If global warming is occurring, why was the winter of 2007-2008 so cold and snowy?

By: Dr. Jeff Masters , 1:38 PM GMT on March 14, 2008

Share this Blog
7
+

The planet was much snowier and warmer than usual during the winter of 2007-2008, according to statistics released today by the National Climatic Data Center. Snow cover extent over the Northern Hemisphere during the period December 2007 - February 2008 was the fourth greatest on record, and was the greatest on record for January. Satellite-derived snow cover records extend back to 1967. Some regions of the Middle East, such as Baghdad, Iraq saw their first snow in living memory, and seasonal snowfall records were broken in Wisconsin and a few places in the Northeastern U.S. Surprisingly, the winter also ranked much above average in temperature--it was the 16th warmest December through February period in the 128-year global record. This puts the winter of 2007-2008 in the warmest 13% of all winters. Temperatures this winter were a bit cooler than recent winters because of an ongoing strong La Niña event in the Eastern Pacific Ocean, which has dramatically cooled the ocean surface waters. By one measure (the surface pressure difference between Darwin and Tahiti), February 2008 was the strongest February La Niña event on record. The last time we had a winter this cool was during 2000-2001, which also happened to be the last time we had a major winter La Niña event.


Figure 1. Departure of temperature from average for the winter of 2007-2008. Image credit: National Climatic Data Center.

A normal winter for the U.S.
December 2007 through February 2008 was about average in the contiguous U.S.--the 54th coolest winter on record in the 113 year period of record. The average temperature was 33.2°F (0.6°C), which was 0.2°F (0.1°C) above the 20th Century mean. It was the 18th wettest December-February in the 1895-2008 record. New York experienced its wettest winter on record, and the states of Colorado, Connecticut, Pennsylvania, and Vermont experienced their second-wettest winter on record. Only the South received below normal levels of precipitation, mostly due to a dry winter in Texas.

All time winter snowfall records have already been set in some portions of the Northeast U.S. and Wisconsin. As of March 12, Madison, WI had accumulated 92 inches of snow, smashing the previous seasonal snowfall record of 76.1 inches (193.3 cm) of snow in the winter of 1978-1979. Two locations in the Northeast have set new winter snowfall records, and more records will fall if an average amount of snow falls in March. By the end of February, new snowfall records for the season-to-date were also set in both Telluride and Aspen, Colorado.

An exceptionally warm winter in Northern Europe and Asia, cold in Central Asia
Northern Asia and northern Europe experienced an exceptionally warm winter, with Sweden and Finland recording their warmest winters ever, and Norway, its second warmest. Conversely, Tajikistan recorded its coldest winter in 30 years, and heavy snows in Kazakhstan caused severe flooding when they melted. Snow storms and cold weather in China this winter killed 129 people and did over $21 billion in damage.

Why did we see a cool winter, if global warming is occurring?
It is important to understand the difference between weather and climate. Climate is what you expect; weather is what you get. What we experience in one particular season or year is "weather". Weather has a large variation from year to year, with cool seasons and years mixed in with warms ones. "Climate" is the weather measured on scales of tens of years or longer. One cool winter or year is not an indication that the climate is cooling back to normal. The climate is warming, and unless we see a series of several years of cool conditions, this year's cool winter merely represents a normal fluctuation of the weather. Relatively cool weather is to be expected globally during a strong La Niña event in the Eastern Pacific Ocean, and relatively warm weather is expected during an El Niño event. We shouldn't expect to see record warmth for the globe unless an El Niño event is occurring.

Why did we see record snows this winter, if global warming is occurring?
Beware of global warming skeptics trumpeting record snowfalls this winter as an excuse to doubt that global warming is occurring. One should primarily look at global temperatures on a scale of decades to judge the validity of global warming. Dr. Ricky Rood, who writes our Climate Change blog, put it this way in his current blog, Creeping Onset of Spring and in an earlier blog, Water, water, water:

This year has been very snowy in the northern hemisphere. That it is snowy does not suggest that it is colder. If it gets warmer, it does not mean that we no longer see freezing temperatures in places like Michigan. If it gets warmer there is more water in the atmosphere, and when there is precipitation there will be more precipitation, and if it is below freezing, then that precipitation will be ice and snow. The high mountains near the coast, like the Cascades and the Sierra Nevada would expect more snow. This is also true for the high altitudes parts of Greenland and Antarctica. From a climate point of view it is more important to look at snow cover in the late winter and early spring. Is the snow melting earlier?


Figure 2. Average February arctic sea ice coverage as observed by satellites between 1979 and 2008. Image credit: National Snow and Ice Data Center

Arctic sea ice recovers a bit
It will be interesting to see if this year's heavy Northern Hemisphere snow cover melts earlier than usual, as this will have a big impact on the annual Arctic sea ice melt. We're starting off with more ice surface area in the Arctic than in the past four years--February 2008 Northern Hemisphere sea ice extent was greater than each of the previous four years, thanks to cooler than usual temperatures over much of the Canadian Arctic. However, this was still the fifth lowest ice extent on record for the month of February, and 8% below its extent in 1979 when satellite measurements began, according to the National Snow and Ice Data Center. February was the third straight month that a new monthly minimum Arctic sea ice record was not set, following a string of five months in a row where monthly records were set. The extra sea ice extent will help to reduce the amount of melting this summer, but this effect will probably be overshadowed by the fact that natural wind patterns have forced a large amount of thick, multi-year ice out of the Arctic this winter. This has left much of the sea ice very thin, making it very vulnerable to melting. For the first time on record, the edge of thin first-year ice has pushed beyond the North Pole. IF we get another relatively warm and sunny summer in the Arctic in 2008, we will likely see Arctic sea ice loss surpassing last year's astounding collapse.

Annual WeatherDance contest ready for registration!
Armchair forecasters, now's your chance to shine! WeatherDance, based on teams in the men's and women's NCAA basketball tournaments, allows players to predict which team's city will be hotter or colder on game day in each round of the Big Dance. Beginning March 17, players can make their forecasts at the Weather Dance Web site at: www.weatherdance.org. The site will be updated with cities promptly after NCAA seeding announcements. Team selection occurs March 16 for men and March 17 for women. First round Weather Dance selections must be entered by 11:59 p.m. EST March 19. Players can register now and receive periodic reminders as the game progresses.

"Officially, Weather Dance began as a class project to get students involved in weather forecasting, but we kept it around because it got popular. People think they can do better forecasting than the meteorologists. Well, here's their shot!" said Perry Samson, WeatherDance creator, co-founder of the The Weather Underground, Inc., and Professor in the Department of Atmospheric, Oceanic and Space Sciences at the University of Michigan.

This is the third year for the game. Last year more than 2,000 people played. Most play merely for the thrill, but many science teachers involve their classes as part of meteorology units. The winning teacher will receive an invitation and $500 to join the Texas Tech/University of Michigan Storm Chasing team this spring for a day of tornado chasing. Other winners will receive a Weather Underground umbrella or a copy of the book "Extreme Weather," by Christopher C. Burt.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 324 - 274

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9Blog Index

323. SickOfDumbQuestions
1:27 AM GMT on March 15, 2008
I do believe we are causing some warming... however I don't believe that we are causing planetary wide warming... for instance we can feel the warming we cause by knocking down trees and putting up a parking lot... I think changes like that would contribute more than any gas we put in the air..

Mathmatically the CO2 raise cannot account for all of the warming that has been happening.. It can only account for a VERY small fraction of a degree...

We are changing the enivroment and some of that will change the temperature, but I think warming is more a cycle of the natural order of things... I think we need to focus on what we can change and that is pollution to our water and oceans. We need to keep the air clean, but we need to focus on the correct areas of pollution.. Co2 isn't an issue.. but smog and acid rain is...

I think alot of people ahve good intentions, but their focus is in the wrong place... we don't need CARBON credits or CARBON controls... we need smog controls and clean air more than anything... we need clean water...

WE do cause environments to warm... go into a forest near a big paved area... its cool in the forest, but hot over the blacktop... thats a man made warming change... we can control small things like that... not the whole climate...

Member Since: Posts: Comments:
322. sebastianjer
9:25 PM EDT on March 14, 2008
lindenii

I am still not sure what you are getting at by pointing to that particular paragraph. I would have to say that particular sentiment is his personal opinion though I happen to agree with it.

In my reading of Pielke over time he has two primary objections against the IPCC et all. Is the over focusing on co2 as a culprit for global warming ignores other natural forcing such as the solar influence, but more importantly fails to take into account other anthropogenic causes, such as land use changes.

His other bugaboo is that to prove something scientifically it must be verifiable. He and others have proposed the litmus test that is that article.

As for myself, I'm pretty simple. First leave the name alone, it's supposed to be global warming, quit muddying the waters with all this climate change nonsense. The theory is in that more CO2 causes more warming, well we are definitely getting more CO2 but...


Graph: HadCRUT 1993-2007


Have a good one
JER
Member Since: Posts: Comments:
320. KoritheMan
1:23 AM GMT on March 15, 2008
@ #318:

Can you say for SURE that humans aren't causing the planet to warm up even a tiny bit? I agree that man has an ego, but it's not illogical to think that we might be warming up the planet some. My personal belief on global warming is that it is a natural cycle that will eventually go away. However, I believe that we are speeding up the warming because of CO2 emissions and the like. Just my take.
Member Since: Posts: Comments:
319. KoritheMan
1:14 AM GMT on March 15, 2008
All I can say is, a LOT of people will be put on my ignore list this year during hurricane season, more than likely anyway. I won't put any of the regulars on my ignore list unless I absolutely have to though, since I know they are smart enough to talk civil and not be biased.

I can't describe just how much I despise when people wishcast, westcast, destructioncast, what have you. What I would like to see is a civil tropics discussion throughout hurricane season this year, from June 1 to November 30. No offense to anyone here who isn't a regular, but surely you guys understand how I feel. The blog was like a madhouse last year.
Member Since: Posts: Comments:
318. SickOfDumbQuestions
12:55 AM GMT on March 15, 2008
I think that humans try to overstate their importance with everything. I think its ignorant to believe because we perceve the planet to be warming that we have to assume that we are the cause of that warming. I read in some post that because something is at the lowest point in recorded history, it must have never been lower. What that person forget is that before HUMAN recorded history we know that there was a land bridge between russia and alaska. So where did all that water come that buried that land bridge??? Thats right, earth warming... So are you telling me that we caused that warming to occur, or is it possible that the weather is on a 100,000 warming cycle that we are not causing?? Have we been warming... sure... but I think man couldn't have caused all of it, or even a little bit... if you do the math of the actual warming potential of the CO2 rise... there is only enough co2 to account for lest than 1/1000th a degree C....

The earth has so many cycles of weather, we humans may not live long enough to ever see a full cycle.

Should be live in a clean earth?? Yes... but I find that the human race has a huge EGO.. and that we must be the cause of all change, epecially if it is BAD change... If we could control or affect the climate on a scale as big as the ENTIRE planet, then we should be able to focus that control and start to actually control small weather systems, like individual storms or hurricanes... and yet we can't do that...

What I also want to know, are humans causing Mars to warm up to?? Mars is warming up as well, and if Earth and Mars are warming, and man is causing Earths warming, isn't it possible that we are causing Mars to warm as well.... or how about we look at the OBVIOUS link... the SUN... I read somewhere that a few other bodies in our system are warming as well....

Man needs to focus on what he can change... we need to keep our environment clean and recycle... we need to preserve our land and keep it clean and pristine... we need to focus on what we know we can change.

If we cannot predict the weather next week, how can we predict what the climate will do?? The modles the so called scientist say predict warming, don't take into consideration solar output, or cloud cover, or cosmic rays that may seed those clouds....

I for one am disappointed in scientists who are drawing certain conclusions from 1/2 the facts... I find Dr. Masters a one sided, egotistical fool who abandond real science and started to interject his opinion based on only some circumstancial evidence. Just because someone could have been there to commit a murder, doesn't mean he did it... because man is on earth doesn't mean he is the cause of everything.... Climate Change is occuring... not of mans influence, but because it has changed for the last 4.5 billion years, and will change until earth doesn't exist. Global warming is a religion.... and Dr. Masters and those who believe we are the cause belong to the radical Islamic jihadists faction of that religion.

Member Since: Posts: Comments:
317. Caffinehog
12:43 AM GMT on March 15, 2008
for example if you reduce data coverage from 4 sq km to 1 sq km you have squared the multiple in terms of data amount...in that case 16 times the data (or 4^2).


I hate to nitpick, but 1 square kilometer is only 4 times as good as 4 square km. 4 square km is 2km x 2km. 1 square km is 1km x 1km.

It's a significant improvement, nonetheless.
Member Since: Posts: Comments:
316. lindenii
7:47 PM EST on March 14, 2008
jer,

I just finished a serious read of the first article and I find myself in love with "joules". Over the years, I have forgotten about "joules" and now that "joules" has gotten play as an opportunity to test the theory of global warming with a non-theoretical test, I find myself overjoyed that "joules" is back in my life.

BTW...I answered my own question on further investigation. Thanks for your original reply.
314. lindenii
7:18 PM EST on March 14, 2008
jer,

The quotation is found in the fourth or fifth paragraph of the first page in the first link you provided in your post #295 "A Litmus Test For Global Warming - A Much Overdue Requirement"

The question really is whether or not the statement is an expression of the authors personal belief or a statement of his interpretation of external activities.

Otherwise, it looks like quite an authentic litmus test indeed.
313. Michfan
11:52 PM GMT on March 14, 2008
Don't forget the Destructioncaster's. We had quite a few of those last season that had to eat some crow. I have a vat of butter on standby for this upcoming season.







=


Member Since: September 7, 2007 Posts: 0 Comments: 1747
312. stormdude77
7:56 PM AST on March 14, 2008
LOL... Pat, I can't until June 1st, to see you're blog...
Member Since: Posts: Comments:
311. stormdude77
7:50 PM AST on March 14, 2008
Good evening, everyone! I hope everyone is well...
Member Since: Posts: Comments:
310. Patrap
6:39 PM CDT on March 14, 2008
Look for my June 1 2008 Blog Entry.
I guarantee you wont be disappointed.

Production iz still in Progress.



Westcaster's and Wishcaster's Beware!

Member Since: July 3, 2005 Posts: 428 Comments: 129902
309. sebastianjer
7:30 PM EDT on March 14, 2008
Sorry lindenii

Just got back from dinner, will check out previous posts. I have no idea what that means since I have not read the paper, and do not know where to look based on your comment. However if you would point me in the right direction I'll read it and give you my opinion if you wish, though I don't know why anyone would want that, lol.

People ought to study all sides of the issue and reach their own conclusions based on their own research into it. Of course if you accept that everything is known and no further investigation is necessary, then everything is known and no further investigation is necessary.

JER

Member Since: Posts: Comments:
308. BahaHurican
7:33 PM EDT on March 14, 2008
Hey Pat,

What kinda trailer is that? What, no stars? No hyped up descriptive teasers?!?!?!

Member Since: Posts: Comments:
307. KEEPEROFTHEGATE (Mod)
11:09 PM GMT on March 14, 2008
and coming it is pat
Member Since: Posts: Comments:
306. lindenii
6:05 PM EST on March 14, 2008
sebastianjer,

I found this comment in one of those same papers.

**********

As discussed on Climate Science and Scitizen (e.g. see and see), the underlying reason for this aggressive campaign to focus on the human emissions of carbon dioxide from fossil fuels as the main culprit is to promote energy policy changes, not to develop an appropriate comprehensive climate policy.

*************

Would you, please, explain this comment to us?
304. Patrap
5:44 PM CDT on March 14, 2008
Coming Soon, to a Gulf or Ocean near you!

"HURRICANE SEASON 2008"

Caution,this film is not yet rated.Parental
Guidance suggested though.
Member Since: July 3, 2005 Posts: 428 Comments: 129902
303. Patrap
5:43 PM CDT on March 14, 2008
Reruns?..where's the phone?
I paid for real time blogging.

LOL
Member Since: July 3, 2005 Posts: 428 Comments: 129902
302. lindenii
5:39 PM EST on March 14, 2008
Think water vapor is not part of the weather equation?

Interesting.

Have you ever used a humidifier in winter to keep the air feeling warmer? I have and it works great. Ever heard of water vapor... heard of carbon dioxide vapor. That is why it is called water VAPOR...get it?

Why is it that live steam carries with it over five times the energy as simple boiling white vapor. Water loves to be in the form of droplets as opposed to water gas...multiple molecules/vapor...single molecules/gas.

Water is a vital part of the greenhouse emissions equations get used to it.
301. Weather456
6:15 PM AST on March 14, 2008
This is just a preview of a typical summer time synopsis of a tropical wave that can be expected this year....

Friday, August 17, 2007, 6:05:02 PM AST

Tropical Atlantic....

Satellite imagery, 315K potential vorticity charts and 700 mb wind analysis through 1800 UTC indicated that a tropical wave is near 31-32W south of 22N. The last visible loops of the day of the Eastern Atlantic clearly depict low-mid level cyclonic turning just to the west of the Cape Verde. This wave continues to be enveloped in very dry African Dust and thus convective active activity remains absent. Another interesting feature is that QuikSCAT shows a second possible circulation within the ITCZ band in the image below.


Friday, July 20, 2007, 1:39:22 PM AST

The tropical wave that entered the Caribbean yesterday is now along 68w south of Puerto Rico moving west near 14 knots. Convection associated with the wave is significantly less than yesterday when it brought between 80 and 140 mm of rain to the leeward islands/virgin islands/Puerto Rico. Convection is now confined to a line of showers in the diffluent flow between the upper low over the nw Caribbean and an upper high in the eastern Caribbean.

Tropical Atlantic....

A well amplified tropical wave continues to transit the tropical Atlantic near 40w-45w south of 18n at 25 knots. The wave continues to produce cyclonic curvatures in both the tradewind flow and stratocumulus cloud fields over the trp Atlantic. Convection remains minimal with this feature due to the very stable environment it is embedded in.

Another possible tropical wave has just exited the African coast with QuikSCAT and streamline analysis hinting a possible low level circulation attached near 9n/13w as of 0600 utc this morning. I'll just have wait for either 12z or 18z nhc analysis for confirmation.
Member Since: Posts: Comments:
299. surfmom
10:00 PM GMT on March 14, 2008
menacing dark clouds, but no rain....the anticipation.........in & out of kitchen
Member Since: Posts: Comments:
298. ouzel
10:00 PM GMT on March 14, 2008
"Beware of global warming skeptics trumpeting record snowfalls this winter as an excuse to doubt that global warming is occurring" - Jeff Masters

"... while we cannot state that the recent widely distributed cold waves or overall cooling of the troposphere are evidence of the end of global warming over decadal and longer time scales" - Roger Pielke Sr.


Well golly gee, Jer, it looks like they agree. As usual, what's your point?
Member Since: Posts: Comments:
297. cchsweatherman
5:56 PM EDT on March 14, 2008
Thoughts on the weather in Florida? Right now, northern Broward and southern Palm Beach counties are under Urban Flood Warnings until 7:00pm EST.
Member Since: Posts: Comments:
296. Weather456
5:56 PM AST on March 14, 2008
Good afternoon to all!

....SYNOPSIS....

GULF OF MEXICO/NORTHWEST ATLANTIC OCEAN WEST OF 50W....

A sharp upper trough continues dig across the Central United States and into Northern Mexico and the Eastern Pacific. Meanwhile, a broad upper ridge is sprawled out over the Caribbean. These two features are producing strong southwesterly winds aloft over the Gulf of Mexico with upper level moisture producing scattered high clouds extending from Southern Mexico, across the Southern Gulf and through the Florida Straits before reaching the Southwest North Atlantic. The most active weather in the Gulf today lies within the northeast portion, including parts of the Southeast and Florida Peninsula, where scattered moderate to strong convection lies north of 27N between 87W and 75W. This area is associated with a surface trough that lies within a favorable jet entrance region upstream of the ridge axis over the Caribbean.

At the surface, a surface trough lies across the Western Gulf extending from Brownsville, TX across the Bay of Campeche and Central America to Honduras at 14N/88W. This feature lies within sinking dry air associated with the upper trough, thereby shower activity remains absent and fair weather exists. The pressure gradient induced by the aforementioned surface trough will allow winds to be southeasterly-southerly at around 10-20 knots, generating seas of 3-4 ft everywhere. Seas should gradually increase to about 6 ft over open waters in southwesterly swells as a cold front advances southward across the Southern United States.

Over the Atlantic, visible imagery showed multilayer cloudiness and showers invading the area west of 60W. Low level convection is spreading from the Gulf to 75W associated with a surface trough being enhanced by upper divergence, and simultaneously these winds aloft are advecting scattered cirrus clouds to about 60W. Visible imagery also showed a 100 nmi line of scattered low clouds associated with a stationary front extending along 30N/70W 25N/60W 27N/50W. Overall winds are expected to be light and variable over most parts due to a weak surface pressure pattern induced by a broad 1020 mb surface high over the area.

CENTRAL AMERICA AND THE CARIBBEAN REGION....

Very strong upper ridging and dry air dominates the entire Caribbean basin. The flow around the ridge is allowing much of the moisture to remain north of the region and along with dry stable air...conditions are expected to remain exceptionally fair and fine at the surface except for Northwestern South America, where the ITCZ/NECZ is producing scattered showers and thunderstorms over Western Venezuela, Colombia and Panama. The broad ridge over the Atlantic continues to maintain a moderate easterly air flow over much of the region. This will cause 3-4 ft easterly swells over the area north of 15N and 5-6 ft south of 15N, peaking at 8ft along the Colombian Coast. For this reason, small craft should exercise caution across the Southern Caribbean Sea.

by W456
Member Since: Posts: Comments:
295. sebastianjer
5:49 PM EDT on March 14, 2008
"Beware of global warming skeptics trumpeting record snowfalls this winter as an excuse to doubt that global warming is occurring" Dr. Jeff Masters

Well golly gee, interesting that a very well respected climatologist actually addressed this issue today from Roger Pielke Sr. Climate Science blog today. Interestingly enough Dr. Pielke does not consider himself a skeptic.
_______________________________________________________
There has been considerable discussion with respect to whether the large number of cold waves and snow this winter in the Northern Hemisphere and last winter in the Southern Hemisphere (e.g. see Dot Earth and the several excellent posts on this subject at Watts Up With That, Climate Audit and ICECAP). They have accurately described this very unusual weather over vast areas of the Earth including the recent sharp cooling in the troposphere. This is clearly climate variability that has not been accurately captured by even the seasonal weather prediction models, much less the longer term global climate models.

Global Warming, of course, is just a subset of the more general issue of climate variability and change. Nonetheless, the political focus has been on global warming using the global average surface temperature trend as the metric.

Climate Science has repeatedly emphasized, however, that the proper way to assess global warming (or cooling) is with diagnoses of global average ocean content; e.g. see

A Litmus Test For Global Warming - A Much Overdue Requirement

Important New Paper In Press by Willis And Colleagues On Sea Level Rise And Ocean Heat Content Changes


The recent cooling in the atmosphere does not demonstrate that global warming has stopped for multi-year time periods. It does, however, highlight a major failing in that the multi-decadal global model predictions (and even the seasonal weather prediction models) have predicted no such behavior.

Moreover, as reported on Climate Science, global warming requires a more-or-less monotonic increase in the accumulation of heat (in Joules) within the climate system. The use of a global average surface temperature, regardless if it is increasing or decreasing is an inadequate and inaccurate metric of global warming as the heat is not only a function of temperature but also mass over which the heat change occurs! This is why the ocean is the dominate reservoir of heat content change.

With respect to the change in upper ocean heat content, as reported on a Climate Science weblog on February 15 2008, the paper

Willis, J. K., D. P. Chambers and R. Steven Nerem, 2008: Assessing the Globally Averaged Sea Level Budget on Seasonal and Interannual Time Scales. Journal of Geophysical Research-Oceans (in press),

reports on no upper (700m) ocean warming since 2004.

Thus while we cannot state that the recent widely distributed cold waves or overall cooling of the troposphere are evidence of the end of global warming over decadal and longer time scales, we can state that global warming has not occurred in the last 4 years. This is a major issue for both climate science and for policymakers, as only those who blindly (or deliberately) ignore the scientific evidence can still accept the 2007 IPCC conclusions as settled science.

_________________________________________________

I for one will continue to beware
Member Since: Posts: Comments:
294. franck
9:28 PM GMT on March 14, 2008
What temps!
Folks in Montgomery, AL last year had half the days of August from 105 to 113 degrees.
Wear them A/C compressors out!!!
Member Since: August 30, 2005 Posts: 0 Comments: 1150
292. gippgig
9:12 PM GMT on March 14, 2008
How likely is it that by the end of summer the north pole will be ice free?
Member Since: Posts: Comments:
291. lindenii
4:11 PM EST on March 14, 2008
atmoaggie

Hmmm.

I have an area 9 km2. Can't that area be described as a square 3 km x 3 km? 3x3=9 ?

So, how is it that a 1 km2 doesn't go like this. 1 km x 1 km = 1 km2 which, I thought would mean that you would have 9 of those pixels and therefore 9 times the data.

Errr. I just figured it out. I was refering to a pixel, as you call it, as being 3x3 and you thought 9x9.

Okay, so if you average the data, would you simple add each of the relative data points together and divide by 9?

Assuming that is the correct view of the data...What happens if the data collected also has a different number of significant digits as well. In order to compare data collected using a fewer number of significant digits wouldn't also be more accurate to, as I mentioned earlier, lope off the excess digits without rounding so that the data would more replicate the data with less significant digits?
290. AWeatherLover
9:11 PM GMT on March 14, 2008
The stronger storms look like they are finally beginning to come ashore in Pinellas, whereas before they were dissipating once they got near the coast.
Member Since: Posts: Comments:
289. AWeatherLover
9:09 PM GMT on March 14, 2008
Thanks Adrian. You've got mail.
Member Since: Posts: Comments:
288. BahaHurican
4:40 PM EDT on March 14, 2008
Afternoon, everybody. I'm looking at that line of weather headed this way, and it does look like the worst of it, the off shore part, is losing some strength. Anybody thinks it's likely to build up again overnight?
Member Since: Posts: Comments:
287. cchsweatherman
4:37 PM EDT on March 14, 2008
Based upon the latest radar, the bow-echo noted just about a half-an-hour ago has lost steam and has just become a vertical line segment. It seems like the storms may have started to lose energy as showers and storms have begun developing over South and Central Florida ahead of the convective mass.
Member Since: Posts: Comments:
286. hurricane23
4:33 PM EDT on March 14, 2008
259. AWeatherLover 3:44 PM EDT on March 14, 2008
Hey Adrian, how is that research on La Nina going? Also, any idea about west central FL? I nosted someone already posted this, but it seems that the storms die off as soon as they get to the coast. Are we gonna get some actual rain?

Check your mail!
Member Since: Posts: Comments:
285. atmoaggie
8:22 PM GMT on March 14, 2008
Re 236.

1 km^2 data is 81 times the data from 9 km^2

for example if you reduce data coverage from 4 sq km to 1 sq km you have squared the multiple in terms of data amount...in that case 16 times the data (or 4^2).

As for resampling, that can be done a number of ways, all with pros and cons.
1. Simple nearest lat/long value of the high res data to the center of the low res data. Simple, but could introduce error. This assumes that the center pixel would fully respresent what the coarser system can "see".

2. Resample via averaging all "pixels" of the higher res data within a distance of the center. This assumes all pixels in 1 km set are "seen" in a single 9km pixel.
3. Conduct a weighted average. Pixels further from center get less consideration, but are not neglected completely. This is likely the best to use, but is the most computationally intensive.
4. ...there are more that I do not have time for at the moment that involve a lot of ugly statistics

Lastly, a lot depends on detection and removal of contaminants. There are current signals in SST measurements that come from high, thin clouds that get through automated masking and end up in the data.

The result is an oddly cool pixel surrounded by warmer ones in a relative sense (I am talking tenths of a degree C here). There is no physical explaination outside of very small scale upwelling, which can be and is accounted for via wind records and bathymetry/current work. These slightly contaminated pixels have existed in every satellite SST source. What does that statement mean for trends? I dunno.
Member Since: August 16, 2007 Posts: 6 Comments: 12463
284. Patrap
3:06 PM CDT on March 14, 2008



SPC Short Range Ensemble Forecast (SREF) Page
Click on desired model run (format: YYYYMMDDHHz) Link


Overview
The SPC Short-Range Ensemble Forecast (SREF) is constructed by post-processing all 21 members of the NCEP SREF plus the 3-hour time lagged, operational WRF-NAM (for a total of 22 members) each 6 hours (03, 09, 15, and 21 UTC). Output is available at 3h intervals through 87 hours. The SPC ensemble post-processing focuses on diagnostics relevant to the prediction of SPC mission-critical high-impact, mesoscale weather including: thunderstorms and severe thunderstorms, large scale critical fire weather conditions, and mesoscale areas of hazardous winter weather. Presentation of the SREF output via this WEB portal is similar to its presentation at the SPC within the N-AWIPS operational display system. All SREF information presented herein is for guidance purposes only and remains under development. This ensemble guidance should not be mistaken for or used in lieu of operational SPC products and forecasts.
Member Since: July 3, 2005 Posts: 428 Comments: 129902
283. surfmom
8:07 PM GMT on March 14, 2008
Off to be domestic
Member Since: Posts: Comments:
282. AWeatherLover
8:02 PM GMT on March 14, 2008
I get you surfmom. It sure looks like its panning out. Already have some of it built. I've kept up with it for years now. I don't know if anything is as good as getting out there on a great day and catching that awesome ride. But I think this will be great for those very long flat spells we get on the gulf coast. I may not be old but I'm not one for terror either.
Member Since: Posts: Comments:
281. surfmom
8:03 PM GMT on March 14, 2008
cchs, thnx for the update...sounds good for me rain at night, dry by the 1:00 polo game my son is playing in. Prefer, pray for dry footing, don't want any slip & slip w/the horses
Member Since: Posts: Comments:
278. HIEXPRESS
3:54 PM EDT on March 14, 2008
264. StormW 3:49 PM
Nice bow echo about 100 miles SW (248 deg.) of Tampa.

Yes, that would be the upper air reflection of just getting my new boat registered & filled with fuel.

I guess I should start loading it 2X2.
Member Since: Posts: Comments:
277. surfmom
8:03 PM GMT on March 14, 2008
Hey Storm - LOVED the gasoline hum our this AM
Member Since: Posts: Comments:
276. AWeatherLover
8:00 PM GMT on March 14, 2008
Thanks! I don't know if I'm missing it, but I don't see LFC. Is it under a different term?
Member Since: Posts: Comments:
275. surfmom
7:58 PM GMT on March 14, 2008
It would be nice if the Ron Jon thing panned out....but could it really be as good? Besides I never would have given a hoot about weather if I wasn't so dependent opn it as a wave maker. I have learned so much and now really love watching whats going on. The importance of weather is so crucial --economically, socially etc......I find that since I have hook in here, I am always alerted for any window of opportunity and I usually have enough notice to plan and sneak it in. 4-footers are lovely, I am a long boarder, very light --so I get great rides without terror. Too old for the terror.
Member Since: Posts: Comments:
274. cchsweatherman
3:54 PM EDT on March 14, 2008
Good afternoon all! Starting to feel better now, but still will not post my report supporting my hurricane season predictions posted on my site.

Based upon radar and satellite analysis, it looks like there may be a rapid change in the forecast for Central and Southern Florida tonight as a strong convective complex has developed throughout the day in the Eastern GOM. It continues moving towards the SE at a rather quick clip. I have begun to notice a strong bow-echo forming about 100 miles west of Tampa. This will have to be watched during the next few hours to see if it maintains itself while approaching the coast. What appears to be a weak trough has developed across South Florida in a near horizontal line with the southern tip of Lake Okeechobee as some heavy showers and isolated storms have started to build. Things look much more conducive for showers and storms in South Florida than earlier. Notice that instability has increased over the entire area, but we all know that a good gust front can immediately stabilize the atmosphere. All in all, looks like Central Florida including the Lake (which currently stands at 10.16 feet) should get some nice soaking rains into the night, but I do not anticipate much heavy rain for South Florida as the complex should lose steam by then.
Member Since: Posts: Comments:

Viewing: 324 - 274

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

Local Weather

Overcast
37 °F
Overcast

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron