Texas Winter 2010-2011

[Rgv20]

^Yeah I know my bad, just got overzealous cause it shows half of tx cover in snow.....not much of it but its a start

[funster]

^ You shouldn't post the ECMWF charts. I think it would be wise to remove it. Euro does show a significant snow event for Texas, and possibly yet another behind it.

True probably should not if Accuweather owns it. Technically, this is also a copyright violation, which was posted by one of the moderators. -> viewtopic.php?f=22&t=19890&start=0&st=0&sk=t&sd=a

[BigB0882]

I can't imagine that large of an area would have snow and no one would have more than an inch. Seems unreasonable but I like the trends we have going.

[funster]

The snow threat is fading http://wxweb.meteostar.com/sample/sampl ... ?text=KDAL

Looked much better a couple days ago

[Ntxw]

^Yeah I know my bad, just got overzealous cause it shows half of tx cover in snow.....not much of it but its a start

It's no problem! Just wanted to point it out . That snow map you looked at is deceptive. Euro snow charts are similar to the RUC. The 1 inch is not what is on the ground but what is falling at that exact time, that's what I've concluded to. Show's about 3-6 inches worth of qpf but we all know that's fatal this far out. Euro isn't reliable for something like that at this range. It's known to underestimate dramatically longer out . Verbatim.

[iorange55]

The snow threat is fading http://wxweb.meteostar.com/sample/sampl ... ?text=KDAL

Looked much better a couple days ago

I disagree.

[funster]

The snow threat is fading http://wxweb.meteostar.com/sample/sampl ... ?text=KDAL

Looked much better a couple days ago

I disagree.

It showed like almost half an inch of precip during below freezing temps before. Now it just shows lame light precip. Chance of storm is decreasing -- We will probably get nothing and this could even be the last shot before winter ends.

[iorange55]

The snow threat is fading http://wxweb.meteostar.com/sample/sampl ... ?text=KDAL

Looked much better a couple days ago

I disagree.

It showed like almost half an inch of precip during below freezing temps before. Now it just shows lame light precip. Chance of storm is decreasing -- We will probably get nothing and this could even be the last shot before winter ends.

You are paying waaaaaaaay too much into details on that site. It's going to change a lot each run. Two or Three days ago I don't believe we had the model support that we do now. Most of the models show some type of storm now and the GFS still shows a big storm. The details are the only thing going all over the place, which is expected this far out.

[funster]

Ok. Hope so iorange55. Ill stop watching the meteostar update by update :-D

[Ntxw]

Ok. Hope so iorange55. Ill stop watching the meteostar update by update :-D

Meteostar is raw data from the GFS. It's whacky, you shouldn't bother even paying attention to it much. Unless you're using it for the 2-4 day range.

[txagwxman]

12z ECMWF much more bullish for DFW Monday/Tuesday with sleet/snow/fz rain.

Houston just too far south for now.

[Tireman4]

12z ECMWF much more bullish for DFW Monday/Tuesday with sleet/snow/fz rain.

Houston just too far south for now.

As you have stated....never say never. LOL

[DentonGal]

12z ECMWF much more bullish for DFW Monday/Tuesday with sleet/snow/fz rain.

Houston just too far south for now.

Oh goodie!!!

[Portastorm]

Snippet regarding next weekend from the afternoon AFD out of NWSFO Fort Worth. They say "all hail King Euro!":

DIFFERENCES ON SYSTEMS REALLY GET REALIZED DAY 7/BEYOND AS THE GFS
ADVERTISES A STRONG SYSTEM ARRIVING SUN/MON IN THE SRN STREAM/
CONVERGENT UPPER FLOW OVER TX...WHILE THE ECMWF IS WEAKER/SLOWER/
AND FURTHER SOUTH WITH THIS FEATURE WITH BULK OF ANY PRECIPITATION
POTENTIAL REMAINING WELL TO THE SOUTH OF OUR AREA. AS STATED...WE`RE
ON BOARD WITH THE ECMWF FOR THE TIME BEING AND WITH IT`S BETTER
TRACK RECORD BEYOND DAY 5 IN MOST CASES.

[srainhoutx]

Midland/Odessa:

THE GENERAL PATTERN THAT WE/VE BEEN IN CAN BE CHARACTERIZED AS A
COLD PROGRESSIVE. FROM A PACIFIC NORTH AMERICAN PATTERN OR
TELE-CONNECTIONS PERSPECTIVE THE W COAST RIDGE HAS FAVORED A
MERIDIONAL MID LEVEL COMPONENT AND THUS FREQUENT COLD FRONTS.
FREQUENCY OF COLD FRONTS/SOURCE REGIONS IN PART ARE LIMITING THE
CHANCE OF SIG PRECIP THIS FAR W AS THERE HAVE BEEN ONLY SMALL
WINDOWS FOR MSTR TO RETURN AHEAD OF FRONTS...NOT SO MUCH FARTHER SE
INTO THE STATE. FURTHER THE POSITIVE PNA PATTERN OF LATE IS IN
ALIGNMENT WITH A NEGATIVE PHASE OF THE ARCTIC OSCILLATION...THUS
AIDING THE COLD PART OF THE PROGRESSIVE PATTERN. USING 6-10 DAY
AND 8-14 DAY 5H ANOMALY CHARTS THE POSITIVE PNA PATTERN (RIDGE IN
THE W) SHOWS VERY LITTLE CHANGE IN THE AMPLITUDE OF THE PATTERN.
MEANWHILE THE ENSEMBLE RUNS OF THE ARCTIC OSCILLATION DO SHOW A
TREND UPWARD WHILE THE DETERMINISTIC MODELS GFS/ECMWF HINT THAT
MID LEVEL RIDGE WILL BE A LITTLE FARTHER W. ALL TO SAY THAT THERE
IS NOT A STRONG SIGNAL THAT THE PATTERN WILL CHANGE WITHIN THE
NEXT 2 WEEKS.

Corpus Christi:

BEYOND FRIDAY THE NEXT QUESTION IS HOW THE UPPER LOW OVER THE BAHA
REGION WILL LIFT OUT AND WHEN. THE ECMWF LOOSES THE SYSTEM ALL
TOGETHER WHILE THE GFS/CANADIAN MODELS BEGIN TO EJECT THE SYSTEM AND
BRING IT ACROSS NE MEXICO TOWARD SOUTH TX FRI NGT/SAT. MOISTURE AND
FORCING LOOKS BETTER WITH THIS FEATURE THUS ADDED 20/30% POPS.
MEANWHILE...THE UPR PATTERN BEGINS TO BUCKLE WITH A STRONG MID/UPR
LVL RIDGE BUILDING BACK OVER WESTERN CANADA AND A DEEP COLD TROUGH
BECOMING AMPLIFIED OVER HUDSON BAY. SFC TEMPERATURE READINGS THE PAST
COUPLE DAYS ACROSS MUCH OF CENTRAL CANADA HAVE BEEN FRIGID...HOVER
IN THE -20 TO -50 DEG F RANGE. IF THIS TROUGH AMPLIFIES...WE COULD
SEE THE COLDEST AIRMASS OF THE SEASON BEGIN TO SURGE INTO THE NATION
EAST OF THE ROCKIES...WITH THE INITIAL EDGE OF THE FRONT REACHING
SOUTH TEXAS MONDAY AFTN. THE AIRMASS WOULD MODIFY SIGNIFICANTLY
BEFORE REACHING SOUTH TEXAS BUT RAW GFS SFC TEMPS INDICATE HIGHS IN
THE MID 20S-MID 30S ACROSS THE CWA ON TUE. (HAVEN`T SEEN TEMPS THIS
COLD IN CANADA ALL SEASON UNTIL NOW) AGAIN THERE IS CONSIDERABLE
UNCERTAINTY SO WE`LL HAVE TO WATCH THIS CLOSELY AS TIME DRAWS
CLOSER. COULD BE SOME POST FRONTAL PCPN MONDAY AS BOTH THE
GFS/ECMWF PROG A FAIRLY DEEP LAYER OF MOISTURE OVER SOUTH TEXAS AND
AND UPR LVL S/W ENERGY TO PROPAGATE OVER THE REGION.

[Portastorm]

As has been alluded to by our pro mets, folks shouldn't get too wrapped around the axle about surface depictions 7-8 days out from the GFS (or even the Euro). Pay more attention to the 500mb level, pattern flows, and the source regions for the air coming down south (or not coming as it were). That being said, I find it remarkable to see this kind of agreement between the GFS and Euro at 216 hours out from today's 12z runs.

The GFS



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King Euro



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[Longhornmaniac8]

I'm wondering if somebody could elaborate a bit on the importance of the isobars? I've read multiple times of the importance of the 540 mb level, and was hoping for elaboration on specifically what that is, and why it's important to the presence/absence of winter weather in Texas.

Thanks!

Cheers,
Cameron

[Ntxw]

I'm wondering if somebody could elaborate a bit on the importance of the isobars? I've read multiple times of the importance of the 540 mb level, and was hoping for elaboration on specifically what that is, and why it's important to the presence/absence of winter weather in Texas.

Thanks!

Cheers,
Cameron

Are you asking about 540 thickness? Or the height anomalies at the 500mb level (decameters or dm)?

[wall_cloud]

I'm wondering if somebody could elaborate a bit on the importance of the isobars? I've read multiple times of the importance of the 540 mb level, and was hoping for elaboration on specifically what that is, and why it's important to the presence/absence of winter weather in Texas.

Thanks!

Cheers,
Cameron

I think you are a bit confused. Isobars are lines of constant pressure and are typically only used on surface charts. When someone plots a 500mb chart, all data plotted is at the same pressure so they tend to draw isohypses (lines of constant geopotential height). This shows shows the locations of ridges/trofs.

You mention the "540 mb level" and its importance. I have no doubt you are referring to the 540 decameter thickness line. This is the thickness in the layer between 500 mb and 1000 mb. It represents and average temperature throughout the that layer. People like to use it to forecast snow chances since the 540 line has tended to favor that magic changeover line. I personally don't find it all that important other than if you are just going to take a quick glance at the model. I recommend using point soundings to forecast precip type.

[Ntxw]

Is FW looking at the same models? To me, wouldn't it appear to be the opposite? Unless they are talking about the system prior to the expected 'big' storm. The ECMWF is the one predicting more winter weather next Monday/Tuesday, not GFS.

DIFFERENCES ON SYSTEMS REALLY GET REALIZED DAY 7/BEYOND AS THE GFS
ADVERTISES A STRONG SYSTEM ARRIVING SUN/MON IN THE SRN STREAM/
CONVERGENT UPPER FLOW OVER TX...WHILE THE ECMWF IS WEAKER/SLOWER/
AND FURTHER SOUTH WITH THIS FEATURE WITH BULK OF ANY PRECIPITATION
POTENTIAL REMAINING WELL TO THE SOUTH OF OUR AREA. AS STATED...WE`RE
ON BOARD WITH THE ECMWF FOR THE TIME BEING AND WITH IT`S BETTER
TRACK RECORD BEYOND DAY 5 IN MOST CASES.