Texas winter wx thread (2009-2010)

[wxman57]

Did anyone look what the GFS is doing with surface temps? I plotted a meteogram and it has DFW in the 40s during the precip next Tue-Thu:

http://myweb.cableone.net/nolasue/dfwgfs6zfeb19.gif

Im not sure what you're seeing but it shows temps in the low 30's Tuesday its Thursday/Friday where it shows temps in the 40's...

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

Look again - the Tuesday impulse is weak with little or no precip (green bars on the bottom). The big precip event is Thu-Fri (low in Gulf). During all the precip, the 06Z GFS has temps in the 40s in Dallas. Clearly, it's still having a big problem with the pattern and is not to be trusted too much.

All the models are having major problems with this pattern. Remember a week ago that the BIG EVENT was going to be today? Then it switched to maybe Monday-Tuesday. Now it's Wednesday to Friday of next week.

The latest Euro has the 850mb 0C line way up in Oklahoma:
http://www.meteo.psu.edu/~gadomski/ECMWF_0z/f168.gif

Only cold rain across Texas. At least, that's all I can see with the low-res version online with charts 24 hours apart. I don't think it's right, either.

Maybe by Sunday or Monday we'll start getting more model agreement on next week's event(s). For now, I wouldn't trust any of the models for details as to precip amounts and types.

[srainhoutx]

The updated Prelim Extended HPC Disco offers a descent explanation of all the issues...

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
855 AM EST FRI FEB 19 2010

VALID 12Z TUE FEB 23 2010 - 12Z FRI FEB 26 2010

UPDATED PRELIM PROGS MADE ONLY COSMETIC CHANGES TO THE EARLY
RELEASE. A STRONG BLOCKING 500MB PATTERN AT HIGH
LATITUDES...FEATURING HIGHS OVER WRN CANADA AND THE DAVIS
STRAIT...WILL SLOWLY BEGIN TO WEAKEN OVER WRN NOAM WHILE THE DAVIS
STRAIT BLOCK HOLDS THRU THE END OF THE MEDIUM RANGE PERIOD. WHILE
THERE IS DECENT AGREEMENT ON THE DAY 3 SYS AFFECTING THE OH
VLY/MID ATLANTIC...UNCERTAINTY INCREASES DRAMATICALLY FOR THU/FRI
DAYS 6-7. ENSEMBLE SPAGHETTI PLOTS SUGGEST THAT THE DETERMINISTIC
00Z/19 ECMWF/CANADIAN SOLUTIONS...WHICH SHOW SIGNIFICANT ENERGY
OVER THE SWRN CONUS FOR THU DAY 6....ARE OPPOSED TO THE GFS/UKMET
FAMILY OF SOLUTIONS. THE GFS/UKMET FAMILY OF SOLUTIONS HAS THE
MAIN SRN STREAM SYS CROSSING THE GULF COAST STATES THU....MORE IN
LINE WITH YESTERDAYS ECMWF RUNS...AND PLAYS UP ENERGY DROPPING S
OUT OF A NRN CANADIAN VORTEX. THIS SUGGESTS POSSIBLE PARTIAL
PHASING OF THE SRN STREAM IMPULSE WITH THE NRN STREAM LATER
THU/FRI. THE GFS/UKMET FAMILY OF SOLUTIONS AND ENSEMBLE MEAN
CHARTS FAVORS NRN STREAM DOMINANCE FOR THU/FRI DAYS 6-7...AND
PLACE SOME KIND OF DEEPENING LOW PRES OFF THE MID ATLANTIC OR NEW
ENG COASTS. A MORE PERFECT PHASING OF NRN AND SRN STREAMS WOULD
ALLOW LOW PRES TO DEEPEN FARTHER DOWN THE COAST OFFSHORE...WITH
THE DISTANCE OF THE TRACK OFFSHORE A CRITICAL FACTOR.


A SLIGHTLY RETROGRESSIVE POSITIVE ANOMALY MOVING FROM THE DAVIS
STRAIT INTO NORTHEAST CANADA FAVORS A QUASI-STATIONARY CYCLONE
NEAR THE NORTHEAST...WHICH SHOULD KEEP NEW ENGLAND WET/SNOWY FROM
TUESDAY ONWARD. ANOTHER DEEP CYCLONE IS EXPECTED TO REMAIN
OFFSHORE THE PACIFIC NORTHWEST THROUGH THE MEDIUM RANGE PERIOD.
THE MODELS AGREE ON THESE IDEAS...THOUGH THERE ARE DETAIL ISSUES.
A COMPROMISE/BLEND OF THE 00Z GFS/00Z ECMWF SUFFICED THROUGH
WEDNESDAY NIGHT...BEFORE THE 00Z ECMWF DIVERGED FROM THE ENSEMBLE
ENVELOPE THEREAFTER WITH THE LOWS NEAR NEW ENGLAND AND OFFSHORE
THE PACIFIC NORTHWEST. FROM THURSDAY MORNING ONWARD...USED A
COMPROMISE OF THE 00Z GFS/00Z GEFS MEAN...WHICH MAINTAINED
REASONABLE CONTINUITY. LAKE EFFECT SNOWS ARE EXPECTED FROM
WEDNESDAY ONWARD IN THE CYCLONIC FLOW ON THE BACKSIDE OF THE
NORTHEASTERN VORTEX...WHILE PACIFIC COLD FRONTS WEAKENING AS THEY
APPROACH THE PACIFIC NORTHWEST SHOULD BRING LIGHT TO MODERATE
RAINS/ELEVATED SNOWS INTO THE REGION. THE MAIN THEME OF THIS
WINTER PERSISTS...WITH COLDER THAN NORMAL TEMPERATURES EXPECTED
EAST OF THE ROCKIES AND MILD TO WARM TEMPERATURES EXPECTED ACROSS
CALIFORNIA AND THE SOUTHWEST.

ROTH/FLOOD

00Z GFS Ensemble Members...

http://www.meteo.psu.edu/~gadomski/ENSP ... opnew.html

[jasons2k]

Morning update from Jeff:

After a warming trend this weekend…it will return to cold next week.

Big differences continue in the extended with wide varying forecast solutions between liquid and frozen.


Discussion:

Will tackle the near term issues first and then make some attempt at next week although the theme is very low confidence and the sad fact that any forecast for next week at this point is bound to be wrong to some degree.

Upper level short wave tracking over S TX and the NW Gulf this morning with light to moderate rains from Galveston Island to Victoria and southward. Looking at radar rainfall estimates shows some decent amounts around Matagorda Bay, but ALERT data from LNRA suggests otherwise with max totals noted so far of .16 of an inch at Lake Texanna. Radar is likely overestimating rainfall in this area although a few locations may total up to .5 of an inch this morning from Port Lavaca to Palacios southward. This short wave will be east of the area by late afternoon with all rainfall ending and pushing eastward. Low level warm air advection will continue with no air mass change with this feature. Dewpoints slowly rise toward the mid 50’s overnight and a few models are showing a strong sea fog event. Feel dewpoints will not greatly exceed nearshore water temps. Tonight so sea fog should not be extensive. Warm air advection increases on Saturday with dewpoints rising toward 60. May see a few showers develop with the increasing moisture regime and by this time dewpoints will likely exceed nearshore water temps. Leading to sea fog. Will likely sock in the nearshore waters and bays during the day on Saturday and then spread the thick soup inland Saturday night…although not sure how far inland the fog makes it. Highs will reach 70 on Saturday and the lower 70’s on Sunday.

Sunday still looks to be stormy ahead of the next strong cold front. As suspected yesterday, capping to the SW over the CRP/VCT area may encompass more of SE TX than the models are showing especially since boundary layer winds turn SW ahead of the pre-frontal trough…usually an unfavorable convective profile for SE TX. However models are in decent agreement that the air mass will become increasingly unstable during the day with showers and thunderstorms developing in the warm sector ahead of the pre-frontal trough and along the trough itself. Will put the best chances along and E of I-45 with this area showing the greatest severe threat. Will need to watch trends Saturday and early Sunday as this threat could be expanded as the event draws nearer. Also as mentioned yesterday, the models are likely a little aggressive on the amount of instability with this system, so any severe weather should be isolated.

Next week:

The problems begin with the passage of the strong old front Sunday evening with the GFS now much colder and wetter for early next week and the past consistent ECMWF having flipped 180 from yesterday morning on its 00Z run to a much drier and warmer forecast with the GFS flipping 180 the other way…go figure! UKMET remains stable and in support of the colder/wetter solution along with several of the ensemble members. The problems with the models appear to be in their handling of the energy coming into the US west coast and the developing split flow aloft.

With all this on the table and considering up until last evening the ECMWF was favorable for wet and cold…with trend in that direction and wait for the 12Z runs this morning to go flip flopping all around…reminds me of hurricane season! Following the colder/wetter solution brings rain back into the forecast rapidly by late Monday-Wed of next week. GFS forecast soundings and critical thickness values support P-type issues across much of TX if in fact this event pans out. I am more confident on cutting temperatures than adding frozen precipitation to the forecast. For now will go with highs in the 50’s Monday and then the 40’s Tuesday and Wednesday and they may need to be knocked down even more into the 30’s for Tues/Wed. As for precipitation, will bring rain into the picture overnight Monday and keep it all liquid into Tuesday and then bring RA/SN mix into our NW counties Tuesday afternoon. If the GFS is in fact on the right page and the ECMWF trends back toward its older solutions then RA/SN mix will be pushed southward and all SN will be possible over portions of the area with some accumulations. Needless to say yet again…the forecast for next week is extremely low confidence.

[txagwxman]

Did anyone look what the GFS is doing with surface temps? I plotted a meteogram and it has DFW in the 40s during the precip next Tue-Thu:

http://myweb.cableone.net/nolasue/dfwgfs6zfeb19.gif

Im not sure what you're seeing but it shows temps in the low 30's Tuesday its Thursday/Friday where it shows temps in the 40's...

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

Look again - the Tuesday impulse is weak with little or no precip (green bars on the bottom). The big precip event is Thu-Fri (low in Gulf). During all the precip, the 06Z GFS has temps in the 40s in Dallas. Clearly, it's still having a big problem with the pattern and is not to be trusted too much.

All the models are having major problems with this pattern. Remember a week ago that the BIG EVENT was going to be today? Then it switched to maybe Monday-Tuesday. Now it's Wednesday to Friday of next week.

The latest Euro has the 850mb 0C line way up in Oklahoma:
http://www.meteo.psu.edu/~gadomski/ECMWF_0z/f168.gif

Only cold rain across Texas. At least, that's all I can see with the low-res version online with charts 24 hours apart. I don't think it's right, either.

Maybe by Sunday or Monday we'll start getting more model agreement on next week's event(s). For now, I wouldn't trust any of the models for details as to precip amounts and types.

Impulse weak? GFS has 3-4" of snow south of DFW on Tuesday. The GFS is plenty cold for snow on Tue, it is the other models that we are having problems (ECMWF/GEM).

[msstateguy83]

THIS IS FROM A GFS RUN EITHER SAT/SUN OF LAST WEEK SHOWING THIS UPCOMING STORM....

does anyone remember what the gfs was saying late last week??? the 'TRENDS' have been there on/off but THEY have been there
I feel this run from either sat/sun last week shows what is MOST LIKELY, key word most likely to happen for early to mid part of
next wk.. i think we will likely see a further northward track then models currently showing with most of the winter precip up
along the redriver region with some significant accumulations in far northern,nw tx up into sw,central ok... for the metroplex yes
some winter precip maybe 4-6" inches but anything more then that will be to the north and south of the metroplex i expect just
a cold rain.

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org. For official information, please refer to NWS products.

[txagwxman]

6z GFS is cold enough. That is over Waco, TX.

Just need other models to come through. Hopefully today's 12z runs will provide more insight.

[Ntxw]

Msstateguy83, I don't think it will be that far north. Look at the trough, and vortex up in Canada, and storm exiting the East coast. Those should prevent anything beyond southern Oklahoma really from what I see. If anything it could be even more suppressed.

[Nederlander]

yea I agree.. this is looking more like a central tx storm to me.. unfortunately i dont see it getting as far south as I would like it to, but anything can happen..

[Ntxw]

JB this morning thinks that Dallas could break it's seasonal record. Mentioning el nino, cold PDO etc and so forth.

[WacoWx]

6z GFS is cold enough. That is over Waco, TX.

Just need other models to come through. Hopefully today's 12z runs will provide more insight.

did somebody say Waco??!!!!?!?!?! and did someone else say more of a Central Texas storm???? (crossing fingers, petting beard, etc.)

Our local met is saying 38 with a 20% chance of rain/snow. Better than the 50's previously!

[Ntxw]

6z GFS is cold enough. That is over Waco, TX.

Just need other models to come through. Hopefully today's 12z runs will provide more insight.

did somebody say Waco??!!!!?!?!?! and did someone else say more of a Central Texas storm???? (crossing fingers, petting beard, etc.)

Our local met is saying 38 with a 20% chance of rain/snow. Better than the 50's previously!

From what it looks, 6z painted Waco-ish smack dab in the middle, I'd wait for 12z before getting too excited though.

[Nederlander]

From what it looks, 6z painted Waco-ish smack dab in the middle, I'd wait for 12z before getting too excited though.

12z is running....

[Weatherdude20]

I think the bulk of this event will be centered from Central Texas up into North Texas, and parts of West Texas.

With impacts Ranging from Moderate-Heavy, Widespread impacts could occur mainly because of lack of prep, and experience, but for now Iam staying conserveative on snowfall accumulations as well. The potential for the Snow profiles to be signifigant on effects wise is high due to cross polar flow. Please note that we have multiple factors that we are depending on for this potential Winter Storm to be Stronger/Weaker.

EDIT UPDATE: There could also be widspread snowfall all over the region with a good 2-4" across the Metro for now.IMHO

[gboudx]

JB this morning thinks that Dallas could break it's seasonal record. Mentioning el nino, cold PDO etc and so forth.

Aren't we about 2" shy?

[Ntxw]

JB this morning thinks that Dallas could break it's seasonal record. Mentioning el nino, cold PDO etc and so forth.

Aren't we about 2" shy?

1.9 I believe, but yeah I'd say 2 for aesthetics . And for those waiting for a southern track, it doesn't necessarily mean the chances are better for snow\ice (though usually storms ride the gradient meaning cold air is further south than expected), it could also mean MORE heavy rain versus light cold rain. Key would be how deep, cold the air is coming in. Keep an eye on high pressures north of the low.

[WacoWx]

6z GFS is cold enough. That is over Waco, TX.

Just need other models to come through. Hopefully today's 12z runs will provide more insight.

did somebody say Waco??!!!!?!?!?! and did someone else say more of a Central Texas storm???? (crossing fingers, petting beard, etc.)

Our local met is saying 38 with a 20% chance of rain/snow. Better than the 50's previously!

From what it looks, 6z painted Waco-ish smack dab in the middle, I'd wait for 12z before getting too excited though.

too late!

[msstateguy83]

i will say this there is LOTS of details to sort out but i have been looking at next wk for awhile now, i feel someone is gonna get blasted with lots of snow just details need to be worked out but IMO iam sticking w/a northward track but we will see..

[srainhoutx]

You can already see that a supressed solution is coming via the 12Z GFS. The NAM shifts everything S in CA and it appears the GFS is following the trend as well.

[gboudx]

great. I cant wait to miss another day of school and finish on june 7th, 4 days after the original last day of school : (

As much as I love snow, I really would like not to miss another day of school. 1 foot is enough for this winter...we dont need another half or more...but I know its going to happen just cuz i dont want it to

How many days have you missed this winter? My kids have only missed 1, and they have to make it up on 4/5, the day after Easter. Typically, the ISD's will want to make up the days before TAKS testing starts.

BTW, I told my kids that they may miss another day next week because of snow and they weren't happy. They don't want to make up anymore days. They had fun playing in it, but got tired of the snow after about an hour. True southerners.

[Portastorm]

You can already see that a supressed solution is coming via the 12Z GFS. The NAM shifts everything S in CA and it appears the GFS is following the trend as well.

Yep srainhoutx, even through 78 hrs, the 12z GFS is looking a lot like its 0z run. I like the trend!