March 2010- In Like A Lamb, Out Like A Lion?

[wxdata]

ECMWF still forecast a rather potent upper system crossing Texas around March 1

[ticka1]

Severe weather this time? Sorry still can't read the maps as you posted above Dan....

[wxdata]

Severe weather this time? Sorry still can't read the maps as you posted above Dan....

Perhaps for someone in Texas. Since it looks like the air aloft will be cold enough, the system may bring Texas another snow threat. GFS is similar until Tuesday March 2 when it opens up the system as it moves eastward.

[don]

Yeah it does seem like it shows maybe some wintry precip around here on the backside of the low?

http://www.meteo.psu.edu/ewall/ECMWF_12z/f168.gif

[txsnowmaker]

Are the models depicting freezing or below freezing surface temperatures for the area during that time?

[srainhoutx]

All the same players are basiclly still 'on the table' for this storm. AO, NAO are still negative (although not as much) and a strong blocking regime is in place. There is a surge of moisture from the dateline as El Nino relaxes that would suggest the STJ will be involved. As always the eventual track remains uncertain at this range, but 1 more snow event (for Houston) would equal the 1973 analog that has been showing up via the ensembles. We shall see. I do think that there may be a severe side as well as a major winter storm for some folks.

[wxman57]

Are the models depicting freezing or below freezing surface temperatures for the area during that time?

Glad you asked! Not the GFS, that's for sure. I've been following the GFS forecasts for next Monday and they're nowhere near freezing. Temps in the mid 50s when the precip starts and dropping into the low 50s when it ends. Euro phases the system a little more but careful using those charts to predict when precip might be falling. Looks like a cold rain event for us at this point. We'll have to see what air might be coming down from the north as the upper low moves across. I think it could very easily be colder than the GFS is forecasting, but it doesn't have the look of a SE TX snow event yet.

18Z GFS Meteogram:

[txsnowmaker]

Are the models depicting freezing or below freezing surface temperatures for the area during that time?

Glad you asked! Not the GFS, that's for sure. I've been following the GFS forecasts for next Monday and they're nowhere near freezing. Temps in the mid 50s when the precip starts and dropping into the low 50s when it ends. Euro phases the system a little more but careful using those charts to predict when precip might be falling. Looks like a cold rain event for us at this point. We'll have to see what air might be coming down from the north as the upper low moves across. I think it could very easily be colder than the GFS is forecasting, but it doesn't have the look of a SE TX snow event yet.

18Z GFS Meteogram:

Got it. Thanks for the answer and the outlook at this point.

[sleetstorm]

What are the dew points currently predicted to be for March 1st?

[wxman57]

What are the dew points currently predicted to be for March 1st?

See the meteogram I posted on page 1 of this thread. The green line is dew points. GFS is currently predicting dew points around 54F.

[Ptarmigan]

This model is not predicting any freezing temperatures for next week. Still bears watching.

http://wxweb.meteostar.com/sample/sampl ... ?text=kiah

[wxman57]

06Z GFS is a tad colder for next Monday but still just cold rain with temps in the upper 40s to low 50s:

[srainhoutx]

Well the 12Z ECMWF paints an interesting picture for parts of TX. Impressive low near Galveston and on to New Orleans and yet another dump of cold air.

[wxman57]

Looks like strong warm air advection ahead of that ECMWF low on Monday. So more cold rain. The airmass over Texas looks significantly warmer than with the last event. GFS doesn't even indicate any snow south of the Red River with it. May be more interesting east of Texas (as a storm). Mostly rain/thunderstorms, though. The way the 168hr Euro looks, there may be several systems phasing along the East Coast.

Here's a 12Z GFS meteogram. Mid to upper 40s and rain. Temps look reasonable. Not too exciting.

[wxman57]

And a 12z GFS extended outlook meteogram. More miserable cold for the 2nd week of March. No temperature above 65F for the next 2 weeks.

[srainhoutx]

The HPC Final Extended will raise an eyebrow...

EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
152 PM EST WED FEB 24 2010

VALID 12Z SAT FEB 27 2010 - 12Z WED MAR 03 2010

...SIGNIFICANT WINTER WEATHER THREAT FOR THE SW/SRN/SE US AND
POSSIBLY MID-ATLC NEXT WEEK...

THE MODELS CONTINUE TO ADVERTISE A RETROGRADING POSITIVE MID-UPPER
LEVEL HEIGHT ANOMALY FROM EASTERN INTO W-CENTRAL CANADA. THIS
SHOULD ALLOW AN AMBIENT CLOSED NORTHEAST VORTEX TO EXIT STAGE
RIGHT OVER THE WEEKEND...YET TRAP SOME MID-LEVEL ENERGY BACK
ACROSS THE MIDWEST NEXT WEEK. REPERCUSSIONS ARE MANY FOR ITS
INTERACTION WITH A NEARLY CLOSED CYCLONE ALOFT/STRONG SHORTWAVE
WHICH SPLITS OUT OF THE EASTERN PACIFIC TROUGH IN A POTENT SRN
STREAM TO NEAR 4 CORNERS BY SUN. THIS ENERGETIC FLOW/SYSTEM THEN
PROGRESSES BODILY/STEADILY EASTWARD OVER THE SOUTHERN TIER OF THE
COUNTRY...WITH QUESTION MARKS WITH RESPECT TO WHETHER OR NOT
DIGGING MIDWEST NRN STREAM ENERGY IS STRONG ENOUGH TO LURE THE
SOUTHERN SYSTEM NORTHWARD OR MERGE WITH IT...AND IF SO HOW FAR
NORTH THE COMBINED SYSTEM COULD MOVE. WITH A TWO DAY TREND
SOMEWHAT TO THE SOUTH NOTED AMONGST THE MULTI-MODEL ENSEMBLE
MEMBERS...FELT THE BEST COURSE OF ACTION WAS TO GO IN THE MIDDLE
OF THE ENSEMBLE CLUSTERING RATHER THAN THE NORTHERN SIDE
CONSIDERING CONTINUITY. THIS SOLUTION ADVERTISES A SNOWSTORM
THREAT ACROSS THE SRN ROCKY STATES SUN OUT ACROSS THE SRN THEN
SERN US/LOWER MID-ATLANTIC MONDAY INTO WEDNESDAY NEXT WEEK AS A
DECENT CLUSTER OF ECMWF ENSEMBLE MEMBERS CLOSE OFF A VORTEX AT 500
HPA WITH HEIGHTS BELOW 5400 METERS INTO THE SOUTH. HOWEVER...A
CLUSTER OF GEFS/CANADIAN MEMBERS ARE LOCATED MORE NORTHWARD OVER
THE MID-ATLANTIC STATES. NEEDLESS TO SAY...SOME UNCERTAINTY
REMAINS CONCERNING THESE IMPORTANT SMALLER SCALE DETAILS AND
INTERACTIONS OF THIS FORECAST. THE FINAL HPC SURFACE
FRONTS/PRESSURE AND 500 MB PROGS MAINTAIN CLOSE HPC CONTINUITY AS
PRIMARILY DERIVED FROM 50-50 BLEND OF SIMILAR 00 UTC
GFS/ECMWF...ALBEIT ADJUSTED SLIGHTLY CLOSER TO THE SE US COAST
INTO NEXT MIDWEEK BASED ON POTENTIAL BEST SHOWN BY ECMWF ENSEMBLE
CLUSTERING. DESPITE UNCERTAINTIES WITH EMBEDDED SYSTEM
DETAILS...LARGER SCALE FLOW DEPICTION FROM THE MODELS AND
ENSEMBLES ARE ACTUALLY QUITE SIMILAR...WITH BELOW NORMAL FORECAST
SPREAD LEADING TO ABOVE AVERAGE FORECASTER CONFIDENCE. THIS
INCLUDES AMPLIFIED NRN STREAM FLOW POTENTIAL...LEAD SRN STREAM
ENERGY OUT FROM SW US THROUGH THE US SRN TIER/GULF OF MEX...AND
SUBSEQUENT RELOADING OF AMPLIFIED ERN PACIFIC TROUGH ENERGY AND
ASSOCIATED RENEWED US W COAST ORGANIZED PCPN POTENTIAL AGAIN BY
DAYS 6/7. ACCORDINGLY...THE MAIN WEATHER SYSTEMS HAVE A HIGHER
THAN NORMAL CHANCE OF DEVELOPING IN A VEIN SIMILAR TO
GUIDANCE...EVEN THOUGH THE FOCUS FOR SIGNIFICANT SENSIBLE WEATHER
IS MORE UNCERTAIN.

WE SEE MINIMAL COMPELLING REASON TO ALTER HPC CONTINUITY
SIGNIFICANTLY AFTER CONSIDERATION OF 12 UTC MODEL AND ENSEMBLE
GUIDANCE. OVERALL...12 UTC GUIDANCE CONTINUED TO SUPPORT A
SIMILAR LARGER SCALE PATTERN DEVELOPMENT FOR MUCH OF THE
PERIOD...BUT FORECAST SPREAD DID INCREASE SUBSTANTIALLY BY DAYS
6/7 WITH SYSTEM DEEPENING/TRACK OUT FROM THE SRN/SERN US/GULF OF
MEX TO THE WRN ATLANTIC. THE 12 UTC GFS/UKMET SEEM OUTLIERS WITH A
FAR SOUTHWARD SUPPRESSED OFFSHORE TRACK NOT SUPPORTED BY
CONTINUITY...12 UTC GFS ENSEMBLES...12 UTC CANADIAN...OR
ESPECIALLY THE 12 UTC ECMWF THAT STILL SUPPORTS DEEP COASTAL STORM
POTENTIAL.

ROTH/SCHICHTEL/RUBIN-OSTER

[wxman57]

I think that last underlined part about the GFS/UKMET being outliers refers to the projected path off the East U.S. Coast. Maybe another East Coast snow storm? The GFS does tend to take such systems out to sea too much.

[srainhoutx]

I think that last underlined part about the GFS/UKMET being outliers refers to the projected path off the East U.S. Coast. Maybe another East Coast snow storm? The GFS does tend to take such systems out to sea too much.

I agree. The first part of the text was from this morning. One thing we will have in our favor is more Pacific RECON. The GFS will start to lock in on a sensible solution. The G-IV has been getting a work out this winter season...

000
NOUS42 KNHC 241745
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1245 PM EST WED 24 FEBRUARY 2010
SUBJECT: WINTER STORM PLAN OF THE DAY (WSPOD)
VALID 25/1100Z TO 26/1100Z FEBRUARY 2010
WSPOD NUMBER.....09-086

I. ATLANTIC REQUIREMENTS
1. FLIGHT ONE -- TEAL 70
A. A61/ ACK/ 25/1300Z
B. AFXXX 09WSA TRACK61
C. 25/0900Z
D. DROPS EVERY 20 MINUTES OVER WATER
E. AS HIGH AS POSSIBLE/ 25/1500Z
F. COUNTERCLOCKWISE

2. SUCCEEDING DAY OUTLOOK.....NEGATIVE

II. PACIFIC REQUIREMENTS
1. FLIGHT ONE -- NOAA 49
A. P54/ 45.40N 166.0W/ 26/1200Z
B. NOAA9 38WSC TRACK54
C. 26/0800Z
D. 17 DROPS ON TRACK
E. 39,000 TO 45,000 FT/ 26/1800Z

2. OUTLOOK FOR SUCCEEDING DAY:
FLIGHT ONE -- NOAA 49
A. P56/ 44.9N 150.9W/ 27/1200Z
JWP

[wxdata]

SPC take on the storm:

" SUN FEB 28/...THE SRN EXTENT OF A DEEP UPPER TROUGH MOVING
INTO THE WRN STATES ON DAY 3 IS EXPECTED TO MOVE INTO THE SRN
PLAINS. MARGINAL INSTABILITY LATE SUNDAY NIGHT WILL SUPPORT TSTMS
WITH SOME ISOLATED SEVERE THREAT ACROSS PARTS OF CENTRAL/SRN TX."

[wxman57]

By the way, you might change the title of this thread to "March First Storm - In Like a Cold, Wet Lamb". (I think I'm sounding like Ed now)

Definitely nothing but cold rain here for Monday. Even the Dallas area is questionable for snow. They're sort of where we were with the event here earlier this week - just borderline.

Here's a meteogram off the latest GFS. Temps in the mid 40s and light rain Monday. It's interesting that in February of 2009 we had 21 days with highs over 70 degrees and 3 days over 80 degrees. In 2010, we've had only a single day with a high over 70 degrees (last Sunday) and only 9 days with highs over 60 degrees! Mean temperature is 6.8F below normal for this month, compared to 5.8F above normal last February. I'll take last February's temps!