WunderBlog Archive » Category 6™

Category 6 has moved! See the latest from Dr. Jeff Masters and Bob Henson here.

Record-Strength Upper Low Brings Extreme Rains to South U.S., Thundersnow to Mexico

By: Bob Henson and Jeff Masters 4:51 PM GMT on March 10, 2016

A remarkably rare atmospheric event is unfolding over Mexico and the Southern U.S., where an upper-level low pressure system of unprecedented strength in the historical record for that location has stalled out, bringing multiple days of torrential rain to the Southern U.S. and snow to the mountains of Mexico. The upper low tapped into an atmospheric river of moisture from both the Western Caribbean and the Eastern Pacific, bringing rainfall amounts one would expect to occur only once every 200 years (a 0.5% chance of occurrence in a given year) over portions of northern Louisiana. According to the latest NOAA Storm Summary, as of 9 am EST Thursday, the city of Monroe, Louisiana had received 17.25" of rain since Monday, and Shreveport had picked up 16.70" at Barksdale Air Force Base. The heavy rains led to numerous high water rescues, evacuation of at least 3,500 homes, and closures of hundreds of roads. Portions of two interstate highways in northern Louisiana--I-20 and I-49--were closed on Thursday morning due to flooding, according to KSLA.com. Three drownings have been reported since Monday from the storm system--one each in Texas, Oklahoma and Louisiana.


Figure 1. Flood damage in Haughton, Louisiana, on March 9, 2016. Thirty homes near Haughton were inundated by flood waters on Tuesday night, forcing evacuations. Image credit: Michael Dean Newman.


Figure 2. A webcam from Zacatecas, Mexico, catches snow falling on Wednesday, March 9, 2016. Thundersnow was reported at the city’s official reporting site. Image credit: webcamsdemexico.com, courtesy Eric Blake.


Figure 3. Observed 48-hour precipitation for the period ending at 10 am EST Thursday, March 10, 2016. Portions of northern Louisiana received over 16" of rain, and a large area of 8+" fell over portions of Eastern Texas, Northern Louisiana, Southeast Arkansas and Northwest Mississippi. Image credit: NOAA/NWS.


Figure 4. Average recurrence interval in years for the 24-hour rainfall amounts that fell ending at 7 am EST Wednesday, March 9, 2016. Rainfall amounts one would expect to occur only once every 200 years (a 0.5% chance of occurrence in a given year) fell over some portions of northern Louisiana just east of Shreveport. MetStat computed the recurrence interval statistics based on gauge-adjusted radar precipitation and frequency estimates from NOAA Atlas 14 Volume 8, published in 2013 (http://dipper.nws.noaa.gov/hdsc/pfds/.) The real-time analysis (observed) can be monitored for free at: http://metstat.com/solutions/extreme-precipitation-index-analysis/ or on their Facebook page.  MetStat also offers a subscription for precipitation interval forecasts and analyses at http://metstat.com/solutions/extreme-precipitation-index-forecasts/


Figure 5. The Bayou Dorcheat at Lake Bistineau, Louisiana reached its highest water level on record Thursday morning. The extreme rains in northern Louisiana have poured into local lakes and rivers, sending a few close to or in excess of their highest water levels on record. On Friday, the Sabine River near Burkeville is predicted to exceed its highest crest since 1884. Image credit: NOAA.

Weather weirding par excellence: Strongest upper low ever observed over central Mexico?
This upper low originated from energy that moved across southern California late in the weekend, producing heavy thunderstorms. Rather than barreling across the southeast U.S., the powerful subtropical jet stream carved out a progressively deeper trough into Mexico that cut off from the jet stream, forming a slow-moving closed low. At 00Z (7:00 pm EST) Thursday, this cold-cored upper low was centered in central Mexico, roughly in the vicinity of Guadalajara. Thundersnow was reported on Wednesday in Mexico at Zacatecas (altitude 8010 feet), about 200 miles north of Guadalajara. However, weather records researcher Maximiliano Herrera told us in an email that snow in the mountains of northern Mexico has occurred in April, May and even early June, so is not that unusual. As shown in Figure 7 below, this upper low featured a large 558-decameter contour (the 558 dm, which is 5580 meters, refers to the height at which the atmospheric pressure is 500 mb, or about half of the typical surface pressure). Such a large, strong upper low appears to be an unprecedented event in modern weather observations for Mexico; upper-air analyses dating back to 1948 from the NCEP/NCAR reanalysis project suggest that no previous upper low in this region has been strong enough to generate a 558-dm contour. During the last “super” El Niño, in mid-December 1997, a powerful upper trough extended south from the United States, producing what was reportedly the first snow observed at Guadalajara since February 1881. Low-level temperatures have not been quite as cold this time around, given that it’s now early March rather than mid-December, but the thundersnow reported at Zacatecas indicates the strong instability being produced by the deep cold at upper levels. The gradient between this upper low and a strong upper ridge over the eastern U.S. has also intensified the southerly flow pumping moisture into the south-central states.


Figure 6. GOES satellite imagery from 0245Z Thursday, March 10, 2016 (9:30 pm EST Wednesday), shows the immense swirl of an upper-level low centered over central Mexico, as well as the stream of moisture extending from the waters of the eastern tropical Pacific (still warmed by El Niño) across the western Gulf of Mexico into Texas and Louisiana. Image credit: NASA Earth Science Office and NOAA.


Figure 7. 500-mb map for 00Z (7:00 pm EST) Thursday, March 10, 2016, as initialized in the GFS model. Image credit: NOAA/NCEP.


Figure 8. 500-mb map for 12Z (7:00 am EST) Friday, December 12, 1997, about the time that the upper trough had reached its maximum extent into Mexico. Image credit: NOAA Daily Weather Map.

Premature spring warmth swaddles Northeast
Dozens of temperature records melted like so much gelato beneath sun-filled skies across much of the Northeast on Wednesday. Boston basked in temperatures that topped out at 77°F--not just a daily record, but the city’s warmest official reading on any day in astronomical winter since records began there in 1872. New York City’s Central Park also had its earliest 77°F in records that, likewise, go back to 1872. The uncannily mild air served as a fitting curtain call after New England’s warmest meteorological winter on record (Dec-Feb). The lack of persistent snow cover across New York and New England helped give this week’s warmth an extra boost. Some of the records set on Wednesday, March 9, 2016 included:

Earliest 80°F on record
Albany, NY:  81°F (previous record March 16, 1990)
Hartford, CT: 81°F (previous record March 20, 1945)
Newark, NJ: 82°F (previous record March 13, 1990)Poughkeepsie, NY: 82°F (previous record March 13, 1990)

Earliest 75°F on record
Boston, MA: 77°F (previous record March 14, 1946)
Concord, NH: 77°F (previous record March 18, 2012)

Earliest 70°F on record
Glens Falls, NY 77°F (previous record March 13, 1990)

Earliest 65°F on record
Montpelier, VT: 66°F (previous record March 15, 1990)
St. Johnsbury, VT: 65°F (previous record March 16, 1990)


Figure 9. Spring fever sweeps across the campus of Columbia University in New York City on Wednesday, March 9. Image credit: Bob Henson.

The forecast: more flooding in the South, more warmth for the East
Looking ahead, the atmospheric river of moisture responsible for this week's heavy rains has shifted slightly eastwards, and was still at near-record levels in excess of 200% of normal on Thursday morning. The 12Z Thursday morning balloon sounding at Lake Charles, Louisiana showed an astonishing 2.15" of precipitable water in the atmosphere--the second highest value on record for the months of December - April (thanks go to Peter Mullinax, ‏@wxmvpete, for this stat.) This moisture will continue to feed torrential rains over Louisiana, Arkansas and Mississippi on Thursday and Friday.


Figure 10. Predicted precipitation for the 3-day period ending 7 am EST Sunday, March 13, 2016. Heavy rains in excess of 7" (brown colors) are expected over eastern Louisiana, including New Orleans. Image credit: National Weather Service.

A solid week of unusually mild air lies in store for most of the nation east of the Rockies. Though we can expect dozens if not hundreds of daily record highs to be set between now and then, it looks highly unlikely this mild spell will dislodge the Great Warm Wave of March 2012 from its place of pride in our late-winter/early-spring climate annals. That phenomenal stretch of warmth brought close to a week of temperatures topping 80°F from the Midwest to the Northeast. The town of Lapeer, Michigan, hit 90°F on March 21 (setting a state record for March). Readings that would have broken records for April, much less March, extended into the Canadian Maritimes.



Video 1. Drone footage of flooding in Bossier City in Northern Louisiana on March 9, 2016. Thanks go to wunderground member Skyepony for posting this video in the blog comments.

Bob Henson and Jeff Masters
Wallace Lake Road Shreveport Louisiana
Wallace Lake Road Shreveport Louisiana
Wallace Lake Road Shreveport Louisiana

Flood

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

Euro Weeklies are showing that same kind of upper trough across the SE US come early April. Looks like March came in like a Lamb and is set to go out like a roaring Lion.
Over 500 people now being sheltered by the Red Cross in Louisiana.


I wouldn't describe 3500 flooded Homes in Louisiana, as March "coming in like a Lamb".

Not at all.

I kept wondering if and how much snow they were getting in the mountains of Mexico from this system?
Quoting 3. Sfloridacat5:

I kept wondering if and how much snow they were getting in the mountains of Mexico from this system?


Over 2' across some of the higher peaks in Central Mexico.
I've received 2.96" out of this event so far where I'm at between Houston and Galveston. Pales in comparison to 17" that others received, I'm lucky.

Thanks for update! It is raining cats and dogs here in Memphis!
Still no sign of a reversal to these wind anomalies across the Central & Eastern Pacific. Not a WWB but weaker than normal easterlies. Not what one would expect when saying that a complete reversal to La-Nina is coming. I think JB needs to look further than just the upcoming SOI rise.

From the Servicio Meteorológico Nacional in Mexico

WARNING: POTENTIAL snow or sleet AND STRONG WINDS IN MOUNTAIN AREAS NORTH, NORTHEAST, CENTRAL AND EAST OCCIDENTEM COUNTRY AND HEAVY RAINS IN TIMELY Coahuila, Nuevo Leon, Tamaulipas, Durango, Zacatecas, Veracruz and Oaxaca DURING THE NEXT 3 HOURS.
This Cold Pool across the North Atlantic could a have a negative impact on this years Hurricane Season as Warmer anomalies set up near 30N while the cooler anomalies set up across the MDR. Not looking like a Active Hurricane Season if you ask me.

Oddly enough, I lived in West Central LA during TS Allison (89) and in HTX during the well-known TS Allison in 2001. Both happened in June and there was some warning for each, although both held surprises far beyond what we expected.

It's hard to grasp just how much water is in this early March rainfall, and it's hard to think of it as a non-tropical storm event. I checked in with the few people I still know down in Bossier City. At least they purchased lots on the high-ground and are good for now.

Near Sabine River and Toledo Bend, Lake has reached 3rd highest at 173.76ft before massive release. Reports stating that lake pool is rising again after a 1.5ft fall as a result of the large release this morning. Lake pool is not stabilized and additional gate increases are imminent to attempt to slow the pool rise and reduce pressure against the dam.
It will happen.
At least Wallace LAKE Road is named appropriately...

I hope the flooding subsides and doesn't get worse. Prayers to those that have lost their homes. I do know what it all feels like and it stinks. Takes years to get back to normal too.
The rain is on the move today. We haven't seen a lot of that the past couple days.
Bow echo pushing east
Quoting 9. StormTrackerScott:

This Cold Pool across the North Atlantic could a have a negative impact on this years Hurricane Season as Warmer anomalies set up near 30N while the cooler anomalies set up across the MDR. Not looking like a Active Hurricane Season if you ask me.


I don't think we will have and active season but things can still change very fast like in 2013.
All it takes is one to mess up your 'season'.
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.
FLASH FLOOD WARNING MEMPHIS TN - KMEG 1113 AM CST THU MAR 10 2016
FLASH FLOOD WARNING JACKSON MS - KJAN 1113 AM CST THU MAR 10 2016
FLASH FLOOD WARNING SHREVEPORT LA - KSHV 1100 AM CST THU MAR 10 2016
SVR T-STORM WARNING JACKSON MS - KJAN 1059 AM CST THU MAR 10 2016
SVR T-STORM WARNING JACKSON MS - KJAN 1056 AM CST THU MAR 10 2016
FLASH FLOOD WARNING MEMPHIS TN - KMEG 1044 AM CST THU MAR 10 2016
SVR T-STORM WARNING JACKSON MS - KJAN 1006 AM CST THU MAR 10 2016
FLASH FLOOD WARNING SHREVEPORT LA - KSHV 838 AM CST THU MAR 10 2016
FLASH FLOOD WARNING SHREVEPORT LA - KSHV 944 AM CST THU MAR 10 2016
FLASH FLOOD WARNING JACKSON MS - KJAN 938 AM CST THU MAR 10 2016
SVR T-STORM WARNING JACKSON MS - KJAN 936 AM CST THU MAR 10 2016
FLASH FLOOD WARNING SHREVEPORT LA - KSHV 931 AM CST THU MAR 10 2016
FLASH FLOOD WARNING JACKSON MS - KJAN 921 AM CST THU MAR 10 2016
FLASH FLOOD WARNING JACKSON MS - KJAN 913 AM CST THU MAR 10 2016
FLASH FLOOD WARNING SHREVEPORT LA - KSHV 908 AM CST THU MAR 10 2016
FLASH FLOOD WARNING LAKE CHARLES LA - KLCH 901 AM CST THU MAR 10 2016
FLASH FLOOD WARNING JACKSON MS - KJAN 854 AM CST THU MAR 10 2016
FLASH FLOOD WARNING JACKSON MS - KJAN 844 AM CST THU MAR 10 2016
FLASH FLOOD WARNING SHREVEPORT LA - KSHV 838 AM CST THU MAR 10 2016



Precipitation forcast for Acme, Wa was a bust, only .25". However the wind has been intense. 64mph gust at Bellingham int airport. Power is out all over. Had to make coffee on the wood stove.

We're off to Baton Rouge up I-10 shortly.


Looking awful gloomy to the West currently.

Getting our first notable showers in Baton Rouge starting about 15 minutes ago. Forecasting 4-5" in our area over the next 3 days right now.
Quoting 24. Patrap:

We're off to Baton Rouge up I-10 shortly.


Looking awful gloomy to the West currently.




Careful during your travels, Pat. Some pretty strong cells with heavy rain coming through the area right now.
Michael Ventrice ‏@MJVentrice 2 hHace 2 horas
Latest CanSIPS model showing a VERY favorable tropical atmospheric state for the 2016 Atlantic Hurricane Season.
Mt Baker ski area reporting 109mph wind gust on top of panorama dome! 12" of new snow but they are closed.
Quoting 27. Gearsts:

Michael Ventrice ‏@MJVentrice 2 hHace 2 horas
Latest CanSIPS model showing a VERY favorable tropical atmospheric state for the 2016 Atlantic Hurricane Season.


sst compare maps 1 of many aspects


Thank You Dr. Masters and Mr. Henson; here is the current relative location of the low and related jet displacement. Amazing and thank you both for breaking down the specifics and historical context.  Sad to see that the moisture plume streaming up from the E-Pac/Central America keeps on getting thicker over the past several hours as it moves North into the Southern Gulf of Mexico.




Thankfully, the waters in the Western Gomex are still relatively cool or else we might be seeing some baroclinic convection in the Gulf:


Quoting 18. Gearsts:

I don't think we will have and active season but things can still change very fast like in 2013.


Its a tough forecast maybe the toughest we've ever seen. Models showing La-Nina others showing neutral and 2 showing El-Nino. Then you have a weird sea surface temp set up across the Atlantic. Strange.
Never seen an ULL this far south into MX spinning, besides a tropical system which is different.

Something has always nagged me about upper lows...why are they cold? Are they simply collection areas that develop in the upper air for air cooled by high altitude radiation to space?
Capital Weather Gang ‏@capitalweather 2m2 minutes ago
Dulles and BWI broke their records for today. DCA catching up.

It is currently 81 degrees at my house and I see a leaf popping out on my some of my bushes.

Capital Weather Gang ‏@capitalweather 42m42 minutes ago
Warning to visitors, Yellowstone grizzly bears emerge weeks early due to warm weather
Link
vis. satellite only goes back 50 yrs or so so who knows the last time we have had a ull like this.
EL NIÑO/SOUTHERN OSCILLATION (ENSO)
DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
and the International Research Institute for Climate and Society
10 March 2016

ENSO Alert System Status: El Niño Advisory

Synopsis: "A transition to ENSO-neutral is likely during late Northern Hemisphere spring or early summer 2016, with close to a 50 percent chance for La Niña conditions to develop by the fall."

So, still not a slam dunk for La Nina, but likely for "neutral".

Quoting 30. weathermanwannabe:

Thank You Dr. Masters and Mr. Henson; here is the current relative location of the low and related jet displacement. Amazing and thank you both for breaking down the specifics and historical context.  Sad to see that the moisture plume streaming up from the E-Pac/Central America keeps on getting thicker over the past several hours as it moves North into the Southern Gulf of Mexico.






This unusual pattern is blocking the Pacific jet and associated systems from moving on past California which is causing a somewhat stagnant front to drop constant rain over northern Cal, with the frontal zone drifting ever so slightly southward into the Bay Area. Flood warnings are up in the north Bay valleys like Napa and Sonoma. The grapes won't be thristy this year. The northern Sierra is also getting a heavy soaking.
Quoting 34. BayFog:

Something has always nagged me about upper lows...why are they cold? Are they simply collection areas that develop in the upper air for air cooled by high altitude radiation to space?


They are cold because air cools fairly rapidly as you go up (think of the frost on the window pane of your passenger plane flying at 30,000 ft) so an upper level low is normally very cold compared to the air closer to the surface (whether the land or the oceans). These ULL's (because cold air sinks down) usually drop cooler air down on their periphery and when this cooler air meets the warmer air at the surface, convection (and certainly clouds) can also form. Think of an old school refridgerator (with the freezer in the top part) and you open the freezer door when it is hot in your kitchen; instant "fog-condensation" as the cool air spills out and meets the warmer air mass.
Quoting 34. BayFog:

Something has always nagged me about upper lows...why are they cold? Are they simply collection areas that develop in the upper air for air cooled by high altitude radiation to space?



Surface lows exhibit low pressure because there is slightly less total mass in the column overhead (they are the result of net divergence). They tend to have convergence at lower levels, divergence at upper levels and net upward motion, hence unsettled and overall more cloudy conditions.


However upper lows have an additional large term. Cold air is denser than warm air and pressure is hydrostatic (to a very close approximation) so pressure decreases faster with height in a cold air mass. Therefore at a given significant height with the same total mass in the column, pressure will be lower in a cold air mass than in a warm air mass. Above about 15K feet the temperature term overwhelmingly dominates so low pressure that high up usually means a cold air mass underneath.
Quoting 14. Gearsts:

It will happen.



That's 384 hours out. You might as well take random water colors and throw them at a paper map. :P
40. georgevandenberghe
2:29 PM EST on March 10, 2016

His explanation is much better than my 3rd Grade Science Project Kitchen Experiment.........................
Quoting 41. Xyrus2000:



That's 384 hours out. You might as well take random water colors and throw them at a paper map. :P


Ensembles still show skill this far out especially if they are consistent over several cycles. I'm buying a significant cooldown in the East NEXT weekend from the GFS.. a warmup like this.. remains to be seen. The GFS started picking up on our current warm period about Feb 28 or so and after a few runs I started thinking it would happen.
Quoting 33. RitaEvac:

Never seen an ULL this far south into MX spinning, besides a tropical system which is different.




The problem isn't necessarily the ULL, it's the fact that it has been basically stationary for days. We see a lot of ULL during the hurricane season, but they are usually moving east to west into Mexico.
The ULL is in the perfect position (basically not moving) to pull moisture from deep in the tropics and the GOM into the Gulf Coast.
46. vis0
(repeat from last Dr/ Masters'/Mr. Henson' s blogbytes last pg)
20N 60W (NNE of the top of the Lesser Antilles) not a not deal as to
any TS (though for the islands recuperating from last years flood keep
an eye out) but so Grothar can practice Grothar's blobetics
Quoting 41. Xyrus2000:



That's 384 hours out. You might as well take random water colors and throw them at a paper map. :P
lol yep
The big question now I think is when is the stalled ULL expected to gain some momentum/move out of Mexico and keep pushing East at a faster clip.............................
Recurrence interval calculation based on recent climate period and includes increased precipitation from global warming. Calculating the the recurrence interval from earlier climate periods (e.g., 1931 - 1960, before the recent surge in AGW) would remind us that this is truly bizarre weather for March.
I'd wait until May-June before trying to predict what will happen this Hurricane Season. As we saw last season, SSTs can change rather rapidly. The MDR warmed rapidly from September to October. Thankfully El Nino induced a lot of shear across the Atlantic (record breaking at times), otherwise we could've been looking at a monster season with the tropical waves being very rigorous as well.

This year will certainly be interesting as it has the most potential since 2010 to be an active season.

Quoting 50. Envoirment:

I'd wait until May-June before trying to predict what will happen this Hurricane Season. As we saw last season, SSTs can change rather rapidly. The MDR warmed rapidly from September to October. Thankfully El Nino induced a lot of shear across the Atlantic (record breaking at times), otherwise we could've been looking at a monster season with the tropical waves being very rigorous as well.

This year will certainly be interesting as it has the most potential since 2010 to be an active season.


I was about to make a comment on the tropical waves as well.If the tropical waves are anything like the ones last year then I don't see why we can't have at least a average hurricane season.The waves were very strong and resilient in 2015 which is probably why we saw a more active MDR than what many people were predicting.I saw some climate models predicting a wet Sahara so its something to look out for.
Have no idea whether Arctic warming issues are related to this huge current kink in the jet (as opposed to the very strong ULL that displaced it) but found this article (quoting Dr. Masters) on TWC site................An interesting read at the moment as we are looking at the stalled low over Mexico:

https://weather.com/news/news/heat-wave-alaska-je t-stream-may-be-blame-20130625

A sample paragraph from this article:

The jet stream is about 14 percent slower in the fall now than in the 1990s, according to a recent study by Francis. And when it slows, it moves north-south instead of east-west, bringing more unusual weather, creating blocking patterns and cutoff lows that are associated with weird weather, the Rutgers scientist said.
Quoting 52. washingtonian115:

I was about to make a comment on the tropical waves as well.If the tropical waves are anything like the ones last year then I don't see why we can't have at least a average hurricane season.The waves were very strong and resilient in 2015 which is probably why we saw a more active MDR than what many people were predicting.I saw some climate models predicting a wet Sahara so its something to look out for.


The potential is there for an active season if the conditions fall into place. We should get at least near average. I'm not sure how active the MDR will be, but we should keep an eye on the Western Atlantic and GOM, which are expected to have above-average SSTs and below-normal wind shear. Even 2005 didn't have all that much MDR activity; I think there was only one hurricane in the region.
Quoting 7. StormTrackerScott:

Still no sign of a reversal to these wind anomalies across the Central & Eastern Pacific. Not a WWB but weaker than normal easterlies. Not what one would expect when saying that a complete reversal to La-Nina is coming. I think JB needs to look further than just the upcoming SOI rise.




the SOI rise is not upcoming...although jb as a professional is talking about the 30 day running average......the daily...which some people love to quote here....has been either in the neutral or nina range for a week now
I find it odd how the CFS predicts yet another Very Strong El Nino, yet it predicts well below-normal wind shear in the Gulf of Mexico September and October. Doesn't make a lot of sense, and I wouldn't trust this model until the initialization errors are fixed.

Euro and its ensembles are showing a lot of rain across FL starting later next week and could last for several days. Moisture could get tapped from the E-Pac and sent across the Eastern Gulf/FL. Boy could use a wet change around here as it has been very dry the last 2 weeks in FL and now its getting very warm with temps in the mid to upper 80's so the drying process is speeding up with each passing day.
Quoting 43. georgevandenberghe:
Ensembles still show skill this far out especially if they are consistent over several cycles. I'm buying a significant cooldown in the East NEXT weekend from the GFS.. a warmup like this.. remains to be seen. The GFS started picking up on our current warm period about Feb 28 or so and after a few runs I started thinking it would happen.
And all this time I thought they ran them out that far just to heat the building. The horror! :-O
Quoting 54. HurricaneFan:



The potential is there for an active season if the conditions fall into place. We should get at least near average. I'm not sure how active the MDR will be, but we should keep an eye on the Western Atlantic and GOM, which are expected to have above-average SSTs and below-normal wind shear. Even 2005 didn't have all that much MDR activity; I think there was only one hurricane in the region.
Shear was below average in the caribbean for January standards.Now as to if that signifies or foreshadows something later down the road we have to see if it continues.The caribbean has been hostile for tropical cyclone formation for sometime now with either fast trades or very high wind shear.
well wash enjoy the warmth
cool wetness is coming for a quick visit
then the return for the above normal warmth after that

Quoting 57. HurricaneFan:

I find it odd how the CFS predicts yet another Very Strong El Nino, yet it predicts well below-normal wind shear in the Gulf of Mexico September and October. Doesn't make a lot of sense, and I wouldn't trust this model until the initialization errors are fixed.




well....if considering which, if any, od the cfs models to trust...consider that the 3.4 initialization has been off for quite some time now....
temps will fall to near freeze marks late tonight for me but then rebound back into the 60's on the weekend
Quoting 57. HurricaneFan:

I find it odd how the CFS predicts yet another Very Strong El Nino, yet it predicts well below-normal wind shear in the Gulf of Mexico September and October. Doesn't make a lot of sense, and I wouldn't trust this model until the initialization errors are fixed.


CFS also showing fast trades.
Quoting 63. ricderr:



well....if considering which, if any, od the cfs models to trust...consider that the 3.4 initialization has been off for quite some time now....
I thought the issue was the Atlantic La nina the CFS is showing since January.
On the cooler snap out several days, it would seem to be in that area south of Alaska moving to the East but how deep (into the US) it gets remains to be seen by the time it gets here (in what relative configuration in a few days): this also highlights how much the Mexican low has displaced the normal flow of the jet over Conus.



Quoting 59. bappit:

And all this time I thought they ran them out that far just to heat the building. The horror! :-O
LOL!
Meh, above or below average SSTs don't mean that much if shear is howling and there's a complete lack of vertical instability in the Atlantic again. 2015 was an El Nino and still produced a borderline Category 5 hurricane that hit the Bahamas.
What affect will this have on the control structures of the Mississippi? Ever since the Red river nearly took the main flow i have been watching and waiting for the day that nature moves the river where she wants to flow.
Quoting 40. georgevandenberghe:




Surface lows exhibit low pressure because there is slightly less total mass in the column overhead (they are the result of net divergence). They tend to have convergence at lower levels, divergence at upper levels and net upward motion, hence unsettled and overall more cloudy conditions.


However upper lows have an additional large term. Cold air is denser than warm air and pressure is hydrostatic (to a very close approximation) so pressure decreases faster with height in a cold air mass. Therefore at a given significant height with the same total mass in the column, pressure will be lower in a cold air mass than in a warm air mass. Above about 15K feet the temperature term overwhelmingly dominates so low pressure that high up usually means a cold air mass underneath.


I get the pressure-altitude thing, but that's descriptive only. My question is where does the cold air come from? We see upper level lows without any particularly cold air mass at the surface at all, especially in summer, and at low latitudes. The only source of cooling I can think of is radiation to space.
Quoting 41. Xyrus2000:



That's 384 hours out. You might as well take random water colors and throw them at a paper map. :P


Probably not random. Stock up more on the reds and less on the blues for decades out Just sayin' :-)
Quoting 71. BayFog:


I get the pressure-altitude thing, but that's descriptive only. My question is where does the cold air come from? We see upper level lows without any particularly cold air mass at the surface at all, especially in summer, and at low latitudes. The only source of cooling I can think of is radiation to space.


Upper lows that are not cold always have a surface low accompanying them.. always in a hydrostatic atmosphere. Upper lows with no temperature gradient at the surface and no surface low OR that intensify with height are colder aloft hence there is more instability. This situation is common in the warm season and upward motion is itself destabilizing and cools the column aloft much more than at the surface.


The most common source of cooling for the ones that aren't simply cold air getting cut off in a jet stream loop, is upward motion which will cool the column if the air is statically stable (usual). There are many ways for the atmosphere to act as a refrigerator converting kinetic energy to potential energy by intensifying a cool area and intensifying the temperature gradients between it and the surrounding warmth (and model bugs produce even more, in particular erroneous polar winter stratosphere cooling beyond what is observed in nature )
76. bwi
Updated 3-day still the nasty for New Orleans
Quoting 52. washingtonian115:

I was about to make a comment on the tropical waves as well.If the tropical waves are anything like the ones last year then I don't see why we can't have at least a average hurricane season.The waves were very strong and resilient in 2015 which is probably why we saw a more active MDR than what many people were predicting.I saw some climate models predicting a wet Sahara so its something to look out for.
Quoting 74. georgevandenberghe:



Upper lows that are not cold always have a surface low accompanying them.. always in a hydrostatic atmosphere. Upper lows with no temperature gradient at the surface and no surface low OR that intensify with height are colder aloft hence there is more instability. This situation is common in the warm season and upward motion is itself destabilizing and cools the column aloft much more than at the surface.


The most common source of cooling for the ones that aren't simply cold air getting cut off in a jet stream loop, is upward motion which will cool the column if the air is statically stable (usual). There are many ways for the atmosphere to act as a refrigerator converting kinetic energy to potential energy by intensifying a cool area and intensifying the temperature gradients between it and the surrounding warmth (and model bugs produce even more, in particular erroneous polar winter stratosphere cooling beyond what is observed in nature )

But upward motion is usually a result, not a cause of cold air aloft. If it's dynamically forced upward motion without cold air aloft, that would carry and release heat, not cold, to the upper levels. It makes more sense to imagine that radiationally cooled air aloft is the primary source, which would tend to collect in cyclonic loops of the upper flow.
Another warm surge coming for next week, after the rain Sun-Tues.
7 Day Precipitation Estimates
Quoting 78. BayFog:


But upward motion is usually a result, not a cause of cold air aloft. If it's dynamically forced upward motion without cold air aloft, that would carry and release heat, not cold, to the upper levels. It makes more sense to imagine that radiationally cooled air aloft is the primary source, which would tend to collect in cyclonic loops of the upper flow.


Air that is lifted cools at the dry (or moist once saturated) adiabatic lapse rate which is larger than in the surrounding air in a statically stable air mass. So upward motion in stable air ALWAYS cools and downward motion ALWAYS warms. Temperature is not conserved.. potential temperature is. Potential temperatures almost
always increase with height so upward motion vertically advects lower potential temperatures up. Moisture (once saturated) greatly complicates this; saturated parcels when the lapse rate is higher than the moist adiabatic rate are unstable and will convect.

If the atmosphere is unstable, potential temperature decreases with height and upward motion warms and downward motion cools. However an unstable atmosphere overturns quickly and absolute instability is rare. When you look for instability you are always finding situations that will make a sounding unstable and it will then convect but soundings that ARE unstable and not convecting with convection that would wipe out the instability, are rare. I'll leave it to severe weather forecasters to describe situations where very large amounts of potential instability can develop, generally contained under some kind of cap and so not released immediately, which when released, converts to enormous amounts of vertical kinetic energy in convection (CAPE)

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
207 PM CST THU MAR 10 2016

.DISCUSSION...

FRONTAL BOUNDARY DRAPED FROM SOUTHWEST INDIANA DOWN ALONG THE
MISSISSIPPI RIVER INTO LOUISIANA. SIXTY KNOT LOW LEVEL JET UP
THROUGH MISSISSIPPI INTO WESTERN TENNESSEE CARRYING A STRONG PLUME
OF MOISTURE FROM TROPICS NORTHWARD BUTTING UP AGAINST BOUNDARY.
MOISTURE TRANSPORT BECOMES STRONGEST ACROSS MIDDLE TENNESSEE THIS
EVENING IN PHASE WITH STRONGEST VERTICAL VELOCITIES BEFORE
SHIFTING EASTWARD AFTER MIDNIGHT.
SO EXPECT TO SEE RAIN TRAVERSE
ALL OF MIDDLE TENNESSEE THIS EVENING WITH A FEW THUNDERSTORMS.
ACTIVITY COULD OCCASIONALLY FORM A LINE. MOISTURE STILL RATHER
DEEP ON FRIDAY BUT NOT MUCH IN THE WAY OF FORCING CAN BE FOUND
FRIDAY MORNING BUT BY AFTERNOON AND DURING FRIDAY EVENING VERTICAL
VELOCITIES QUICKLY CLIMB AS UPPER LOW BEGINS TO EJECT OUT OF SOUTH
TEXAS/OLD MEXICO WITH SHORTWAVE QUICKLY EJECTING THIS WAY. SO I`VE
GOT LOWER POPS DURING THE MORNING FRIDAY THEN INCREASE POPS FOR
FRIDAY AFTERNOON AND NIGHT. THIS IS ABOUT AS A PROGRESSIVE A
PATTERN FOR THE NEXT SEVERAL DAYS AS THIS FORECASTER HAS SEEN IN
A WHILE.
ENERGY HITTING THE WEST COAST SEEMS TO BE ENDLESS. THE
GOOD NEWS IS TEMPS WILL REMAIN WELL ABOVE CLIMATOLOGY.


Quoting 77. Climate175:




There is that area of below-normal precip below the above-normal area. However, nonetheless, we will likely get some early MDR storms this year, unlike recent years.
Quoting 79. Climate175:

Another warm surge coming for next week, after the rain Sun-Tues.


Looks we will be getting some 80's here soon ...annoyed by that.
Received a little over an inch of rain this morning ...most of it falling on my commute, was coming down furiously as roads were flooding. Stopped as I arrived at my destination. Sun came out after that and dried things up nicely
Quoting 79. Climate175:

Another warm surge coming for next week, after the rain Sun-Tues.


Never really gonna cool down to typical March rawness (40s and dripping) either. Every day till next Friday will break 60F.
Quoting 84. justmehouston:



Looks we will be getting some 80's here soon ...annoyed by that.
Received a little over an inch of rain this morning ...most of it falling on my commute, was coming down furiously as roads were flooding. Stopped as I arrived at my destination. Sun came out after that and dried things up nicely
We never really had much of a winter here in D.C so the fact that we're seeing 80 degree temperatures this early is of no surprise.I suspect most species of trees up here to be fully leafed by the end of this month.
The quasistationary frontal band has now shifted southward to include the central SF Bay Area. Rain pouring down in our locale. This also means it will be pouring down in the central Sierra. Snow levels are high given the subtropical origin of the moisture stream, but low enough for heavy wet snow in the High Sierra.

Quoting 83. HurricaneFan:



There is that area of below-normal precip below the above-normal area. However, nonetheless, we will likely get some early MDR storms this year, unlike recent years.

Assuming the SAL behaves accordingly.
Quoting 86. washingtonian115:

We never really had much of a winter here in D.C so the fact that we're seeing 80 degree temperatures this early is of no surprise.I suspect most species of trees up here to be fully leafed by the end of this month.


They weren't leafed out until mid April 2012 and I don't expect them to be earlier this year. Normal date for full leaf out here in DC 'burbs is about May 10 but it varies a lot from year to year.

Years ago, in 1990, I went with my singles (yeah things change) group for a memorial day getaway in Western MD near Deep Creek Lake. Trees there were just leafing out. Oaks were shedding pollen and leaves were tiny and that gold color Robert Frost wrote about in his poem about the transience of gold color in nature. They are normally in that stage here in mid to late April. In 1979 at PSU it happened mid May.
Quoting 81. georgevandenberghe:



Air that is lifted cools at the dry (or moist once saturated) adiabatic lapse rate which is larger than in the surrounding air in a statically stable air mass. So upward motion in stable air ALWAYS cools and downward motion ALWAYS warms. Temperature is not conserved.. potential temperature is. Potential temperatures almost
always increase with height so upward motion vertically advects lower potential temperatures up. Moisture (once saturated) greatly complicates this; saturated parcels when the lapse rate is higher than the moist adiabatic rate are unstable and will convect.

If the atmosphere is unstable, potential temperature decreases with height and upward motion warms and downward motion cools. However an unstable atmosphere overturns quickly and absolute instability is rare. When you look for instability you are always finding situations that will make a sounding unstable and it will then convect but soundings that ARE unstable and not convecting with convection that would wipe out the instability, are rare. I'll leave it to severe weather forecasters to describe situations where very large amounts of potential instability can develop, generally contained under some kind of cap and so not released immediately, which when released, converts to enormous amounts of vertical kinetic energy in convection (CAPE)



But given how unusual it is overall for air to be forced upward into stable air, and to stay there without immediately falling back to the surface ANTI-cyclonically rather than persist in cyclonic upper level devils, how can that account for the relative abundance of cold upper level lows?
PUBLIC RELEASE: 10-MAR-2016
European Centre for Medium-Range Weather Forecasts - Model upgraded to best ever
ECMWF

Link
Quoting 77. Climate175:




I don't want to give too much credence to the CFS, but that is a substantial departure from previous years and is very promising for an active Cape Verde season. Typical for La Nina years.
This year will be active and much more than last year I gotta gut feeling this may be the year we end this nine year Cat 5 drought
Quoting 94. wunderkidcayman:

This year will be active and much more than last year I gotta gut feeling this may be the year we end this nine year Cat 5 drought


Based on what information?
It almost appears as if the El Nino has split in two according to this SST anomaly map...wow...
Quoting 94. wunderkidcayman:

This year will be active and much more than last year I gotta gut feeling this may be the year we end this nine year Cat 5 drought
I think so too buddy.
Quoting 95. Bucsboltsfan:



Based on what information?


La Niña coming

Also current oceanic heat content in the Caribbean is quite high maybe the highest since 2010 and is similar to the active years between 2005-2010 even in this early time of year current SSTs are already higher than this time last year

I say stronger tropical waves due to a stronger and much further N monsoon trof/ITCZ

I say this year we will see lower shear higher SST/A/heat content lower trades lower pressures

Anyway the confidence in this will increase within the next month or two as other hurricane season forecast comes out
Quoting 90. BayFog:


But given how unusual it is overall for air to be forced upward into stable air, and to stay there without immediately falling back to the surface ANTI-cyclonically rather than persist in cyclonic upper level devils, how can that account for the relative abundance of cold upper level lows?


It's not very unusual. It does involve work being done on the atmosphere to increase the temperature gradients, the work then converts to potential energy. But in the midlatitudes most upper lows form from cold air that gets cut off from the westerlies and polar vortex, a common to general process. Cutoff formation is more likely when the polar vortex is warming in spring and the flow becomes unbalanced (excessively fast for coriolis force to be balanced by the weakening pressure gradient aloft caused by warming). Cutoffs are very common in the midlatitudes in mid to late spring for this reason. The spin up process in the fall seems to happen on larger time and space scales without so many cutoffs and it's is beyond my knowledge to explain exactly why.

BTW an example of a low that weakens with height is a tropical cyclone (hurricane). It is warm core, pressure difference decreases with height since the core is significantly warmer. THis warming comes from convection and latent heat release. Upward motion in a conditionally unstable atmosphere DOES heat the region once condensation occurs and (very simplisticly) the hurricane behaves as a heat pipe transporting heat aloft from the surface.
Quoting 97. Andrebrooks:

I think so too buddy.


It's definitely a possibility. We could get 15+ storms if the MDR is warm enough AND we have La Nina. The SAL is also another important factor, and La Nina may make it slightly more favorable for a weak SAL. Either way, the western Atlantic/GOM should be very active in 2016, regardless of how the AMO is, due to forecast above-normal precipitation, well above normal SSTs and below-normal shear -- watch out for a strong landfalling hurricane next year somewhere in Florida, Gulf Coast, or the Southeast.
Quoting 96. HurricaneFan:

It almost appears as if the El Nino has split in two according to this SST anomaly map...wow...


Soon it will be no El Niño at all

Hi folks, late good night hello from Europe. Hope everybody is well despite the severe weather in the US. High pressure with calm weather in Germany, currently, so nothing to report from my place.
Stumbled across those news below from our beloved "Euro" though. Hope it helps the forecasts :-)

New forecast model cycle brings highest-ever resolution
ECMWF, 10 March 2016
ECMWF has launched a new model cycle bringing improved global weather forecasts at record-breaking resolution.
The new grid on which the forecasts are run comprises up to 904 million prediction points, three times as many as before.
Together with other upgrades to ECMWF’s Integrated Forecasting System (IFS), the changes mean that Europe’s weather can now be predicted with more detail, with greater accuracy and, as a result, up to half a day further ahead.
The new cycle reduces the horizontal grid spacing for high-resolution forecasts from 16 km to just 9 km.
Ensemble forecasts, which describe the range of possible weather scenarios and the likelihood of their occurrence, usually use twice the grid spacing of high-resolution forecasts. They are now at 18 km up to forecast day 15 and 36 km thereafter.
The vertical grid spacing is unchanged.
The assimilation of weather observations into the forecasting system has also been improved. This enables a better assessment of the current state of the atmosphere used to initialise a forecast.
ECMWF’s Director-General, Florence Rabier, said the improvements in accuracy and range represented “a big step forward”.
“The impact of the weather and its potentially deadly extremes is one of the key challenges facing emergency response services, policymakers, and industry. This makes the role of the National Meteorological Services that we serve critical to society,” she observed. ...

Whole news release see link above.

Quoting 100. HurricaneFan:



It's definitely a possibility. We could get 15+ storms if the MDR is warm enough AND we have La Nina. The SAL is also another important factor, and La Nina may make it slightly more favorable for a weak SAL. Either way, the western Atlantic/GOM should be very active in 2016, regardless of how the AMO is, due to forecast above-normal precipitation, well above normal SSTs and below-normal shear -- watch out for a strong landfalling hurricane next year somewhere in Florida, Gulf Coast, or the Southeast.


I agree

I can also can see some strong landfall ing hurricanes in the Caribbean too

Rain coming again..... WU forecast .28"
Flash Flood Watch
FLOOD WATCH
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
401 PM PST THU MAR 10 2016

...PERIODS OF MODERATE TO HEAVY RAIN EXPECTED INTO SUNDAY THAT
COULD LEAD TO FLASH FLOODING...

CAZ006-505>509-111400-
/O.CON.KMTR.FF.A.0007.000000T0000Z-160314T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000 Z.OO/
SAN FRANCISCO-
COASTAL NORTH BAY...INCLUDING POINT REYES NATIONAL SEASHORE-
NORTH BAY INTERIOR VALLEYS-NORTH BAY MOUNTAINS-
SAN FRANCISCO BAY SHORELINE-SAN FRANCISCO PENINSULA COAST-
401 PM PST THU MAR 10 2016

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH SUNDAY AFTERNOON...

THE FLASH FLOOD WATCH CONTINUES FOR

* A PORTION OF CALIFORNIA...INCLUDING THE FOLLOWING AREAS...
COASTAL NORTH BAY...INCLUDING POINT REYES NATIONAL SEASHORE...
NORTH BAY INTERIOR VALLEYS...NORTH BAY MOUNTAINS...SAN
FRANCISCO...SAN FRANCISCO BAY SHORELINE AND SAN FRANCISCO
PENINSULA COAST.

* THROUGH SUNDAY AFTERNOON

* EXCESSIVE RAINFALL ON ALREADY SATURATED SOILS AND SWOLLEN SMALL
CREEKS AND STREAMS WILL LIKELY RESULT IN FLOODING THROUGH THE
WEEKEND.

That would be we-all.
Quoting 96. HurricaneFan:

It almost appears as if the El Nino has split in two according to this SST anomaly map...wow...

Lol on here too 😄.
A little to early to see this eh?
Quoting 107. washingtonian115:

A little to early to see this eh?

yep, here's my March numbers:
17 named storms
9 hurricanes
6 major hurricanes
Quoting 98. wunderkidcayman:



La Niña coming

Also current oceanic heat content in the Caribbean is quite high maybe the highest since 2010 and is similar to the active years between 2005-2010 even in this early time of year current SSTs are already higher than this time last year

I say stronger tropical waves due to a stronger and much further N monsoon trof/ITCZ

I say this year we will see lower shear higher SST/A/heat content lower trades lower pressures

Anyway the confidence in this will increase within the next month or two as other hurricane season forecast comes out


What about the dry sinking/stable air that has dominated the past couple of years. That has been the main issue and you didn't address it?
Quoting 109. Bucsboltsfan:



What about the dry sinking/stable air that has dominated the past couple of years. That has been the main issue and you didn't address it?
I guess that is yet to be seen.If the model that was posted on here about the Sahara desert being wet is anywhere near correct then we probably won't have any problems with dry air in the MDR.
Seen 3 inches of rain today!!!!
Link
If you have a facebook, please like my weather page please, thanks.
Quoting 106. tiggerhurricanes2001:


Lol on here too 😄.
Hey there Malik.
Quoting 108. Andrebrooks:

yep, here's my March numbers:
17 named storms
9 hurricanes
6 major hurricanes

There is having confidence in La Nina forming, and then there is doubling down on La Nina forming with an active hurricane season in a AMO- year.
Any idea on how this low over Mexico is affecting spring bird and monarch migrations? I've seen Turkey vultures overhead in north-central Oklahoma, so some birds are already on the move. TVs usually precede Scissor-Tailed Flycatchers only by a short margin. I wonder, too, about all the birds that might be trying to make their annual trek across the GoM. Spring has arrived early up north, but perhaps that has caused many species to get caught in terrible weather. I hope that is not the case.
Quoting 107. washingtonian115:

A little to early to see this eh?

omg put that away please!!!
Quoting 103. wunderkidcayman:



I agree

I can also can see some strong landfall ing hurricanes in the Caribbean too
I didn't expect you to say that.
Heat content gone.
What's your mother tongue Gearsts?
Quoting 120. BaltimoreBrian:

What's your mother tongue Gearsts?
Love this picture.
On the beach, with sunblock, at Tenate Island, Indonesia. Click photograph to expand.



Somewhere in Louisiana there is a guy, up to his neck in water watching his mobile home and all his meager possessions floating away and going "That Global Warming is nothing but a hoax by Democrats"

Cripes probably several hundred .....
Quoting 103. wunderkidcayman:



I agree

I can also can see some strong landfall ing hurricanes in the Caribbean too


You mean in the NW Caribbean south of Cuba ?
Quoting 118. Gearsts:

Heat content gone.

Impossible .... It's not gone, it's just moved elsewhere ..... like into the atmosphere

126. JRRP7
Quoting 121. Gearsts:

Love this picture.


recuerdo exactamente ese minuto... temprano en la mañana soplaba bastante fuerte la brisa
fue mi primera experiencia en un ciclon
Quoting 122. BaltimoreBrian:

On the beach, with sunblock, at Tenate Island, Indonesia. Click photograph to expand.






Cool shot. Looking forward to the August 21st, 2017 eclipse. Flying out to Charleston, SC for it.
Quoting 116. Gearsts:

omg put that away please!!!
lol.why?
129. JRRP7
well see you tomorrow
That last link is some scary stuff BB...

BTW, I just released some methane and it wasn't all that pretty. In fact, the cat ran out of the room.
Although the current synoptic chart is showing the front already south of us, the satellite and ground truth says otherwise. Local wind and wavering pressure patterns, plus the radar point to the front having become stationary with waves along it right thru the heart of the Bay Area, at least over the last several hours.
Record breaking wind storm here in Wa, 109mph at Mt Baker ski area @ 5000'. 80mph yet to be confirmed would be a record for Bellingham. Oddly not a drop of rain all day. Power was out for pretty much the whole 14hrs the storm raged, most intense storm I've ever experienced.



I dont have a picture of a hydra but I spotted this western skink today and thought a pic would be appropiate.

Check out the nwsseattle twitter site for pics of the storm destruction.
Almost 6 inches of rain here. More to come. Patrap, how's everything over there.
Talk about a warm February in Anchorage (and Alaska in general):

This February was particularly warm statewide, with an average temperature of 17.2 degrees, compared to the 20th-century average of 4.8 degrees, according to the centers’ database.

Full Article: alaska-just-had-its-warmest-february
Sup Dakster,
Quoting 136. PedleyCA:

Sup Dakster,


Flooding issues in SoCal for you Ped?
Quoting 137. Dakster:



Flooding issues in SoCal for you Ped?

Not likely, The forecast is for .31" of rain. Doubt we will need an ARK for that.
Maybe get a sandbag ready -- just in case you need to sprinkle some on top of the puddle that could form.
Was a epic trip up to Baton Rouge for the show there, then came home by Midnight....thru some crazy rain rates near Gramercy on I-10 eastbound.

Glad to back in Nola safe and sound.







Flash flood emergency is in effect for my parish you guys. Please pray for my area and home. We've seen close to 8 inches now. We could see over 13 inches of rain.
Quoting 142. Andrebrooks:

Flash flood emergency is in effect for my parish you guys. Please pray for my area and home. We've seen close to 8 inches now. We could see over 13 inches of rain.


Be SAFE and good luck Andre!
Quoting 138. PedleyCA:


Not likely, The forecast is for .31" of rain. Doubt we will need an ARK for that.


Maybe a rubber dinghy!
Quoting 132. BayFog:

Although the current synoptic chart is showing the front already south of us, the satellite and ground truth says otherwise. Local wind and wavering pressure patterns, plus the radar point to the front having become stationary with waves along it right thru the heart of the Bay Area, at least over the last several hours.



All is good........keep it coming til that hose busts!
Quoting 143. HurricaneHunterJoe:



Be SAFE and good luck Andre!
Thanks Joe. We are over 8 inches of rain now. Rescues are being conducted in my city.
Quoting 138. PedleyCA:


Not likely, The forecast is for .31" of rain. Doubt we will need an ARK for that.


Let's hope the models are wrong and we get more than forecast! When the models are wrong, we usually get shortchanged...........I think it's about time to go the other way....let's hope the front/trof slows or stalls over us and we get 1.31"!

Jan 2016-7.10"
Feb 2016-0.04
Mar 2016-0.86 so far
Quoting 146. Andrebrooks:

Thanks Joe. We are over 8 inches of rain now. Rescues are being conducted in my city.

Well, you wanted some El Nino weather! I just hope everyone heeds the warnings and get out or do as requested by local emergency organizations and keep loss of life as low as possible! Again, be safe Andre!
True. Lol. But I do hope everyone be safe from this weather.
Quoting 148. HurricaneHunterJoe:


Well, you wanted some El Nino weather! I just hope everyone heeds the warnings and get out or do as requested by local emergency organizations and keep loss of life as low as possible! Again, be safe Andre!
Quoting 149. Andrebrooks:

True. Lol. But I do hope everyone be safe from this weather.


Im with you on that........hope ALL stay safe! Boy, that's a whole lotta rain! Also hope the tornados are kept to a minimum!


A winter weather system will race over Southern California Friday night bringing rain, mountain snow and gusty winds. The precipitation will begin late Friday afternoon in western San Bernardino and Orange Counties, then spread southeast Friday evening. The storm will exit the region early Saturday morning.
Quoting 151. HurricaneHunterJoe:



Im with you on that........hope ALL stay safe! Boy, that's a whole lotta rain! Also hope the tornados are kept to a minimum!
Right.


Looks like it will be coming down for a while yet!
Quoting 154. HurricaneHunterJoe:



Looks like it will be coming down for a while yet!
It's been coming down since 1:30pm yesterday.
9 inches of rain has fallen now. Expect some wicked winds from that line southwest of me.
Quoting 107. washingtonian115:

A little to early to see this eh?


Link please?
long summer ahead. not only are we a little worried about an uptick in hurricane activity but also the spread of zika. it seems as if there is no stopping it.
stay alert and safe folks over there............................................. ........
161. beell
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
459 AM CST FRI MAR 11 2016

...THE UPPER FLOW WILL BECOME MORE WEST-SOUTHWESTERLY DURING THE FIRST OF THE UPCOMING WEEK. THIS WILL HELP PROMOTE A WARMING TREND WITH LITTLE CLOUDS BEING COUPLED WITH A SOUTHWESTERLY LOW-LEVEL FLOW AS SEEN BY THE ECWMF 850 MB FORECASTS ON MONDAY AND TUESDAY...

Some sunshine in the forecast for SE TX next week under a canopy of cumulus minusculus. We have had some large ones overhead this week.
162. MahFL
Lake Shasta continues to fill :

69% of Total Capacity
91% of Historical Avg. For This Date.
Near a foot has fallen here in Hammond, Louisiana. Schools, businesses, government, and the city of Hammond are closed. People are getting rescued, power is out in places. Please pray for us.
Gee I sure hope this doesn't verify..way out in time but, those poor flooded out folks there..
2 more days......................NWS New Orleans..................
Detailed Forecast



Today

Showers and thunderstorms. Some of the storms could produce heavy rain. High near 72. Southeast wind around 15 mph. Chance of precipitation is 100%. New rainfall amounts between 3 and 4 inches possible.


Tonight

Showers and thunderstorms. Some of the storms could produce heavy rain. Low around 67. Southeast wind around 15 mph. Chance of precipitation is 90%. New rainfall amounts between 1 and 2 inches possible.


Saturday

Showers and thunderstorms. Some of the storms could produce heavy rain. High near 73. Southeast wind around 15 mph. Chance of precipitation is 90%. New rainfall amounts between 1 and 2 inches possible.


Saturday Night

A 30 percent chance of showers before midnight. Mostly cloudy, with a low around 63. Southwest wind around 10 mph.
157

Link please?


Link
Quoting 109. Bucsboltsfan:



What about the dry sinking/stable air that has dominated the past couple of years. That has been the main issue and you didn't address it?


I agree, the cold pool across the far North Atlantic could cause problems as warm anomalies set up from the 20N up to 50N while the Caribbean cools compared to further north and this is showing up on models that are showing La-Nina. This is a difficult forecast for this Hurricane Season.
Quoting 160. BaltimoreBrian:

Astronomers say they've found the biggest structure in the universe and they named it the BOSS


Bruce Springsteen may be a big star, but he's not that big.
Good Morning. The Mexican low is finally on the move but slowly rotating to the N-NE at a snails pace. Not only does Louisiana continue to be pummeled, but the moisture trail now has expanded into large bands flowing North from the Yucatan with some convective activity in the Gulf as they move on-shore due to the warmer sst's in the Eastern Half of the Gulf of Mexico.

Note that the ULL plume in the middle of the Gulf coincides (right next to) with the large warm Gulf eddy; that baroclinic interaction between the two is fueling the off-shore t-storms this morning.

Also note that the current trajectory is right up the spine of the Mississippi River; this is going to cause massive flooding downstream well into next week; no real relief in sight for several days when all is said and done.

We are all praying for you folks in Louisiana and Mississippi this morning :



Southern Mississippi Valley sector loop

Starting to get some slack in the rain. Last night saw a couple of heavy downpours. Rivers/creeks are way up in my area but most roads are still passable in the Baton Rouge area. Had to cross one section of road that had about 6-8" of standing water this morning. Not sure when we're due to crest here but getting home may prove to be difficult this afternoon if I had to guess.
Quoting 161. beell:

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
459 AM CST FRI MAR 11 2016

...THE UPPER FLOW WILL BECOME MORE WEST-SOUTHWESTERLY DURING THE FIRST OF THE UPCOMING WEEK. THIS WILL HELP PROMOTE A WARMING TREND WITH LITTLE CLOUDS BEING COUPLED WITH A SOUTHWESTERLY LOW-LEVEL FLOW AS SEEN BY THE ECWMF 850 MB FORECASTS ON MONDAY AND TUESDAY...

Some sunshine in the forecast for SE TX next week under a canopy of cumulus minusculus. We have had some large ones overhead this week.

It's about time for a BEELL sighting. It appears the rumors of your demise were greatly exaggerated...
174. weathermanwannabe
1:46 PM GMT on March 11, 2016

We are all praying for you folks in Louisiana and Mississippi this morning :



Absolutely.


A little early to see this too :)
What a historic rain event with Sunday putting the same area under a threat for severe weather and more heavy rains. For those affected, they painfully know just how historically out of the normal this is. I know there's an election going on, but have we become so accustomed to this new normal that an epic event like this doesn't even register with most Americans anymore? Crazy, we've never seen a set up this extreme ever before. Strongest upper level low ever producing a one in a thousand year likely rain event. Wow!

This is from the abandoned six flags in New Orleans.It has been abandoned now for 10 going on to 11 years.It was submerged under 8 feet of water for a month and stands as a painful reminder of what happened on the east side of the city which was especially hit hard during Katrina.The swamp is now reclaiming it with some parts of the park underwater and overgrown with vegetation.Wild boars along with snakes and alligators call the place home now.
Quoting 178. CaribBoy:



A little early to see this too :)


Indeed. Last decade, worldwide we've seen record tornado seasons and record low tornado seasons. We've seen record snows and cold many places only to be followed by record warm winters. We've seen historic hurricane seasons and well below average seasons. We've seen record drought places only to be followed by record rains. It's worldwide. Don't be surprised at all, count on it, another record hurricane season is coming to the Atlantic basin and I think it could be this year. If not, then soon. Just my personal read on the new climate reality we find ourselves in. It's one of extremes and getting more so. And it's faster and faster now.
184. MahFL
Quoting 180. DeepSeaRising:

... I know there's an election going on, but have we become so accustomed to this new normal that an epic event like this doesn't even register with most Americans anymore? ...


How do you know this is not registering with most Americans ?
Also remember this is a couple of States out of 50. Flooding regularly occurs in this part of the USA, one resident was on tv yesterday and said he'd been flooded 4 times in the 1990's.
Quoting 180. DeepSeaRising:

What a historic rain event with Sunday putting the same area under a threat for severe weather and more heavy rains. For those affected, they painfully know just how historically out of the normal this is. I know there's an election going on, but have we become so accustomed to this new normal that an epic event like this doesn't even register with most Americans anymore? Crazy, we've never seen a set up this extreme ever before. Strongest upper level low ever producing a one in a thousand year likely rain event. Wow!


If most Americans began to pay attention to the onslaught of "epic" weather events they *might* be forced to conclude that AGW is real and is likely contributing to the epic weather. Cognitive dissonance is difficult to endure. Better to ignore it and hope it goes away...

On a weather note, it's going to rain today. Again. Also, I'm glad to hear plantmoretrees fared OK through the storm yesterday. Other than a free car wash on the 520 floating bridge, it was largely a non event in Seattle. Although I did have friends lose power in North Seattle.
Quoting 184. MahFL:



How do you know this is not registering with most Americans ?
Also remember this is one State out of 50, in which flooding regularly occurs, one resident was on tv yesterday and said he'd been flooded 4 times in the 1990's.


I appreciate a fine question and a good point. When we see real movement in legislation to pass binding laws that really address AGW then I will believe it's really registering. I do not believe it is with the West masses. We say pretty words but don't take the hard choice options that will change the curve we're on. We're on a runaway train and we're just barely tapped the breaks. Real binding legislation is moving at a glacial pace and they're going to be gone soon. And so will our chance to blunt AGW if we don't get real fast.
JeffMasters has created a new entry.
188. MahFL
Quoting 185. Seattleite:



If most Americans began to pay attention to the onslaught of "epic" weather events they *might* be forced to conclude that AGW is real ...


Most Americans do believe in Global Warming:

"Polls show most Americans believe in climate change, but give it low priority"

http://www.pewresearch.org/fact-tank/2014/09/23/m ost-americans-believe-in-climate-change-but-give-i t-low-priority/

I get the sense YOU think most of the American public don't care, but in fact most do.