the south. I remember that day like it was yesterday as we stayed huddled together in our make shift storm shelters. We had 2 rounds of storms that day but the evening was the worst. Here in southeast Tennessee my county had 9 deaths that night from a Tornado measured at a high end Ef4. Since that day our area still has no Tornado sirens but local weather people stress the importance of a weather radio alert. You can prepare for a hurricane in advance and evacuate if needed. Tornadoes are one factor that no one should ever let there guard down. If your officials give advisories of impending bad weather be prepared and use common sense. The word will get out if that day your weather could be intense. So if your warned of impending Tornadoes and nothing happens we all win.

Here are the current reports (the last 3 hours) as of this afternoon and the pending climatology for May: will also note that there are two current warnings up near the Nebraska-Iowa border region.

last3hours Reports Graphic
may_tornado_zones_2016

Quoting 28. washingtonian115:

Looks like sst have warmed in the MDR region.



Yes they have.



Its been very rainy here in PR, in the last couple of days. I had not heard thunder since I think last year around November, and these past couple of days its been booming all over the place, and more rain is expected through the upcoming weekend, maybe even beyond. Soils are already saturated, and if the amount of rain that is expected to fall these next few days (good model consensus), I wont be surprised if they issue a Flash Flood Watch. Compare this to last year, the drought was just beginning. Today all the main reservoirs are full, and rainy season is just around the corner, if its not already. No rationing of water this year. Fingers crossed :)



FLASH FLOOD WARNING
PRC089-119-272230-
/O.NEW.TJSJ.FF.W.0006.160427T2026Z-160427T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000 Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN JUAN PR
426 PM AST WED APR 27 2016

THE NATIONAL WEATHER SERVICE IN SAN JUAN HAS ISSUED A

* FLASH FLOOD WARNING FOR...
LUQUILLO MUNICIPALITY IN PUERTO RICO...
RIO GRANDE MUNICIPALITY IN PUERTO RICO...

* UNTIL 630 PM AST

* AT 424 PM AST...DOPPLER RADAR INDICATED A THUNDERSTORM PRODUCING
HEAVY RAIN ACROSS THE WARNED AREA...ESPECIALLY IN SECTOR PUENTE
ROTO AND ALONG THE MAMEYES RIVER. FLASH FLOODING IS EXPECTED TO
BEGIN SHORTLY.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
LUQUILLO...HATO CANDAL...PLAYA FORTUNA AND PALMER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO HIGHER GROUND NOW. ACT QUICKLY TO PROTECT YOUR LIFE.

&&

LAT...LON 1840 6577 1839 6575 1838 6575 1838 6574
1839 6572 1838 6571 1830 6573 1830 6575
1828 6577 1830 6580 1841 6579 1841 6577

$$

DS
Cody I never before saw a forecast graphic for peak tornado strength. The graphic makes no sense to me--what's to stop an EF4 from becoming an EF5 for a minute?

MAweatherboy1 thanks for posting Angela Fritz's article.
Quoting 27. luvtogolf:

Whether it was a bust, bad forecast or whatever? So what. There was an expectation yesterday of tornadoes, some dangerous long track. A PDS was issued, TORCON values were relatively high, TWC went 24/7 coverage, and Storm Chasers were on the streets in full force. Seldom does this type of a forecast miss but that's weather. For those living in that area I'm quite sure they are happy and relieved today. Unfortunately we have a long time to go for this spring's tornado season so the next time we may not be so lucky.

It absolutely matters. When you have a meteorologist in the most severe weather-prone market in America giving a maxed out tornado forecast with the potential for EF4 tornadoes, and when you have a PDS Tornado Watch with 90/80 probabilities, and those forecasts don't materialize, some members of the public may perceive additional threat warnings as crying wolf. They're less likely to take shelter, and a result more people die in outbreaks.


Widespread loss of ocean oxygen to become noticeable in 2030s

A reduction in the amount of oxygen dissolved in the oceans due to climate change is already discernible in some parts of the world and should be evident across large regions of the oceans between 2030 and 2040, according to a new study led by the National Center for Atmospheric Research (NCAR).

Read more at: Link
Quoting 28. washingtonian115:

Looks like sst have warmed in the MDR region.

Quoting 31. 882MB:



Yes they have.






Well I was expecting this to happen and I'd expect it to continue over next few days
The vertical instability in the tropical Atlantic is getting closer to normal. Not sure if it will stay this way, but it's something to keep an eye on. Also, I wouldn't rely completely on a cold MDR for 2016 - last year the MDR warmed up a LOT in August and September. Keep that in mind. Also, it appears as if the "Cold Blob" in the Northern Atlantic is weakening. This does not mean we are headed for a +AMO, but, it likely means that we are not in a solid -AMO, or at least not just yet.
Quoting 35. RobertWC:



Widespread loss of ocean oxygen to become noticeable in 2030s

A reduction in the amount of oxygen dissolved in the oceans due to climate change is already discernible in some parts of the world and should be evident across large regions of the oceans between 2030 and 2040, according to a new study led by the National Center for Atmospheric Research (NCAR).

Read more at: Link



I found this bit interesting

Warming surface waters, however, absorb less oxygen. And in a double whammy, the oxygen that is absorbed has a more difficult time traveling deeper into the ocean. That's because as water heats up, it expands, becoming lighter than the water below it and less likely to sink.

That's a positive feedback effect that I wasn't aware of. The ocean is a gigantic heat sink. More than 90% of the surface warming caused by GHGs is believed to be absorbed by the ocean. But if the extra heat from warming causes this kind of stratification, then a greater proportion of future warming will warm the atmosphere. It just gets worser and worser.
Quoting 34. TropicalAnalystwx13:


It absolutely matters. When you have a meteorologist in the most severe weather-prone market in America giving a maxed out tornado forecast with the potential for EF4 tornadoes, and when you have a PDS Tornado Watch with 90/80 probabilities, and those forecasts don't materialize, some members of the public may perceive additional threat warnings as crying wolf. They're less likely to take shelter, and a result more people die in outbreaks.


Obviously I can't speak for everyone, but I don't think most people in Oklahoma are going to ignore severe weather warnings in the future just because we didn't get a town wiped off the map last night. We still had an incredibly severe line of storms go through the state that did significant wind and hail damage in places. The prevailing attitude is gratitude that it wasn't worse. Also, the meteorologists I watched last night did a good job of explaining why we didn't get more tornadoes.
Quoting 28. washingtonian115:

Looks like sst have warmed in the MDR region.


Yup - could use even more warming in the east.

Nice illuminating overview of Pacific Decadal Oscillation. - for full research paper pdf see The Pacific decadal oscillation, revisited



" . . . since much of the PDO represents the oceanic response to atmospheric forcing, care should be taken when using the PDO as a forcing function of non-oceanic responses without a convincing argument for the physical forcing mechanism. What this means is that a correlation with the PDO does not necessarily imply that the PDO is the driver but more likely that there is a common forcing function shared between the PDO and the process being investigated."




It's important to note that the PDO has a lagged response to its inter-related oscillations, etc.- such as El Nino. So it will be interesting to see what degree April's and May's PDO index tracks with the shift toward La Nina. The longer it goes without tracking, i.e. staying more positive, then statistically it is more likely to correlate with a reduced intensity of La Nina. For a more in-depth article see The Relationship Between the PDO and ENSO.

What is known:

The potential for very heavy rain on Saturday remains a concern, however precipitable water levels are likely to be a bit lower than we saw during the Tax Day rains, and conditions otherwise won%u2019t be quite as conducive for extremely heavy rainfall

At this time pro mets guess most of us will see 2 to 4 inches of rain, yet although it remains possible there will be some bullseyes with 5 inches of rain in southeast Texas. Where? Good question. But some of the experts think they will not occur over western Harris County, where the heaviest rains were about 10 days ago.


My questions:


1. Does this mean HOUSTON itself is in a more comfortable position stormwise than 10 days ago or, for that matter, today?

2. Unfortunately with our saturated ground, the bow echo was just too much for many trees across the Region. The Storm Prediction Center is expecting a somewhat similar situation Friday into Saturday. Look:

http://www.spc.noaa.gov/products/exper/day4-8/day 4prob.gif?1461802258115


If this verifies, given the saturated ground, the number of downed trees and power lines will be TRIPLE what it was today?


Would like answers ASAP.


Oh, one more thing:




If this verifies, would it show up as a bow echo on radar, leading to my usual worries (power, downed trees, et. al.)?
I wonder on what climatology range of years, this graph of SST anomalies is based, because looks different to the one in Levi's site.



Quoting 39. yonzabam:



I found this bit interesting

Warming surface waters, however, absorb less oxygen. And in a double whammy, the oxygen that is absorbed has a more difficult time traveling deeper into the ocean. That's because as water heats up, it expands, becoming lighter than the water below it and less likely to sink.

That's a positive feedback effect that I wasn't aware of. The ocean is a gigantic heat sink. More than 90% of the surface warming caused by GHGs is believed to be absorbed by the ocean. But if the extra heat from warming causes this kind of stratification, then a greater proportion of future warming will warm the atmosphere. It just gets worser and worser.


Scribbler has pointed this out more than once (stratification) . If you want to read more there's a thing called a "Canfield Ocean" . It's a really grim look at the past -

Canfield ocean -


The Canfield Ocean model was proposed by geochemist Donald Canfield to explain the composition of the ocean in the middle to late Proterozoic. His theory has been coined the 'Canfield Ocean' and remains one of the cornerstone theories of ocean oxygen composition during that time.


Posts about Canfield Ocean written by robertscribbler.

The oceans turn to a weak battery acid soup, producing H2S bacteria.

Would like answers ASAP.

You want answers. I don't think you are capable of handling the truth. You posted charts, you posted what the pro mets are forecasting. What else are you looking for? Someone with zero experience in forecasting on this blog to tell you that death and destruction will hit your neighborhood on Saturday? If I were you I would move to the desert.


The Greenland heatwave seems to be ebbing after today –

Nuuk, Greenland

Today
High 60 | Low 35 °F

Average

High 32 °F – Low 26 °F

Link
Dayko, a 4-year-old Labrador in the Ibarra fire department’s K9 unit, was part of a search-and-rescue team that has been working to find survivors.................. Local news reports said the rescue dog saved seven people before his death.

Firefighters in Ecuador said a rescue dog that helped save victims trapped under rubble after this month’s devastating recent earthquake died from heatstroke while performing his duties.
47. luvtogolf

Try decaf.
Quoting 49. RobertWC:

Dayko, a 4-year-old Labrador in the Ibarra fire department’s K9 unit, was part of a search-and-rescue team that has been working to find survivors.................. Local news reports said the rescue dog saved seven people before his death.

Firefighters in Ecuador said a rescue dog that helped save victims trapped under rubble after this month’s devastating recent earthquake died from heatstroke while performing his duties.


He or She or canine that stop's to help another is favored by God and the Universe.

Quoting 12. TropicalAnalystwx13:


It doesn't help when you have people like Mike Morgan releasing these kind of graphics:






That is ridiculous, where the heck did they come up with that?
Quoting 47. luvtogolf:

Would like answers ASAP.

You want answers. I don't think you are capable of handling the truth. You posted charts, you posted what the pro mets are forecasting. What else are you looking for? Someone with zero experience in forecasting on this blog to tell you that death and destruction will hit your neighborhood on Saturday? If I were you I would move to the desert.


AccuWeather Met Edward Vallee said that the slow-moving nature of the storm system will also bring an elevated risk of flash flooding. "The greatest threat for flash flooding will be north of areas hit hard by flash flooding last week," Vallee said. There is the potential for 3-6 inches of rain to fall on parts of western Louisiana and northeastern Texas. Of that rainfall, a couple of inches could fall in as many hours on some communities.

That's good news for us in Houston.

The trouble is, localized flooding could develop in our area, because our city tends to flood often during heavy rain events.

I think they're just saying that for safety's sake. I still worry about uprooted trees and downed power lines, though. I only asked if TRIPLE the number of both maladies we saw today will occur if the area gets heavy rains Saturday. TropicalAnalyst, can you help me?


Quoting 51. Patrap:



He or She or canine that stop's to help another is favored by God and the Universe.




Dogs, not one cat has ever saved some one . Well, maybe one sat on some one's face when the house was on fire. But dogs, made the modern world possible, just like salt, fire, and the invention of the sail.
Quoting 45. stormchaser19:

I wonder on what climatology range of years, this graph of SST anomalies is based, because looks different to the one in Levi's site.






Hey buddy, if you look closely, you can tell the difference, I know its hard to tell, so many colors..... :)
Comment removed. Personal content.
Quoting 33. BaltimoreBrian:

Cody I never before saw a forecast graphic for peak tornado strength. The graphic makes no sense to me--what's to stop an EF4 from becoming an EF5 for a minute?

MAweatherboy1 thanks for posting Angela Fritz's article.

Quoting 52. Jedkins01:



That is ridiculous, where the heck did they come up with that?

We are talking about the guy that warned people to get in their vehicles and drive south away from the El Reno tornado, after all.
Hi TA13,
Dare you and anyone else who wants to criticize what happens in Oklahoma to live in central OK for a few years. You know, Moore, Norman, OKC metro... :) Or maybe Woodward.


Well, at least on THIS run of the GFS, the worst is to the NE of Houston/Harris County. Hope our pro mets have seen it.
last year

and this year
(photo and caption removed)
Quoting 58. Barefootontherocks:

Hi TA13,
Dare you and anyone else who wants to criticize what happens in Oklahoma to live in central OK for a few years. You know, Moore, Norman, OKC metro... :) Or maybe Woodward.

Nah, I'm more of a country guy. :)
Figure 1. Preliminary reports of severe weather received by the NOAA/NWS Storm Prediction Center for the period from 12Z (8:00 am EDT) Thursday, April 26, 2016, through 12Z Wednesday.

Hey Bob,
Not sure this was pointed out but I think you meant Tuesday through Wednesday.

BTW, yes I do read your guys post!
And so we approach another complicated forecast. The SPC just released their outlook for Friday, highlighting a Slight risk over portions of Texas and Oklahoma. The GFS and NAM could not be further apart with regard to the potential for tornadoes across central Oklahoma in particular. The NAM shows a much stronger trough, with more westerly flow in the mid- to upper levels. The GFS is more meridonal, which could bring some veer-back-veer issues to the table (again). Both models show convection ongoing Friday morning, but the GFS is much more extensive; as a result, it shows less instability than the NAM. Finally, the 850mb low placement on the GFS is in the Texas Panhandle, whereas the NAM has it in Central Kansas. This makes a huge difference in terms of directional shear. A solution like the GFS shows would result in a few severe storms mainly capable of producing large hail and maybe a brief spin-up across central Oklahoma. The NAM would result in a localized tornado outbreak, with the potential for significant tornadoes.

Oy...
Quoting 52. Jedkins01:



That is ridiculous, where the heck did they come up with that?


lol, we don't even have a baseline (as far as I know) that quantifies as a starting point for tornadoes reaching EF4 strength. That's why SPC uses "strong tornado" to indicate EF3 or higher.
Quoting 52. Jedkins01:



That is ridiculous, where the heck did they come up with that?


So he comes up with a 10/10???? Forbes must have face palmed. Wow, that's as unprofessional as one gets. Talk about inducing fear through a total misread of forecast. Could have been really bad, but he should have waited for conditions to verify. Which they never did. Epic day, but tornado outbreak no.
Quoting 28. washingtonian115:

Looks like sst have warmed in the MDR region.



Most of that is actually just outside the actual MDR.
The Atlantic MDR :
It does not include the warm waters SW of Haiti.

50% chances we see a tropical storm nw carib in late May early June
Big thunderstorms already blowing up in East Mississippi, wow!
Seriously? The CFS shows a strong La Niña in JUNE???
Quoting 65. KoritheMan:



lol, we don't even have a baseline (as far as I know) that quantifies as a starting point for tornadoes reaching EF4 strength. That's why SPC uses "strong tornado" to indicate EF3 or higher.


There is some "box & whisker" statistical guidance out there in forecast and real-time soundings tied to the climatology of tornado parameters.

spc.noaa.gov/experimental environmental browser
spc.noaa.gov/severe weather parameters

ADDED: But you're right. There is no way to forecast a particular classification using a scale based on post-event damage assessment.

Quoting 67. MahFL:

For the layman Tuesdays forecast was a total bust.
For the layman who doesn't understand probabilities, and who gets his weather info only from hype-prone outlets, and who may have poor reading comprehension skills on top of that, yes, Tuesday's forecast may have seemed like a "bust". But if a person who doesn't understand probabilities and odds cashes in his 401k to purchase scratch-off lottery tickets, who's to blame when he winds up broke?

I understand Ms Fritz's statement that professional weather organizations can and should do a better job communicating the risks. But I imagine professional mets must be very frustrated that some people still just don't get it. If they over-forecast by even a smidge, they're accused of "crying wolf" and, thus, jeopardizing lives and property. If they under-forecast by a tiny percent, they're accused of "downplaying the risks" and jeopardizing lives and property. If they're spot-on with their forecasts--as they were Tuesday--they're accused of not ensuring that their message was heard above the din of the hype-mongers recklessly forecasting a weather catastrophe, thereby jeopardizing lives and property.

Bottom line is, I guess I just don't see how, after putting out a very accurate weather forecast, they're at all to blame for doofuses like Mike Morgan who cherry-picked that forecast and went full on Chicken Little, complete with angry red and blue graphics and big scary fonts intended solely to scare the beejeezus out of everyone in Oklahoma.
Good Morning Folks: here is the Conus forecast for today:

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
431 AM EDT Thu Apr 28 2016

Valid 12Z Thu Apr 28 2016 - 12Z Sat Apr 30 2016

...There is a slight risk of severe thunderstorms over parts of the
Southern Plains and over parts of the Southern Mid-Atlantic...

...Heavy rain possible over parts of the Southern Plains/Lower Mississippi
Valley and parts of the Central Plains...

...Snow over parts of the Central Rockies...
And the current look and jet position:
Doppler Radar National Mosaic Loop
And the 5:00 pm highs for today; going from Spring right to Summer temps in the SE today:



And finally the US drought monitor for today: pretty obvious that the El Nino rains for this particular season, while soaking many parts of the US lately, keep missing Southern California to the North and South......................................


Current U.S. Drought Monitor
The parameters of projecting where storms would fire on Tuesday was a virtual impossibility to nail down exact conditions. Low level wind shear was the big key to unlock whether or not this would be a tornado outbreak. A very difficult forecast and the SPC really nailed the areas and impacts. Ten % across the board tornado risk showed the SPC understood very clearly that the tornado risk may not verify. They did an amazing job.
Quoting 74. Neapolitan:

For the layman who doesn't understand probabilities, and who gets his weather info only from hype-prone outlets, and who may have poor reading comprehension skills on top of that, yes..


So how come 2000 + storm-chasers, many with 30 years of experience were out expecting multitudes of tornadoes ?
Quoting 79. luvtogolf:

For the layman who doesn't understand probabilities, and who gets his weather info only from hype-prone outlets, and who may have poor reading comprehension skills on top of that, yes, Tuesday's forecast may have seemed like a "bust". But if a person who doesn't understand probabilities and odds cashes in his 401k to purchase scratch-off lottery tickets, who's to blame when he winds up broke?


I wonder what someone did to you to have so much hate and criticism for the rest of the world for not being perfect.


Because we ended up with close to 600 damage reports on Tuesday. To call Tuesday a bust ignores they got 9/10 of the conditions correct. This was a forecast with conditions beyond our ability to forecast far out for exact impacts. Such is the nature of climate. This was a top end difficulty forecast. One with no understanding of that could judge the SPC harshly with no real understanding nor appreciation of how difficult their job really is.
Quoting 81. MahFL:



So how come 2000 + storm-chasers, many with 30 years of experience were out expecting multitudes of tornadoes ?


Because they were looking at the same conditions the SPC were and had the low level winds picked up earlier we would have had an outbreak. All the parameters were there, but how they all came together during the day was incredibly difficult to nail down. So these chasers, many with 30 yrs of experience, some with met degrees; they're all forecast failures too?
Quoting 81. MahFL:



So how come 2000 storm-chasers, many with 30 years of experience were out expecting multitudes of tornadoes ?


TWC went with 24/7 coverage (for an expected damaging hail threat?) TORCON values were at a 6. A PDS was also issued. They missed. It won't be the last either. It's not a perfect science.
Quoting 80. DeepSeaRising:

The parameters of projecting where storms would fire on Tuesday was a virtual impossibility to nail down exact conditions. Low level wind shear was the big key to unlock whether or not this would be a tornado outbreak. A very difficult forecast and the SPC really nailed the areas and impacts. Ten % across the board tornado risk showed the SPC understood very clearly that the tornado risk may not verify. They did an amazing job.



I disagree, they had the PDS tornado box up for hours after it was obvious no strong tornadoes were going to form.
Quoting 53. pureet1948:



AccuWeather Met Edward Vallee said that the slow-moving nature of the storm system will also bring an elevated risk of flash flooding. "The greatest threat for flash flooding will be north of areas hit hard by flash flooding last week," Vallee said. There is the potential for 3-6 inches of rain to fall on parts of western Louisiana and northeastern Texas. Of that rainfall, a couple of inches could fall in as many hours on some communities.

That's good news for us in Houston.

The trouble is, localized flooding could develop in our area, because our city tends to flood often during heavy rain events.

I think they're just saying that for safety's sake. I still worry about uprooted trees and downed power lines, though. I only asked if TRIPLE the number of both maladies we saw today will occur if the area gets heavy rains Saturday. TropicalAnalyst, can you help me?





You already have a very good grasp on the situation. No one here can add any more to the information you have at hand. You are aware of saturated ground conditions, you are aware of what straight line winds can do to trees, you've done your homework. Continue to monitor the situation as it evolves. No one here can tell you exactly what's going to happen.
Quoting 44. pureet1948:

The potential for very heavy rain on Saturday remains a concern, however precipitable water levels are likely to be a bit lower than we saw during the Tax Day rains, and conditions otherwise won%u2019t be quite as conducive for extremely heavy rainfall

At this time pro mets guess most of us will see 2 to 4 inches of rain, yet although it remains possible there will be some bullseyes with 5 inches of rain in southeast Texas. Where? Good question. But some of the experts think they will not occur over western Harris County, where the heaviest rains were about 10 days ago.


My questions:


1. Does this mean HOUSTON itself is in a more comfortable position stormwise than 10 days ago or, for that matter, today?

2. Unfortunately with our saturated ground, the bow echo was just too much for many trees across the Region. The Storm Prediction Center is expecting a somewhat similar situation Friday into Saturday.


If this verifies, given the saturated ground, the number of downed trees and power lines will be TRIPLE what it was today?


Would like answers ASAP.">


If this verifies, would it show up as a bow echo on radar, leading to my usual worries (power, downed trees, et. al.)?


1. Very difficult to answer as the Houston forecast seems to be very tricky at times, especially to the amount of rainfall. Very few of the floods came with any warning (Tax Day, Memorial Day and even the remnants of TS Allison) Typically a "perfect storm" of conditions usually occur that cause the flooding that is very difficult to forecast. If the present forecast holds true, no more flooding should occur but everything is so saturated 5 Inches of rain over a large area will reek havoc.

2. Straight line wind damage is very difficult to predict here. Just always be prepared. Typically the more severe storms run from a line from Huntsville to Livingston. The damage caused can not be predicted very easily. (see comment 1) Falling trees from saturated grounds do not need a lot of wind as they usually fall very slowly lifting up the lawn, while higher winds will snap branches and full size trees and but will also lay them down intact with the root structure exposed. (again, these trees that do not snap but rather bend from the ground up are a little slower than gravity.

3. Don't spend your time worrying, spend your time getting ready. Tarps, generators and a good knowledge of low spots that flood more easily than others should be avoided. If the big rains hit, just stay home.

I have lived in Houston for over 50 years and my best advice to expect the worst and hope for the best. At least this is not the drought and temps from a few years ago. While the forecast are usually pretty good, the forecast of extreme weather is wrong more than right and vice versa.

As they say in these parts, "Don't like the weather? Give it 5 minutes!"

Last thing. Buy Flood Insurance. Every time it floods there is always someone on the news saying "It has never flooded here before." I always assume that my house will be flooded at some time in the future and have been lucky so far.

On the other hand, my fathers house has been crushed by a huge oak tree that snapped during Ike, flooded over the memorial day floods and stayed high and dry for the recent tax day floods.
Quoting 45. stormchaser19:

I wonder on what climatology range of years, this graph of SST anomalies is based, because looks different to the one in Levi's site.







The original 36-km satellite-only reprocessed SST data used for creating the climatologies were generated from the Multi-Channel SSTs (MCSSTs) by the Rosenstiel School of Marine and Atmospheric Science (RSMAS) at the University of Miami (Gleeson and Strong, 1995). In situ SSTs from drifting and moored buoys were used to remove any biases, and statistics were compiled with time to derive the reprocessed SSTs. The monthly mean SST climatologies were then derived by averaging these satellite SSTs during the time period of 1985-1993. Observations from the years 1991 and 1992 were omitted due to the aerosol contamination from the eruption of Mt. Pinatubo. These climatologies were developed at NOAA/NESDIS/STAR (then ORA) before being delivered to NESDIS/OSPO (then OSDPD) for implementation. The 36-km climatologies were finally interpolated into 0.5-degree (50-km) resolution to match the resolution of the operational SST analysis field.


Link
An article of interest on the issue of freshwater for human consumption given the current droughts that we are seeing in many parts of the world..........A solar water "still"..............................A great idea that looks like a cross between something you would see in the backyard or back of a boat or dune buggy in the Mad Max series or Water World...........................

http://www.sciencemag.org/news/2016/04/new- water-purification-system-could-help-slake-world-s -thirst

More than 1 billion people around the world lack access to fresh water, and the problem is growing: By 2025 a whopping two-thirds of the world's population may face water shortages. To slake that thirst, some wealthy communities have invested in water desalination plants that turn salt water into clean drinking water. But these plants are too expensive for most communities to afford. Now, researchers have come up with a solar-powered technique that could make small-scale desalination systems affordable, even for individual households.

The approach is a new take on an old technology known as a solar still. These stills are large containers covered by clear plastic tarps or glass enclosures that direct sunlight onto a basin of salty water. Water evaporates, leaving salts behind, and then condenses on the plastic or glass, where it is captured. The trouble is throughput. The sun evaporates water so slowly that very little fresh water is produced and too little for most people to even bother.

Cheap aluminum foil dramatically boosts the ability of sunlight to desalinate water.

As Bob Henson said, was the forecast a bust, depends on your perspective, so for me to say I think the forecast was a bust is justified.
Also on a side note a chaser I was watching said that every time he's come out chasing on a MOD risk day where all hell was supposed to break out, nothing had happened, not sure how many times that was, but it was his genuine feeling about the previous forecasts.
The danger is of course the next time a forecast like this occurs and all hell does break loose, people might have become complacent, which makes forecasters jobs pretty difficult at times.
Dr. Timmer has upgraded his forecast to a "High Risk" for tornadoes across parts of Oklahoma and Kansas.

Upgraded Tornado Threat Across Parts of Western OK and KS!
Dr. Reed Timmer, Lead Meteorologist April 26, 2016

The tornado threat has been upgraded to the high (4/5) category in two locations within the broader risk area: 1. Near I-70 corridor in vicinity of outflow boundary around 4-7 pm with enhanced low level shear, and 2. western OK into southern KS along dry line especially after 6-7 pm when low-level wind shear increases.


I guess he nailed it too.
i think the forecast was excellent. small details like upper level wind profile devolving into unfavorable can be seen as a blessing as far as i am concerned!
Quoting 92. FyrtleMyrtle:

i think the forecast was excellent. small details like upper level wind profile devolving into unfavorable can be seen as a blessing as far as i am concerned!


Agree it was a blessing. However, a PDS was issued. Was that an excellent forecast? A PDS is not frequently issued by the SPC.
The predictors i am now seeing could translate to a more active season.
So if I interpret this correctly the MDR sea surface temps have warmed nicely during the last 7 days ?

Quoting 94. stoormfury:

The predictors i am now seeing could translate to a more active season.


Stormfury, Please share your predictors.
Quoting 95. MahFL:

So if I interpret this correctly the MDR sea surface temps have warmed nicely during the last 7 days ?




I'm certainly no expert but it looks like to me that the SST's are warming. Getting close to the 2016 season.
Quoting 81. MahFL:

So how come 2000 + storm-chasers, many with 30 years of experience were out expecting multitudes of tornadoes ?
I would imagine for the same reason that people queue up for scratch-off lottery tickets.
Quoting 87. uptxcoast:



I have lived in Houston for over 50 years and my best advice to expect the worst and hope for the best. At least this is not the drought and temps from a few years ago. While the forecast are usually pretty good, the forecast of extreme weather is wrong more than right and vice versa.





It seems to me that no matter where you live and who you are, if you were expect the worst and hope for the best in every aspect of your life, things would be a whole lot easier for pretty much everybody...........
100. MahFL
Brrrr :

"Forecasters have issued warnings for snow in many parts of Scotland as a dip in April temperatures continues."
Quoting 93. luvtogolf:



Agree it was a blessing. However, a PDS was issued. Was that an excellent forecast? A PDS is not frequently issued by the SPC.
You are aware, I assume, what a PDS is, right? PDS tornado watches are issued when forecasters have high confidence that multiple strong or violent tornadoes will occur in the watch area. Note that "high confidence" part; that passage doesn't say "PDS tornado watches are issued when forecasters are 100% certain that strong or violent storms will occur." Now, there were indeed "numerous strong or violent tornadoes in the watch area". There weren't many dozens of twisters, and there were no EF5s, true. But both the forecast and the watch were warranted. Had that cap weakened, all hell would have broken loose. And *that's* why the PDS was issued.
Lots of talk about second guessing the pro mets on here lately so here is my entry into the fray; Forget the pre-season forecasts for the Atlantic.......................25 storms and 6 major hurricanes...................... lol
Quoting 40. gunhilda:



Obviously I can't speak for everyone, but I don't think most people in Oklahoma are going to ignore severe weather warnings in the future just because we didn't get a town wiped off the map last night. We still had an incredibly severe line of storms go through the state that did significant wind and hail damage in places. The prevailing attitude is gratitude that it wasn't worse. Also, the meteorologists I watched last night did a good job of explaining why we didn't get more tornadoes.


Five out of six rounds of Russian Roulette have an outcome of no consequence. That does not make people less aware of the risk of the next round
.Quoting: 96 bucsboltsfan


Stormfury, Please share your predictors.

1 SAL is not as dense thereby allowing the atlantic to warm
2 easterly trades are light
3 sst in the MDR are now getting warmer
4 the cold pool in the north atlantic is warming
5 it is wetter than usual in the SAHEL region of Africa
and the most important is La Nina is rapidly being established and early than forecast.
Between now and July, SAL coverage (or non-coverage) will help dictate some of the surface temps across the Atlantic MDR as it waxes and wanes......................Somewhat heavy out there at the moment but will also note that the ITCZ is looking pretty healthy at the moment in April with the Sahel rainy season peak still to come in June:





Quoting 104. stoormfury:

.Quoting: 96 bucsboltsfan


Stormfury, Please share your predictors.

1 SAL is not as dense thereby allowing the atlantic to warm
2 easterly trades are light
3 sst in the MDR are now getting warmer
4 the cold pool in the north atlantic is warming
5 it is wetter than usual in the SAHEL region of Africa
and the most important is La Nina is rapidly being established and early than forecast.



Ok, let's see what happens. Wonder if we'll get a May storm?
A person who drives a 2 door sedan into a strong Hail core is not a stormchaser, He is a fool.

Easily.



Quoting 101. Neapolitan:

Now, there were indeed "numerous strong or violent tornadoes in the watch area".


Source?
Quoting 103. georgevandenberghe:



Five out of six rounds of Russian Roulette have an outcome of no consequence. That does not make people less aware of the risk of the next round

Actually each of those five rounds (of empty chambers) do have an outcome of consequence - they make the odd of a hit next round bigger. In this easy to parse case indeed people are quite aware.
Quoting 100. MahFL:

Brrrr :

"Forecasters have issued warnings for snow in many parts of Scotland as a dip in April temperatures continues."

So not news back in dem days.
#89:
Link
Great minds?
Workers face 'epidemic of heat related injuries' due to climate change

Link
Starting the process of taking the snow tires off the cars, we've had our last snow for the season this week. Every day I take a few moments to come here, read the blog, and get my weather fix. Will be interesting to see how the weather progresses through to summer for sure.
Quoting 68. MahFL:



Most of that is actually just outside the actual MDR.
I know exactly what the MDR is.I was responding to a post that posted the latest warming in the MDR all while posting the weekly TCHP.I'm not stupid and I know that the warmest of waters right now are centered in the caribbean.
Quoting 101. Neapolitan:

You are aware, I assume, what a PDS is, right? PDS tornado watches are issued when forecasters have high confidence that multiple strong or violent tornadoes will occur in the watch area. Note that "high confidence" part; that passage doesn't say "PDS tornado watches are issued when forecasters are 100% certain that strong or violent storms will occur." Now, there were indeed "numerous strong or violent tornadoes in the watch area". There weren't many dozens of twisters, and there were no EF5s, true. But both the forecast and the watch were warranted. Had that cap weakened, all hell would have broken loose. And *that's* why the PDS was issued.


I guess I missed that there were numerous strong or violent tornadoes on Tuesday.
Quoting 110. cRRKampen:


Actually each of those five rounds (of empty chambers) do have an outcome of consequence - they make the odd of a hit next round bigger. In this easy to parse case indeed people are quite aware.


I don't engage in this practice and had not thought about not randomizing by spinning the chamber. If that's not done the outcome obviously depends on previous results.
Quoting 116. luvtogolf:



I guess I missed that there were numerous strong or violent tornadoes on Tuesday.
There were4 no violent tornadoes, as I noted earlier. And the PDS called for a high chance of strong or violent twisters, not strong and violent". Anyway, survey teams are still out, but this is nonetheless a pretty good picture of a severe weather outbreak:



At any rate, we're going around in circles here, so I'm stepping off this particular merry-go-round. Anyone holding the personal opinion that the Tuesday forecast was a "bust" is free to do so (despite the fact that it wasn't); I'll not try to sway them. Cheers!
Quoting 118. Neapolitan:

There were4 no violent tornadoes, as I noted earlier. And the PDS called for a high chance of strong or violent twisters, not strong and violent". Anyway, survey teams are still out, but this is nonetheless a pretty good picture of a severe weather outbreak:



At any rate, we're going around in circles here, so I'm stepping off this particular merry-go-round. Anyone holding the personal opinion that the Tuesday forecast was a "bust" is free to do so despite the fact that it wasn't.


It was a bust. Get over it and move on.
Quoting 115. washingtonian115:

I know exactly what the MDR is.I was responding to a post that posted the latest warming in the MDR all while posting the weekly TCHP.I'm stupid and I know that the warmest of waters right now are centered in the caribbean.


Getting ready for my mid-may fishing trip in the Central Bahamas with work colleagues I've known for decades.
Many years the GFS spins something up in the Carribean about this time.. surely just to unnerve me :-)
14/6/2.5 my predictions....
JeffMasters has created a new entry.
Quoting 47. luvtogolf:

Would like answers ASAP.

You want answers. I don't think you are capable of handling the truth. You posted charts, you posted what the pro mets are forecasting. What else are you looking for? Someone with zero experience in forecasting on this blog to tell you that death and destruction will hit your neighborhood on Saturday? If I were you I would move to the desert.


Apparently (s)he is looking for an arborist to predict exactly which trees in the metropolitan area will fall if it rains on Saturday.
Quoting 119. luvtogolf:



It was a bust. Get over it and move on.
No, it wasn't. But I have moved on; did you not read the end of my comment? Here, I'll reproduce it for you:

"I'm stepping off this particular merry-go-round. Anyone holding the personal opinion that the Tuesday forecast was a "bust" is free to do so (despite the fact that it wasn't); I'll not try to sway them. Cheers!"
...a PDS Tornado Watch with a high risk for tornadoes and a high risk for EF2 plus and enclosing a handful of EF0 and EF1s, is overdone. Next!...
Quoting 125. Barefootontherocks:

...a PDS Tornado Watch with a high risk for tornadoes and a high risk for EF2 plus and enclosing a handful of EF0 and EF1s, is overdone. Next!...
People are certainly free to espouse that opinion, even if in doing so they belie a lack of understanding in what a PDS--or any sever weather watch--actually is. Watches mean that conditions are ripe and the potential; exists; it doesn't mean it's a certainty.

And *now* next...