Texas winter wx thread (2009-2010)

[srainhoutx]

Aside from the WPAC, it's been a little slow on s2k today. I found the thread with all the interesting stuff!

I hope you guys in North Texas get some snow, but are any of these models that I do not believe this far out showing anything remotely interesting reaching us way down here?

Keep an eye on the Mid December time frame SG. Remember last year around the 10th of December? I know wxman57 has mentioned that freezing temps are possible around the 7th-9th in SE TX. Also it will be interesting to watch the Sub Tropical Connection as the coldest air finally makes it's way south. Let's just hope it's not ice.

[ntxweatherwatcher]

I hope we see some wintery precip here, cold rain is just awful!!

[gboudx]

From Larry Cosgrove this evening.

Discussion
(Relevant Graphics Follow The Text)

With the four-day Thanksgiving holiday weekend fast approaching (and with it overeating and overspending....LOL), most Houstonians would prefer a quiet weather pattern to ease travel for themselves and loved ones. For the most part, the atmosphere should cooperate. But there are some flies in the ointment that you should know about.

A cold front and trough will pass through southeastern Texas by Tuesday afternoon, accompanied by showers and thunderstorms. The attendant trough complex will deepen appreciably as it passes through the Mississippi Valley on Wednesday and Thanksgiving Day, tapping into some very chilly air from Canada. And while I do not expect the effects of this particular system to last long (it is a progressive 500MB longwave pattern, at least for now), you WILL feel cold headed out during the evenings of Wednesday and Thursday. Frost is a very real possibility in Texas as far south as parts of Waller and Montgomery counties by daybreak on Friday morning.

And just because temperatures will warm up on Saturday and Sunday does NOT mean Texans are in for a balmy trend in the weather! Far from it, in fact, as all of the numerical models (following up on earlier ensemble forecasts) are detailing the development of a powerful winter storm over NM and W TX by the morning of November 29. Heavy rain, gusty wind and severe thunderstorms loom as possibilities in Houston on Sunday afternoon and night, followed by a howling Blue Norther in play by next Monday morning! The rain-snow line is predicted by the GFS and ECMWF schemes to get as far south as a Killeen.....Corsicana....Marshall arc before the storm heads into the Great Lakes during the middle of next week.

Oh the weather outside is frightful...yes, they might get a white end to November in Dallas and Tyler!

[iorange55]

AHHH LARRY! Don't feed my dreams. Frank Strait I believe is his name, on accuweather. He's making it seem like we shouldn't get excited about snow YET. He said the north needs to cool down a little, and we might see some towards the end of December.



We'll see.

[cheezyWXguy]

The 0z is quite a bit warmer this time, not even putting NTX below freezing at night during the event, with what appears to be a weaker high pressure in association with the airmass, as well as less post-frontal moisture. This is quite a contrast from earlier runs, and only further proves the uncertainty of mid-long range period forecasting.

Im not ready to buy into a winter weather scenario yet, but I also have trouble believing that the lows will be warmer after the passage of the stronger front next week, than the weaker front coming though in a couple of days, when lows will be hovering near the freezing mark.

[iorange55]

The GFS 0z kind of backed off a little, but it seems to me that the latest ECMWF run still looks very interesting. Then again it's been over a year, and I still have trouble reading that one.

[rainman31]

It looks like temps have gone up considerably from yesterday for the next 15 day.

[iorange55]

They're about to go down with the new GFS 06 coming out. It's brought back snow, and colder temps.

[Portastorm]

... and that's what I was trying to say yesterday, gang, that the models (especially the GFS) will struggle with this pattern. You see the variability at play in the operational runs.

Here is the 500mb pattern for Dec. 4th from both the 0z GFS and 0z Euro ... you can see how dramatically different they are. The GFS is much warmer and zonal while the Euro paints a cold, blustery picture.

GFS



The European

[srainhoutx]

HPC is leaning strongly toward the ECMWF Solution as of now...

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
253 AM EST TUE NOV 24 2009

VALID 12Z SAT NOV 28 2009 - 12Z TUE DEC 01 2009


STAYED THE COURSE WITH THE ECMWF FOR THE PRELIMINARY FRONTS AND
PRESSURES FOR DAYS 3 THROUGH 7. THE ECMWF HAS BEEN LOCKED ON A
LONGWAVE SIGNAL FOR THE FIRST HALF OF THE UPCOMING MEDIUM RANGE
PERIOD FOR SEVERAL CYCLES NOW...WITH A FAR MORE VOLATILE ARRAY OF
SOLUTIONS FROM THE OTHER NUMERICAL MODELS INCLUDING THE GFS...GEM
GLOBAL...AND UKMET. THE STRENGTH OF THE CYCLONE COMING INTO THE
PACIFIC NORTHWEST LATE IN THE SHORT RANGE PERIOD IS STILL IN
PLAY...WITH THE GEM GLOBAL INDICATING NO LOW WHATSOEVER. PREFER
TO RELY ON THE DETAILS OF THE ECMWF WITH THIS SYSTEM...MOSTLY DUE
TO ITS STRONG PERFORMANCE IN GENERAL. WHERE...WHEN...AND IF A
SYSTEM CLOSES OFF OVER THE TENNESSEE VALLEY BY DAYS 6 AND 7 IS
PERHAPS THE MURKIEST ASPECT OF THE FORECAST...WITH THE
INCORPORATION OF A SIZABLE CHUNK OF THE MOST RECENT EC ENSEMBLE
MEAN AT THAT RANGE HOPEFULLY MITIGATING THE UNCERTAINTY.


CISCO

[HockeyTx82]

From NWS in Ft. Worth, TX.

SATURDAY THROUGH TUESDAY...GFS/ECMWF ARE CONSISTENT IN BRINGING A
DEEP TROUGH THRU THE WESTERN CONUS WITH A STRONG PIECE OF ENERGY
EJECTING OUT NORTHEAST THRU TX DURING THIS PERIOD. FOR SATURDAY
AND INTO SUNDAY MORNING BOTH MODELS HAVE SOUTHWEST FLOW ALOFT OF
THE SOUTHERN PLAINS WHICH SHOULD PROMOTE GOOD CYCLOGENESIS NEAR
THE TX/OK PANHANDLES AND START BRINGING GULF MOISTURE BACK INTO
THE REGION. AFTER SUNDAY MORNING THE MODELS BEGIN TO DIVERGE QUITE
A BIT AS THE GFS KICKS THE STRONGEST PIECE OF ENERGY THRU TX
SUNDAY NIGHT WHILE THE ECMWF HOLDS THIS ENERGY BACK UNTIL CLOSER
TO MONDAY NIGHT. WHENEVER THIS ENERGY KICKS OUT...THIS WOULD SEEM
TO COINCIDE WITH THE BEST CHANCE FOR PRECIPITATION WITH THE STRONG
ASSOCIATED LARGE SCALE FORCING FOR ASCENT AND THE PASSAGE OF A
STRONG COLD FRONT. THE SLOWER TIMING OF THE ECMWF WOULD ALLOW
DEEPER GULF MOISTURE TO ENTER THE REGION LIKELY INCREASING THE
OVERALL COVERAGE AND INTENSITY OF PRECIPITATION WHEN THE FRONT
ROLLS THROUGH. A SLOWER SOLUTION WOULD ALSO INCREASE THE CHANCES
OF ISOLATED TO SCATTERED TSTM ACTIVITY OUT AHEAD OF THE FRONT. FOR
NOW THE FORECAST REPRESENTS A BLEND OF THESE TWO SOLUTIONS WITH
POPS IN THE FORECAST FROM SATURDAY NIGHT THROUGH MONDAY. IF THE
ECMWF DISPLAYS MORE CONTINUITY POPS WILL LIKELY HAVE TO BE
EXTENDED IN TIME...WHEREAS THE GFS WOULD INDICATE A QUICKER END TO
PRECIP CHANCES AS DRY AIR MOVES IN BEHIND THE FRONT BY MONDAY
AFTERNOON. WITH TOO MUCH UNCERTAINTY IN THIS PERIOD DID NOT
INCREASE POPS OUT OF THE 30 PERCENT RANGE...HOWEVER ONCE
CONFIDENCE INCREASES IN TIMING OF THIS UPPER LVL SYSTEM HIGHER POPS
WILL LIKELY BE NEEDED. CAVANAUGH

And for what it is worth, this morning when I went to go and catch the bus it felt fairly cold out there. For some reason the cold just seem to cut right through me.

[snow and ice]

EURO has nice pocket of cold air in the upper levels next Wednesday over north Texas, with a strong surface feature near the Mississippi River. The EURO has been consistent with this over the past 3 days, just varying the timing a little from run to run.

http://raleighwx.easternuswx.com/models ... TNA192.gif

[snow and ice]

... and that's what I was trying to say yesterday, gang, that the models (especially the GFS) will struggle with this pattern. You see the variability at play in the operational runs.

Here is the 500mb pattern for Dec. 4th from both the 0z GFS and 0z Euro ... you can see how dramatically different they are. The GFS is much warmer and zonal while the Euro paints a cold, blustery picture.

GFS



The European

[url=http://img130.imageshack.us/i/geopotential3250032hpan.gif/][img]http:
//img130.imageshack.us/img130/4431/geopotential3250032hpan.th.gif[/img][/url]

Actually, the Ensembles and the EURO are in very good agreement for next week.

6z Ensembles:
http://www.meteo.psu.edu/~gadomski/ENSH ... /f240.html

[srainhoutx]

EURO has nice pocket of cold air in the upper levels next Wednesday over north Texas, with a strong surface feature near the Mississippi River. The EURO has been consistent with this over the past 3 days, just varying the timing a little from run to run.

http://raleighwx.easternuswx.com/models ... TNA192.gif

This is the feature to watch regarding any wintry precip for TX. We know that Cold Core Upper Lows are a forecasting nightmare and often over perform. Interesting weekend and early next week for Parts of TX, OK, AR, MO, and KS.

[Portastorm]

The 12z GFS is looking a lot more like the 0z Euro next week and beyond. Very cold looking with some possible winter precip events.

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fpc.shtml

[cheezyWXguy]

The 12z GFS is looking a lot more like the 0z Euro next week and beyond. Very cold looking with some possible winter precip events.

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fpc.shtml

I dont follow.
I see some cold in the long range, but a warmer drier front in about 6 days than the model was showing yesterday. And no winter precip
sigh....

[snow and ice]

The 12z GFS is looking a lot more like the 0z Euro next week and beyond. Very cold looking with some possible winter precip events.

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fpc.shtml

I dont follow.
I see some cold in the long range, but a warmer drier front in about 6 days than the model was showing yesterday. And no winter precip
sigh....

Once you get past 3-5 days the operational GFS should only be used for general trends not specifics. It's much better to use the EURO or the Ensembles when looking in the long range. Speaking of long term trends, all the models are strongly suggesting a trough in the central and southern US from the first through mid December. This favors cyclogenesis in the GOM, and it's just a matter of time before one of these systems meshes with cold air that will becoming down from the north. Who will get what can only be determined once you get to within a couple days of the storm.

[HockeyTx82]

So is it looking more and more that the cold and winter stuff will once agian miss us early next week? I realize we are a few days out, but from what I remember last year this stuff always happened like this. Crazy cold forecast then nothing.

[rainman31]

It happens every year, the models always show a real strong cold surge, then it's not as strong.

[HockeyTx82]

It happens every year, the models always show a real strong cold surge, then it's not as strong.

Last winter was the first time I followed any kind of a website chartroom in regards to weather, it was this one. I caught on quickly that long range forecast, while fun to talk about, never seem to hold up. Oh well perhaps old man winter will surprise us this year. I still wish Harold Taft was around. Anyone on here remember him from the Dallas station Ch 5 NBC? He was the best, IMO. I swear once he forecasted snow when no other local mets would and by gosh it snowed on the day he said it would. Crazy, almost as if he knew something the others did not and that he had some kind of connection or control over the weather. I guess technically winter does not start until the end of December so we still have plenty of chances.