Texas Winter 2011-2012...

[weatherdude1108]

Euro has temps 15-30 deg above normal across the Northern Plains and western/central Canada next week. Hard to get snow very far south with those temps. Temps across the central Rockies are forecast to be 5-20 deg below normal next week. Possible for some snow in the TX Panhandle/northern OK.

Ok, thanks guys, I just wondered why the models or at least the gfs, keeps trying to show something in our area when there is no source for really cold air. The rain part I could accept more easily.

I don't believe you necessarily need below normal temps in Canada to get cold enough air for snow deep into Texas this time of year. The high pressure seems to originate over Montana, slide south and build as it anchors itself over Colorado next weekend...both the Euro and GFS are showing this. The 12Z GFS now shows quite a winter storm over Texas on Christmas day. I realize it's over a week out but the GFS operational and Euro nailed this last system sitting over the southwest now from almost 10 days out, while the ensembles showed a very different scenario. (GFS operational has had a pretty good track record of late)

This scenario seems plausible considering the very low sun angle/long nights this time of year, snow cover building across the plains, and the orientation of the trough forecast across the southwest late next week...some 500 mb heights are forecast to be over 3 standard deviations below normal!!! The pieces are on the playing field, now lets see if they can all come together.

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.

I noticed that exact same thing on the GFS this morning around Christmas. It contradicted what I have seen with the most recent extended forecasts. Maybe we will have a white Christmas.

[gpsnowman]

I know it is 10 days out but when certain models agree this far out it is a good thing, right? I looked at the Weatherstreet models(to the best of my limited ability) and it looked like some cold and precip around that time frame.

[Ntxw]

I know it is 10 days out but when certain models agree this far out it is a good thing, right? I looked at the Weatherstreet models(to the best of my limited ability) and it looked like some cold and precip around that time frame.

They've done it a few times so far! And seems to have overestimated the cold air as the event drew near. I would not get excited about it unless the Euro shows it within the 3-5 day frame (it's been untouchable at that range). 6 more days till the official start of winter!

[weatherdude1108]

Why does a warming of the stratosphere often come before a major arctic outbreak? Does all of the cold arctic air build up behind the warm air then break through and dive south? Thanks.

From my understanding as the Stratosphere warms it expands and thus compresses the column of air beneath it, the troposphere. When air in the troposphere compresses, it cools/builds and begins to spread towards the middle latitudes - normally gravitating towards the central parts of the northern hemisphere's continents. To get a sustained arctic outbreak in the US, you need blocking to form over Greenland/Northern Atlantic to prevent the cold air from escaping out across the Atlantic.

A few things I think are still in question: 1) is the stratospheric warming going to materialize - its only forecasted by some computer models 2) if it does, where does the arctic air end up - Does it stay on the other side of the pole in Asia or Does it migrate over to North America? 3) if it makes it over to North America, does it funnel straight down into the plains or get pushed towards the east or west coast? These are all questions that appear way too early to answer

That is interesting! This reminds me of one of the "Weather Underground" blogs I read (can't remember who wrote it) recently about tropospheric warming. It was something like when you get warming of the troposphere, you get cooling of the stratosphere, and vice versa. My Atmospheric Science professor never went over that. He did mention an air parcel at a certain temperature and pressure cools as it rises through the troposphere, but when the parcel hits the stratosphere, it warms. He illustrated it with a line decreasing of decreasing temp, then increasing temp upon hitting the tropopause. It's been a while, so I may be wrong. Anyway, so tropospheric warming near the poles is a good indicator of an influx of cold air at lower latitudes? You probably explained already, but I feel like a curious school kid.

[orangeblood]

Why does a warming of the stratosphere often come before a major arctic outbreak? Does all of the cold arctic air build up behind the warm air then break through and dive south? Thanks.

From my understanding as the Stratosphere warms it expands and thus compresses the column of air beneath it, the troposphere. When air in the troposphere compresses, it cools/builds and begins to spread towards the middle latitudes - normally gravitating towards the central parts of the northern hemisphere's continents. To get a sustained arctic outbreak in the US, you need blocking to form over Greenland/Northern Atlantic to prevent the cold air from escaping out across the Atlantic.

A few things I think are still in question: 1) is the stratospheric warming going to materialize - its only forecasted by some computer models 2) if it does, where does the arctic air end up - Does it stay on the other side of the pole in Asia or Does it migrate over to North America? 3) if it makes it over to North America, does it funnel straight down into the plains or get pushed towards the east or west coast? These are all questions that appear way too early to answer

That is interesting! This reminds me of one of the "Weather Underground" blogs I read (can't remember who wrote it) recently about tropospheric warming. It was something like when you get warming of the troposphere, you get cooling of the stratosphere, and vice versa. My Atmospheric Science professor never went over that. He did mention an air parcel at a certain temperature and pressure cools as it rises through the troposphere, but when the parcel hits the stratosphere, it warms. He illustrated it with a line decreasing of decreasing temp, then increasing temp upon hitting the tropopause. It's been a while, so I may be wrong. Anyway, so tropospheric warming near the poles is a good indicator of an influx of cold air at lower latitudes? You probably explained already, but I feel like a curious school kid.

Now Tropospheric warming is a different topic all together but to answer your question, I'd say yes it normally is a good indicator of cooler air, lower heights at lower latitudes. This is due to the fact that in that scenario, you'd probably have some sort of blocking over the arctic... forcing colder air south and the disruption/displacement of the polar vortex further south bringing the arctic air with it.

[weatherdude1108]

I know it is 10 days out but when certain models agree this far out it is a good thing, right? I looked at the Weatherstreet models(to the best of my limited ability) and it looked like some cold and precip around that time frame.

They've done it a few times so far! And seems to have overestimated the cold air as the event drew near. I would not get excited about it unless the Euro shows it within the 3-5 day frame (it's been untouchable at that range). 6 more days till the official start of winter!

Definitely curious what the Euro shows later! Where is the best place/site to see all of the models?

[orangeblood]

Anyone noticed the 12Z Navy run for today? Not sure how accurate this model is but it shows an interesting storm track for North Texas folks. It brings the upper low much further south than the other models, which I haven't completely ruled out yet. The jog northeasterly shown by most models, once the low gets to west Texas, looks somewhat suspicious to me considering the main westerly flow is across the northern great lakes.

The model is obviously an outlier but it's on the table none the less.

Here's a link for the Navy model.... http://www.meteo.psu.edu/~gadomski/NOGAPS_0z/nogapsloop.html

[Ntxw]

Anyone noticed the 12Z Navy run for today? Not sure how accurate this model is but it shows an interesting storm track for North Texas folks. It brings the upper low much further south than the other models, which I haven't completely ruled out yet. The jog northeasterly shown by most models, once the low gets to west Texas, looks somewhat suspicious to me considering the main westerly flow is across the northern great lakes.

The model is obviously an outlier but it's on the table none the less.

Here's a link for the Navy model.... http://www.meteo.psu.edu/~gadomski/NOGAPS_0z/nogapsloop.html

Difference with the Navy model is it misses the northern stream connection with a slower storm probably and continues the cutoff track southerly. It also doesn't develop another strong SW storm to kick it out. It is an outlier and I wouldn't trust it, for now. But hey plenty of time for the others to change, will be hard to time the low until it starts moving which will be important.

[weatherdude1108]

Christmas weekend is still a little far out for this discussion as far as any potential wintry mix in Central Texas. But the rain is ALWAYS welcome these days.

000
FXUS64 KEWX 162103
AFDEWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
303 PM CST FRI DEC 16 2011

.DISCUSSION...
OVERCAST SKIES PREVAILED THIS AFTERNOON AS GULF MOISTURE CONTINUES
TO OVERRIDE THE COLD AIRMASS AT THE SFC. THIS OVERRUNNING MOISTURE
PATTERN WILL PERSIST THROUGH THE WEEKEND. WEAK PERTURBATIONS IN
THE SOUTHWEST FLOW ALOFT WILL PRODUCE PATCHY LIGHT RAIN TONIGHT
THRU SUNDAY. CAA AND OVERCAST SKIES WILL KEEP TEMPERATURES WELL
BELOW SEASONAL NORMALS.

AN UPPER LEVEL LOW PRESSURE SYSTEM CURRENTLY LOCATED OVER NORTHERN
BAJA CALIFORNIA WILL REMAIN STATIONARY THRU SUNDAY...PUMPING ABUNDANT
PACIFIC MOISTURE ACROSS SOUTH CENTRAL TEXAS. THIS UPPER LEVEL SYSTEM
WILL BEGIN MOVING TOWARDS TEXAS SUNDAY NIGHT. INCREASING WAA WILL
OCCUR ACROSS SOUTH CENTRAL TEXAS SUNDAY NIGHT INTO MONDAY IN ADVANCE
OF THE UPPER LEVEL LOW. THIS WILL ALLOW A WARM FRONT TO DEVELOP
OVER DEEP SOUTH TEXAS AND MOVE NORTHWARD ACROSS OUR CWFA ON MONDAY.
WIDESPREAD FOG DEVELOPMENT IS POSSIBLE SUNDAY NIGHT ALONG WITH
INCREASING CHANCES FOR SHOWERS...ALONG AND NORTH OF THE WARM
FRONT. THE SOUTHERN HALF OF OUR CWFA MAY ALSO SEE TEMPS SLOWLY
RISE SUNDAY NIGHT IN ASSOCIATION WITH THE NORTHWARD PROGRESSION
OF THE WARM FRONT.

THE CHANCE FOR THUNDERSTORMS RETURNS TO THE FORECAST FOR MONDAY.
AN UPPER LEVEL LOW WILL KICK OUT ACROSS SOUTHEAST NEW MEXICO AND
NORTHWEST TEXAS ON MONDAY WITH THE ASSOCIATED COLD FRONT MOVING
ACROSS SOUTH CENTRAL TEXAS MONDAY AFTERNOON. CONVERGENCE ALONG
THE FRONTAL BOUNDARY...DAYTIME HEATING AND GOOD SYNOPTIC SCALE
ASCENT WILL RESULT IN THE POTENTIAL FOR ISOLATED STRONG
THUNDERSTORMS MONDAY AFTERNOON AND EVENING. MONDAY WITH BE THE
WARMEST DAY OF THE UPCOMING WEEK WITH HIGHS IN THE 60S AND 70S.

ANOTHER COLD AND DRY AIRMASS WILL OVERSPREAD SOUTH CENTRAL TEXAS
MONDAY NIGHT IN THE WAKE OF THE FROPA. THIS AIRMASS WILL REMAIN
ENTRENCHED ACROSS THE CWFA FOR MOST OF NEXT WEEK. THE COLDEST
NIGHT WILL TUESDAY NIGHT WITH LOWS IN THE MID 30S ACROSS THE
HILL COUNTRY AND EDWARDS PLATEAU. CLOUDS WILL BE ON THE INCREASE
WEDNESDAY AS ANOTHER UPPER LEVEL LOW PRESSURE SYSTEM TRAVERSES
NORTHWEST MEXICO...MOVING ACROSS TEXAS ON THURSDAY. THE ASSOCIATED
COLD FRONT WILL PUSH SOUTHWARD ACROSS OUR CWFA ON FRIDAY IN THE
WAKE OF THE UPPER LEVEL TROF. THIS SYSTEM WILL BRING A CHANCE OF
SHOWERS TO OUR CWFA THURSDAY AND THURSDAY NIGHT.

&&

_________________
The above post and any post by Ntxw 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.

[aggiecutter]

Afternoon AFD from Shreveport:

"LOOKING AHEAD TO CHRISTMAS...USUALLY CHANCES FOR A WHITE CHRISTMAS
ARE LESS THAN 5 PERCENT IN ANY GIVEN YEAR BASED ON HISTORICAL
DATA. THE PAST FEW RUNS OF THE GFS AND TO SOME DEGREE THE ECMWF
HAVE BEEN BRINGING A CLOSED LOW ACROSS THE AREA AROUND CHRISTMAS
ON THE HEELS OF A FAIRLY STRONG ARCTIC HIGH BUILDING IN. SHOULD
THIS SCENARIO CONTINUE TO PLAY OUT...SOME FOLKS WOULD HAVE AT
LEAST A CHANCE OF SEEING SNOW ON CHRISTMAS...WHICH AT LEAST IN
SHREVEPORT HAS ONLY OCCURRED THREE TIMES SINCE 1874. TRACE SNOW WAS
REPORTED ON CHRISTMAS DAY IN 1876...1929 AND 1963."

[Turtle]

18z GFS appears a lot warmer around Christmas. It's strange that when 00z/12z is good, 18z isn't and vice versa. Hopefully the 00z will be colder.

[Ntxw]

18z GFS appears a lot warmer around Christmas. It's strange that when 00z/12z is good, 18z isn't and vice versa. Hopefully the 00z will be colder.

I would not buy into any solution beyond 5 days. There has been wild swings run to run by ALL of the models, even the historically favored European which has been erratic thus far from long range as well. The active subtropical jet and numerous pacific storms is just simply a headache to track and time. There might be a small piece of energy that blows up into a megastorm or vice versa (just example) so who knows really .

So current track by models for the Monday storm is from NM through west Texas into Oklahoma with heavy snow and winds from the Panhandles and far NW Oklahoma. Heavy rain along the I-35/I-45 corridors. Storm in question is now sitting in SoCal/Baja and will remain there for the weekend before it ejects.



P.S. Sorry about not saving the image, I haven't figured out how to get animated gif's to upload correctly and work with windows7

[weatherdude1108]

I have been reading this guy Bob Rose's weather blogs for several years. He has a weather blog for LCRA. He apparently has been getting questions on the rains Central Texas has had during November and December.  At the same time, the Pacific NW has had their driest December in years, unheard of in a La Nina. He also mentions the forecast for Christmas has changed just since yesterday.

http://www.lcra.org/water/conditions/we ... olumn.html



The above post and any post by Ntxw 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.

[Rgv20]

Tonight's 0zCMC brings a pretty potent front during the Holiday weekend....It has the 0C 850mb line crossing the whole state by Saturday morning.

[Turtle]

^Sounds great! Is there any precip accompanied with it? I would guess no by the map (green), but not sure if I read it right.

[Portastorm]

^Sounds great! Is there any precip accompanied with it? I would guess no by the map (green), but not sure if I read it right.

Actually, I think you were looking at the panel on the lower left which is the 700mb level. In a four-panel series like this and if you're curious about precip, focus on the panel on the lower right. And yes, you are right ... no precip per the CMC.

Unfortunately, I don't see anything "wintry" for most of Texas between now and Christmas after looking at the 0z GFS, Euro, and CMC. Then again as I have said previously as well as others ... the medium-range models have really struggled this season beyond five days so take it with a grain of proverbial salt.

[Portastorm]

I have been reading this guy Bob Rose's weather blogs for several years. He has a weather blog for LCRA. He apparently has been getting questions on the rains Central Texas has had during November and December.  At the same time, the Pacific NW has had their driest December in years, unheard of in a La Nina. He also mentions the forecast for Christmas has changed just since yesterday.

http://www.lcra.org/water/conditions/we ... olumn.html



The above post and any post by Ntxw 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.

Thanks for posting ... Bob is a friend of mine and a very good forecaster. He did a nice job on this writeup. His blog usually has some great information and he writes in an educational style.

[Rgv20]

Northern Panhandle is bracing for a significant winter storm starting Monday afternoon and ending on Tuesday. 12zECMWF has 12''+ of snow for the Dalhart and Boise City area!

Winter Storm Watch

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE AMARILLO TX
1250 PM CST SAT DEC 17 2011

...MODERATE TO HEAVY SNOW AND STRONG NORTH WINDS TO IMPACT THE
TEXAS AND OKLAHOMA PANHANDLES MONDAY INTO TUESDAY MORNING...

.A POTENT LOW PRESSURE SYSTEM CURRENTLY OFF THE SOUTHERN
CALIFORNIA COAST WILL EVENTUALLY TRACK EASTWARD INTO FAR SOUTHERN
NEW MEXICO BY MONDAY MORNING...AND THEN LIFT NORTHEAST ACROSS THE
EXTREME SOUTHERN TEXAS PANHANDLE INTO WESTERN OKLAHOMA BY TUESDAY
MORNING. THIS INTENSE LOW PRESSURE SYSTEM WILL TEAM WITH A STRONG
COLD FRONT THAT WILL PUSH SOUTH THROUGH THE PANHANDLES ON MONDAY
TO BRING MODERATE TO HEAVY SNOW TO THE OKLAHOMA PANHANDLE AND ALL
BUT THE FAR SOUTHEAST TEXAS PANHANDLE. IN ADDITION...STRONG NORTH
WINDS BEHIND THE COLD FRONT WILL LEAD TO BLOWING AND DRIFTING
SNOW...AND POOR VISIBILITIES.

OKZ001>003-TXZ001>014-016>018-180300-
/O.CON.KAMA.WS.A.0004.111219T1200Z-111220T1800Z/
CIMARRON-TEXAS-BEAVER-DALLAM-SHERMAN-HANSFORD-OCHILTREE-LIPSCOMB-
HARTLEY-MOORE-HUTCHINSON-ROBERTS-HEMPHILL-OLDHAM-POTTER-CARSON-
GRAY-DEAF SMITH-RANDALL-ARMSTRONG-
INCLUDING THE CITIES OF...BOISE CITY...KEYES...GUYMON...BEAVER...
FORGAN...DALHART...STRATFORD...SPEARMAN...GRUVER...PERRYTON...
BOOKER...HIGGINS...FOLLETT...HARTLEY...CHANNING...DUMAS...
BORGER...MIAMI...CANADIAN...VEGA...AMARILLO...PANHANDLE...
WHITE DEER...PAMPA...HEREFORD...CANYON...CLAUDE
1250 PM CST SAT DEC 17 2011

...WINTER STORM WATCH REMAINS IN EFFECT FROM MONDAY MORNING
THROUGH TUESDAY MORNING...

A WINTER STORM WATCH REMAINS IN EFFECT FROM MONDAY MORNING
THROUGH TUESDAY MORNING.

* EVENT...MODERATE TO HEAVY SNOW AND STRONG NORTH WINDS WILL
IMPACT THE OKLAHOMA PANHANDLE AND ALL BUT THE FAR SOUTHEAST
TEXAS PANHANDLE MONDAY INTO TUESDAY MORNING. STORM TOTAL
SNOWFALL ACCUMULATIONS OF 6 TO 12 INCHES ARE POSSIBLE ALONG
AND NORTHWEST OF A LINE FROM CANADIAN TO GLENRIO TEXAS...WITH
THE HIGHEST AMOUNTS EXPECTED ACROSS THE OKLAHOMA PANHANDLE AND
NORTHERN TEXAS PANHANDLE. FOR THE REMAINDER OF THE WATCH AREA
SOUTHEAST OF THIS LINE...INCLUDING AMARILLO...3 TO 6 INCHES OF
SNOW ARE EXPECTED. NORTH WINDS WILL INCREASE TO 20 TO 35 MPH
WITH GUSTS UP TO 45 MPH BEHIND THE COLD FRONT ON MONDAY...
PRODUCING BLOWING AND DRIFTING SNOW AND POOR VISIBILITIES.

* TIMING...RAIN WILL TRANSITION TO SNOW FROM NORTHWEST TO
SOUTHEAST ON MONDAY...WITH ALL SNOW EXPECTED BY EARLY MONDAY
EVENING. THE SNOW WILL CONTINUE MONDAY NIGHT...BEFORE ENDING
FROM SOUTHWEST TO NORTHEAST TUESDAY MORNING.

* IMPACTS...ROADS WILL BECOME ICY AND SNOW PACKED...LEADING TO
HAZARDOUS TRAVEL CONDITIONS. BLOWING SNOW PRODUCED BY THE
STRONG NORTH WINDS WILL LEAD TO POOR VISIBILITIES...INCLUDING
POSSIBLE WHITEOUT CONDITIONS AT TIMES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT
SNOW...SLEET...OR ICE ACCUMULATIONS THAT MAY IMPACT TRAVEL.
CONTINUE TO MONITOR THE LATEST FORECASTS.

&&

$$

JACKSON

[wxman57]

I'm not seeing much chance of any frozen precip south of Amarillo early next week. Generally north of Amarillo across the OK Panhandle into eastern Kansas for a narrow band of snow. Certainly no indication of any chance of snow down to Dallas or south to Austin next week or near Christmas. 12Z Euro has no precip at all across Texas after next Thursday through Christmas. Some light rain across southeast TX next Thursday, similar to the 12Z GFS.

[iorange55]

I'm not worried. I think something will come around in early January, or just after Christmas.

This is how last winter went. A few teases and then things picked up in January/February. Hopefully this winter will deliver.