Texas Winter 2010-2011

[Mr. Weather]

according to accuweather its suppose to rain/snow here in Houston on the night of the 3rd and morning of the 4th but im not putting that much confidence in it still to far out most likely it will change and just be rain if that

[srainhoutx]

Perhaps it's just me, but when guidance has been suggesting and now the HPC mentioning a phasing of the Polar Jet (northern stream) and the Southern Stream, an eyebrow is raised. The Euro looks down right cold. I'd be cautious regarding the short wave (500mb) pattern at this range. What I do see is the ensembles suggesting an interesting situation with lots of potential, but many finer details are yet to be determined. All in all at this range, we still have at lot to work out...


PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
352 AM EST TUE JAN 25 2011

VALID 12Z SAT JAN 29 2011 - 12Z TUE FEB 01 2011


THE LONGWAVE PATTERN IS EXPECTED TO UNDERGO A TRANSITION AS
FOLLOWING THE PROGRESSION OF A WEAK WAVE FROM THE GREAT LAKES
ACROSS THE NORTHEAST DAYS 3-4...THE ECMWF/ECMWF ENSEMBLE
MEAN/GFS/GEFS MEAN 500 MB HEIGHTS SHOW A LOWER AMPLITUDE/LONGER
WAVELENGTH TROUGH ACROSS THE CENTRAL TO EASTERN US. A CLOSED LOW
IN THE SOUTHERN STREAM EMERGES OUT OF BAJA CA AND GRADUALLY
WEAKENS/SHEARS EAST ACROSS THE SOUTHERN PLAINS SUN 30 JAN TO MON
31 JAN.

THE AMPLIFICATION OF THE 500 MB RIDGE ALONG THE WEST
COAST/NORTHEAST PACIFIC FAVORS AMPLIFICATION OF A WAVE TRAVELING
NORTH-SOUTH ACROSS THE SOUTHWEST US MON AND POSSIBLY INTO THE
SOUTHERN PLAINS TUE 01 FEB. THE PHASING OF THE NORTHERN AND
SOUTHERN STREAM WAVES LEAD TO SIGNIFICANT DIFFERENCES IN THE SFC
PRESSURE PATTERN. A BLEND OF THE 12Z-00Z ECMWF AND 12Z ECMWF
ENSEMBLE MEANS WAS USED TO MITIGATE DIFFERENCES IN THE SURFACE
FRONTAL POSITION.

THE CONFLUENT FLOW ALOFT MAY LEAD TO AN INCREASING UPPER LEVEL JET
AND PRECIP BREAKING OUT ALONG THE FRONTAL BOUNDARY. THE 00Z GFS
WAS ALONE IN AMPLIFYING PRIMARILY THE NORTHERN STREAM...PRODUCING
AN AREA OF LOW PRESSURE MOVING FROM MN TO THE UPPER LAKES ON TUE
01 FEB. THE GEFS MEAN SHOWED A MUCH LOWER AMPLITUDE 500 MB WAVE
AND CONSEQUENTLY MUCH HIGHER SFC PRESSURES.

THE 00Z GFS/00Z AGREE THE NEXT PACIFIC SHORTWV WEAKENS AS IT COMES
ASHORE IN VANCOUVER ISLAND FRI EVENING 29 JAN. THE 00Z GFS IS ON
THE SOUTHERN EDGE OF THE CLUSTER OF LOW SOLUTIONS OVER THE
NORTHEAST PACIFIC 00Z SAT-00Z SUN...WHERE THE WEAKER/FURTHER NORTH
GEFS MEAN MATCHES BETTER WITH THE ECMWF/12Z ECMWF ENSEMBLE MEAN.
THE MAJORITY MODELS/ENSEMBLE MEANS TAKE THIS WAVE AND PROPAGATE
DOWNSTREAM AND HELP TO FROM THE SOUTHWEST US TROUGH ON MON
NIGHT-TUE. THE DEEP LAYER RIDGE BECOMES REINFORCED OVER THE
NORTHEAST PACIFIC/ADJACENT PACIFIC NORTHWEST THEREAFTER THROUGH AT
LEAST TUE 01 FEB.

PETERSEN

[txagwxman]

Hmmm...less likely ice next week for DFW if this ECMWF close. GFS out to lunch again.

Remember all those cold GFS runs that got everyone giddy...remember these for the future next time---ok?

[orangeblood]

6z is mighty close to a big event for the Red River valley. Couple more days and we'll be in the excitement zone!

Yep, agreed Ntxw. I saw nothing in the overnight guidance that would diminish my enthusiasm for next week. The likelihood of something big (and wintry) happening in the Southern Plains appears to be growing.

One trend I've noticed in the models this winter, especially the European, is the correction towards troughs becoming more progressive than first depicted. Because of this progressive nature of these troughs this winter, energy has never really been allowed to dig far enough south to give Texas many chances for winter weather. Sure enough the European is trending towards this scenario once again. Hopefully this time around, the trend is broken.

Not trying to play devils advocate, just pointing out something I've noticed this winter with the models.

[srainhoutx]

Hmmm...less likely ice next week for DFW if this ECMWF close. GFS out to lunch again.

Remember all those cold GFS runs that got everyone giddy...remember these for the future next time---ok?

Oh really?

[Portastorm]

One trend I've noticed in the models this winter, especially the European, is the correction towards troughs becoming more progressive than first depicted. Because of this progressive nature of these troughs this winter, energy has never really been allowed to dig far enough south to give Texas many chances for winter weather. Sure enough the European is trending towards this scenario once again. Hopefully this time around, the trend is broken.

Not trying to play devils advocate, just pointing out something I've noticed this winter with the models.

Orangeblood, I think you raise an excellent point and something we do need to be mindful of going into next week. The well-known bias of the Euro has been to develop southwest cut-off lows and to be too slow in moving them out. While I personally have not noticed what you reference, I don't doubt you at all and your discovery would coincide with the well-known bias.

As srainhoutx just said so well ... we're getting more clarity on the general pattern but there are myriad number of finer details which have to be worked out.

[utweather]

6z is mighty close to a big event for the Red River valley. Couple more days and we'll be in the excitement zone!

Yep, agreed Ntxw. I saw nothing in the overnight guidance that would diminish my enthusiasm for next week. The likelihood of something big (and wintry) happening in the Southern Plains appears to be growing.

One trend I've noticed in the models this winter, especially the European, is the correction towards troughs becoming more progressive than first depicted. Because of this progressive nature of these troughs this winter, energy has never really been allowed to dig far enough south to give Texas many chances for winter weather. Sure enough the European is trending towards this scenario once again. Hopefully this time around, the trend is broken.

Not trying to play devils advocate, just pointing out something I've noticed this winter with the models.

Yep, and without the pineapple express connection, cloudy and cold has been the rule.

[srainhoutx]

Morning Update from the HPC:

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
903 AM EST TUE JAN 25 2011

VALID 12Z SAT JAN 29 2011 - 12Z TUE FEB 01 2011

THE LONGWAVE PATTERN IS EXPECTED TO GRADUALLY TRANSITION FROM A
MEAN RIDGE OVER THE WEST/TROUGH OVER THE EAST ON DAY 3 TOWARD A
MEAN TROUGH OVER THE ROCKIES/RIDGE OVER THE SOUTHEAST BY DAY 7.
THE MANNER IN WHICH INDIVIDUAL MODELS ACTUALLY ARRIVE AT THEIR
PREDICTIONS VARIES CONSIDERABLY HOWEVER...WHICH IS CONFIRMED BY
THE UNUSUALLY LARGE DETERMINISTIC SOLUTION SPREAD ENTERING DAY
3...LAGGED-AVERAGE FORECASTS FROM THE GFS/ECMWF...AND THE TOTAL
ENSEMBLE SPREAD. THUS...THE FORECAST PHILOSOPHY WILL EMPHASIZE
MODEL CONSENSUS AND CONTINUITY TO THE FULL EXTENT POSSIBLE...WITH
GLOBAL ENSEMBLE MEANS USED TO CONSTRUCT THE PRELIMINARY
PRESSURES/FRONTS FOR DAYS 3/7...INCLUDING THE ECMWF ENSEMBLE
MEAN/GEFS MEAN/NAEFS BCMEAN.

THE MAIN DIFFERENCE WITH THE MEANS INVOLVES THE ORIENTATION AND
STRENGTH OF THE MEAN RIDGE OVER THE SOUTHEAST BY DAY 7...WITH THE
ECMWF ENSEMBLE MEAN MORE AMPLIFIED AND STRONGER THAN THE
GEFS/NAEFS. WOULD NORMALLY PLACE GREATER EMPHASIS ON THE ECMWF
ENSEMBLE MEAN IN SUCH A CASE DUE TO ITS HIGHER RESOLUTION AND
GREATER NUMBER OF MEMBERS CONSTITUTING ITS MEAN.
HOWEVER...TELECONNECTIONS WITH THE LARGE NEGATIVE HEIGHT ANOMALY
NEAR HUDSON BAY SHOWS BETTER AGREEMENT WITH THE GEFS/NAEFS.
THUS...REDUCED THE ECMWF ENSEMBLE MEAN CONTRIBUTION TO ABOUT 50
PERCENT. ALSO MANUALLY INCORPORATED DETERMINISTIC DETAIL IN THE
PROGS WHERE CLUSTERING OF SOLUTIONS EXISTED. HOWEVER...THIS WAS
MINIMAL...WITH CONFIDENCE BELOW AVERAGE FOR THE ENTIRE PERIOD.

JAMES

[djmikey]

I checked this morning and Accuweather has rain/snow forecasted for the Beaumont, TX area on the 4th. I know it will likley change later today, but all in all intresting that these sites are now starting to forecast snow/rain for areas of SETX. Lastnight, they had ice for our area. Hmmm....

[Portastorm]

Below is the 8-10 day depiction of the general weather pattern at the 500mb level. On the left is the European and the GFS is on the right. I will say this, should the European verify here, this is a classic pattern for winter weather in the Southern Plains. You probably couldn't draw up a better map for it. We shall see ..



Uploaded with ImageShack.us

[HockeyTx82]

While walking into the work this morning, at about 7:58AM here in Denton, there was a mixed bag of frozen precip that was coming down for about 2 min. Is that considered a bust on the forecast?

[natlib]

The snow was a no show in San Angelo last night. I woke up to beautiful clear skies and dry ...........

This my friends is unfortunately what happens when snow is forecast in my area.

Fingers and toes will now be crossed for next week.

[txagwxman]

Sorry was looking at a wrong panel (need glasses).

ECMWF still sleet on Tue DFW, but ends quickly.

And RAIN for the Houston marathon.

[Tireman4]

Sorry was looking at a wrong panel (need glasses).

ECMWF still sleet on Tue DFW, but ends quickly.

And RAIN for the Houston marathon.

Rain is sorta ok, but torrential....LOL

[orangeblood]

The GFS ensembles have been really consistent with the system early next week and still look really good.

[Brandon8181]

The GFS ensembles have been really consistent with the system early next week and still look really good.

Yup, this is really gaining my confidence..

[Parker_County1]

Here in Weatherford we are getting more precip reaching the ground now than the models were forecasting last night. Unfortunately it is just rain. 35°. There is a warm layer somewhere.

[gboudx]

Here in Weatherford we are getting more precip reaching the ground now than the models were forecasting last night. Unfortunately it is just rain. 35°. There is a warm layer somewhere.

Same here in Richardson. Very light sprinkles, 40°.

[srainhoutx]

Impact Weather has a new updated video that is well worth watching...

http://www.youtube.com/impactweather

[gboudx]

That's the same map, and pretty much the same thing he said yesterday. Nothing we don't already know. Wait and see.