Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 6

[aggiegeog]

0Z Canadian ensembles has no freezing temps for roughly the southeast 40 percent of Texas through 384 hours.

ECMWF has roughly 2.3 inches of rain for Austin on Friday and then dry and mild through Dec 26. Looking upstream at progged surface temps at places like Denver and Casper, the cold front possibly arriving Dec 27-28 in Texas is not nearly as cold as the Nov front.

The models may not be showing it yet as they are just starting to see what we have been expecting for a while, but I fully expect just about 100% of Texas will see freezing temps with that Arctic outbreak. Unlike November this front will have snow covered Plains states and late December sun angles to allow Arctic air to flow far south without much moderation though the El Nino cloud cover may prevent historic low temps high temps will likely be below freezing across large portions of Texas with this outbreak for multiple days.

[Nairobi]

I suspect the models have those parameters built in. Even places like Billings, Lethbridge, Whitehorse, and Calgary are progged by ECMWF to be warmer than November.

GFS has highs in the mid-upper 40s for Austin on Dec 29-30 before the high moves rapidly east and warming trend starts. Lowest temp progged by that model is 27. Dalhart's lowest temp in this colder air is 10.

GFS ensemble surface temperature anomaly is most severe the morning of Jan 2, with 18F below normal for the far northern Texas panhandle. That translates to a low in Dalhart of about 1F. For Austin, 11F below normal for a low of 30F.

[Quixotic1]

0Z Canadian ensembles has no freezing temps for roughly the southeast 40 percent of Texas through 384 hours.

ECMWF has roughly 2.3 inches of rain for Austin on Friday and then dry and mild through Dec 26. Looking upstream at progged surface temps at places like Denver and Casper, the cold front possibly arriving Dec 27-28 in Texas is not nearly as cold as the Nov front.

Ed?

[DFWWeather]

I suspect the models have those parameters built in. Even places like Billings, Lethbridge, Whitehorse, and Calgary are progged by ECMWF to be warmer than November.

GFS has highs in the mid-upper 40s for Austin on Dec 29-30 before the high moves rapidly east and warming trend starts. Lowest temp progged by that model is 27. Dalhart's lowest temp in this colder air is 10.

GFS ensemble surface temperature anomaly is most severe the morning of Jan 2, with 18F below normal for the far northern Texas panhandle. That translates to a low in Dalhart of about 1F. For Austin, 11F below normal for a low of 30F.

 

The ECWMF, both its operational and ensembles, are showing a pretty decent Arctic air outbreak the week following Christmas and have been for several runs (days really). This teleconnects well with stratospheric 10 mb warming episode over the pole earlier in the month and +PNA/Forecasted -AO/Forecasted -EPO/Forecasted -NAO. The GFS is also showing an Arctic air outbreak as are its ensembles, but the op does look much more progressive transient outbreak (which is a bias of this model) and doesn't seem to fit the teleconnective pattern nor the 500 mb pattern below. The below mean 10 day 500 mb mean pattern for both the ECMWF and GFS would support an Arctic air outbreak in a rather cold pattern with much below normal temps into much of the central CONUS. The 500 mb ridge over Alaska, as described below, supports more of a direct hit in the Plains east of the Rockies into Texas with these areas experiencing the coldest anomalies. How cold it will actually be is hard to determine and depends on source region of airmass/how big of a High/airmass modification if any. Historically, some of DFW coldest Arctic air outbreaks occur during this time of year, especially around the solstice. So I can easily see this dropping us to 20°F, if not colder, given the time of year. We got to 22°F in November. Whether this outbreak sends the LRGV to freezing is another matter and would require a full blown McFarland signature to the 500mb with quick delivery probably to do that. Given the El Niño signals and cloud cover possibilities could all spare them from freezing temps.

 

The Canadian 500mb mean below is also showing something similar, though it should have a stronger trough over the US like the other two models given the global pattern it has. I take that to mean it is going toward the other models and its operational hasn't caught on yet. Which is surprising as this model usually has cold bias.

 

[Nairobi]

ECMWF operational progging about 1.30 inches of rain for Austin ending Friday morning and then dry through Dec 27. Surface temperatures mild to cool with nothing close to freezing. Temperatures for the morning of Dec 27 include Austin (46), Amarillo (18), Denver (-11), Dallas (37), and Oklahoma City (25). Coldest temps for this 10-day period for spots farther north include Calgary (4), Lethbridge (0), Whitehorse (0), and Billings (2).

[Portastorm]

Latest QPF values from WPC's maps show 1.75-2.25 inches of rainfall for Austin ending Friday morning.

18z GFS showing some stout cold values for south central Texas close to New Years with high temps not getting above freezing in Austin on 12/31.

[Nairobi]

18Z GFS ensemble mean through 384 hours is very similar (if not warmer than the Canadian) in not showing any freezing temperatures for about half of Texas, not even in the mornings. It shows the coldest air heading for the midwest, with below 0 readings confined to the northeast half of North Dakota, most of Minnesota, and about half of Wisconsin. It also holds the -15 temps to near and just west and northwest of Hudson Bay.

18Z CFS also has the most significant negative temp anomalies heading to the midwest and northeast.

0Z GFS parallel has Austin getting down to 30 on Dec 28, the coldest point of this outbreak. By Jan 2, the cold is long gone. 0Z GFS operational is very similar with 0.38 inches of rain this Friday.

Meanwhile, Lake Travis is down exactly 5 feet since January 1.

[DFWWeather]

18Z GFS ensemble mean through 384 hours is very similar (if not warmer than the Canadian) in not showing any freezing temperatures for about half of Texas, not even in the mornings. It shows the coldest air heading for the midwest, with below 0 readings confined to the northeast half of North Dakota, most of Minnesota, and about half of Wisconsin. It also holds the -15 temps to near and just west and northwest of Hudson Bay.

18Z CFS also has the most significant negative temp anomalies heading to the midwest and northeast.

0Z GFS parallel has Austin getting down to 30 on Dec 28, the coldest point of this outbreak. By Jan 2, the cold is long gone. 0Z GFS operational is very similar with 0.38 inches of rain this Friday.

Meanwhile, Lake Travis is down exactly 5 feet since January 1.

 

The bottom line is that the pattern favors Arctic air to move south (whether you want to admit it or not) during the period after Christmas into the first week of January. Even the FWD NWS is talking about it in this morning's AFD. It is much too early to pinpoint just how cold it will get, but the 0z ECMWF Control does show a second Arctic airmass the weekend of New Year's moving into the State on or about Jan 2 with significant cold air damming along the eastern flank of the Rockies draining straight down into the state. So every model run will likely change in that time frame from run to run until they get a handle on the pattern change, but the general idea is there that Arctic air will move south in some fashion. If I remember correctly, the models were not catching the depth of the Arctic air in November correctly either 10 days before it happened. Taking the verbatim numerical output of models more than 10 days out is not a good forecasting technique.

[Srain]

Another 8 inches of fresh powder at Ski Taos yesterday bringing the 5 day total to an additional 28 inches of snow. Life is good for the southern slopes of the Sangre de Cristo Mountains of New Mexico. The pattern continues to favor Southern tracking storms with additional moisture from the Eastern Pacific. Glad I planned a mid January trip back to the area a couple of months ago. Should be a fun week of R & R in one of the best kept secrets of the Southern Rockies.

 

 

 

 

 

 

 

[aggiegeog]

Another 8 inches of fresh powder at Ski Taos yesterday bringing the 5 day total to an additional 28 inches of snow. Life is good for the southern slopes of the Sangre de Cristo Mountains of New Mexico. The pattern continues to favor Southern tracking storms with additional moisture from the Eastern Pacific. Glad I planned a mid January trip to the area a couple of months ago. Should be a fun week of R & R in one of the best kept secrets of the Southern Rockies.

Looks great, wish I could get up there. They should have a snowy winter with the continued El Nino southwestern storms.

[Quixotic1]

Nice shots Steve. Enjoy it. I remember feeling the same way as a kid in the early 70s about a little place called Aspen.

[Srain]

Looks great, wish I could get up there. They should have a snowy winter with the continued El Nino southwestern storms.

Most ski areas of New Mexico are doing just fine this year even down to Ruidoso (Ski Apache) and Cloudcroft. The pattern does continue to favor an active storm track. And LOL as the East Coast folks melting down and even cancelling Winter.

[Srain]

Morning briefing from Jeff regarding the current weather threat and the extended and even a look back at 10 years ago when the Texas Gulf Coast recorded a record Christmas Eve snow storm:

 

Strong storm system will move across TX Friday with a threat for heavy rainfall.

 

Surface warm front has moved inland overnight and stalled this morning along a line from roughly Bay City to Angleton to High Island. Scattered showers and thunderstorms have been moving across the area this morning along either side of this boundary with the most concentrated activity at the moment along the Matagorda and Brazoria County coasts. High resolution model guidance is in decent agreement with the warm front remaining nearly stationary today just inland of the beaches which is what I had suspected the last few days instead of the front pushing well inland which had been suggested by the global guidance earlier in the week. This will keep most of the area under cloudy, foggy, and drizzly conditions with periods of light rain and scattered showers all day. Best rainfall concentration will be from I-10 southward near the boundary.

 

Tonight-Friday morning:

Powerful storm system over S CA this morning will rapidly approach TX from the WSW. Surface low pressure will be forced over SW TX between Del Rio and Laredo and track ENE across SC and SE TX Friday morning. Impressive lift comes to bear on the region between midnight and noon on Friday and expect a significant increase in thunderstorm activity starting after midnight and continuing through mid-morning Friday. TX TECH 3km model shows some fairly impressive banding of rainfall for a 6-8 hour period Friday morning over the central and northern counties of the area.

 

With PWS forecasted to reach 1.40-1.60 inches Friday morning (very healthy moisture for mid December) combined with the strong sustain lift and upper level divergence aloft all points to thunderstorms with heavy rainfall. Cell motions will be quick toward the ENE and NE, but concern is there for repeat cell training leading to quick rainfall accumulations. Think the warm front will be the “big” focus for this main axis of heavy rainfall and it should push inland to near US 59 early Friday morning. Widespread rainfall amounts of 1-2 inches is likely with isolated totals of 3-4 inches especially near and just north of the warm front position. Area has been dry of late and expect most areas will be able to handle these rainfall amounts. However there could certainly be ponding and street flooding in the urban areas on Friday morning.

 

System moves east Friday afternoon with showers and thunderstorms rapidly ending. Cold front sweeps across the region ushering in colder temperatures for the weekend. Another upper level system quickly approaches on Sunday, but moisture is forecast to be limited and at the moment only an increase in cloud cover.

 

Extended:

Weather pattern shifts back toward a slower storm track and more zonal flow next week with the string of southern track storm systems ending. This should result in overall clearing skies and mild weather for the Christmas holiday. This looks short lived however as there continues to be suggestions in the long range guidance of a more significant pattern change to allow arctic air to enter into the US after Christmas and possibly move toward TX the weekend after Christmas. Models have been really struggling with this pattern change and the amount of cold air which may move southward in this time period.

 

Historical:

Next week marks 10 years since one of the most incredible weather events to ever be experienced on the Texas coast. Dec 24/25, 2004 marked one of the greatest snowfalls ever recorded along the coast. Totals ranged from over a foot at Victoria and Brazoria to ½ a foot at Wharton and Bay City. Snow fell and accumulated at Brownsville for the first time since 1895…a 109 year old record! It was the first and only “white Christmas” ever recorded along the TX coast and statically speaking has almost a 0% chance of happening again. While many weather events are considered “once in a lifetime” this event both on storm totals and the date on which it occurred both fit that phrase. For more information, snow totals, and pictures see the attached report.  

 

[Srain]

Nice shots Steve. Enjoy it. I remember feeling the same way as a kid in the early 70s about a little place called Aspen.

Thanks. I enjoyed Colorado back in the 70's as well, but since the 90's when the pattern is just right I found New Mexico to be a much better and less crowded area to make my sojourns to the Rockies. It is also less expensive and filled with a lot of good folks that are generally appreciative of us Texans choosing to spend our dollars in their much friendlier environs.   

[Portastorm]

The bottom line is that the pattern favors Arctic air to move south (whether you want to admit it or not) during the period after Christmas into the first week of January. Even the FWD NWS is talking about it in this morning's AFD. It is much too early to pinpoint just how cold it will get, but the 0z ECMWF Control does show a second Arctic airmass the weekend of New Year's moving into the State on or about Jan 2 with significant cold air damming along the eastern flank of the Rockies draining straight down into the state. So every model run will likely change in that time frame from run to run until they get a handle on the pattern change, but the general idea is there that Arctic air will move south in some fashion. If I remember correctly, the models were not catching the depth of the Arctic air in November correctly either 10 days before it happened. Taking the verbatim numerical output of models more than 10 days out is not a good forecasting technique.

 

Yep. Agreed. And following suite, the 6z parallel GFS shows an Arctic Outbreak into the Southern Plains on December 27th with a 1058 mb high coming down into Montana. It is the classic approach to Arctic air into Texas.

[Nairobi]

06Z GFS ensemble mean through 384 hours does not show any freezing temperatures for about half of Texas, not even in the mornings. It shows the coldest air heading for the midwest, with below 0 readings confined to North Dakota, most of Minnesota, and some of Wisconsin. It also holds the -15 temps to near and just west and northwest of Hudson Bay.

12Z Canadian operational through 240 hours shows a light freeze for Austin and San Antonio areas on Dec 28. But the 0Z Canadian ensemble mean through 384 hours is similar to the 06Z GFS ensemble mean.

06Z CFS has the most significant negative temp anomalies heading to the midwest and northeast.

12Z GFS parallel has Austin getting down to 30 on Dec 28 and 29 and after a strong New Year's Day cold front, perhaps 25 on Jan 2. But the brunt of the cold heads to the midwest, with Chicago at about -16. 12Z GFS operational shows 2 light freezes for Austin through Jan 3 with 0.30 inches of rain this Friday.

ECMWF operational shows no freezes for Austin through the morning of Dec 27 but 14 degrees in Dalhart that morning. 0Z ECMWF ensemble mean at 240 hours shows normal 500 mb heights for southern 2/3 of Texas with westerly flow. However, the northern 2/3 of Texas has below normal 850 mb temps.

[Srain]

06Z GFS ensemble mean through 384 hours does not show any freezing temperatures for about half of Texas, not even in the mornings. It shows the coldest air heading for the midwest, with below 0 readings confined to North Dakota, most of Minnesota, and some of Wisconsin. It also holds the -15 temps to near and just west and northwest of Hudson Bay.

12Z Canadian operational through 240 hours shows a light freeze for Austin and San Antonio areas on Dec 28. But the 0Z Canadian ensemble mean through 384 hours is similar to the 06Z GFS ensemble mean.

06Z CFS has the most significant negative temp anomalies heading to the midwest and northeast.

0Z GFS parallel has Austin getting down to 30 on Dec 28, the coldest point of this outbreak. By Jan 2, the cold is long gone. 12Z GFS operational shows 2 light freezes for Austin through Jan 3 with 0.30 inches of rain this Friday.

ECMW operational shows no freezes for Austin through the morning of Dec 27.

Nice summation of what most here already know. Care to offer any actual thoughts or analysis as to why the guidance is correct or not? Pro Tip...The Weather Prediction Center offers some reasonable analysis of the volatility next week across the Lower 48...

 

EXTENDED FORECAST DISCUSSION

NWS WEATHER PREDICTION CENTER COLLEGE PARK MD

1059 AM EST THU DEC 18 2014

VALID 12Z SUN DEC 21 2014 - 12Z THU DEC 25 2014

...INTENSE LOW PRESSURE TO IMPACT THE EASTERN 1/3RD OF THE NATION

ON CHRISTMAS EVE AND CHRISTMAS DAY...

...OVERVIEW...

ACTIVE SPLIT-FLOW PATTERN FOR THE WEST---WILL TRANSITION TO A MORE

AMPLIFIED PATTERN ACROSS THE LOWER 48 THIS MEDIUM RANGE

PERIOD---WITH A SHORTWAVE RIDGE IN THE WEST AND A

NEGATIVELY-TILTED TROUGH IN THE GREAT LAKES AND

MID-ATLANTIC/NORTHEAST REGION.

...UNCERTAINTY ASSESSMENT...

IN THE EAST...IT WILL ULTIMATELY COME DOWN TO SURFACE CYCLONE

DEPTH...BUT FROM A SENSIBLE WEATHER PERSPECTIVE---THE EMBEDDED

ENERGY NOTED IN THE DETERMINISTIC GUIDANCE AS A TRIPLE-POINT

LOW---SHOULD BE THE FOCUS FOR AN INTENSE REGION OF LOW-LEVEL

CONVERGENCE AND STRONG WINDS. THE FORECAST UNCERTAINTY IS HOW THE

FEATURE MIGRATES FROM THE PIEDMONT NORTH-NORTHWESTWARD THROUGH

TIME.

IN THE WEST...THE UNCERTAINTY IS WHETHER OR NOT THE ~150+ METER

HEIGHT FALLS MOVING SOUTHWARD FROM THE BC COAST INTO NORTHERN

CALIFORNIA...WILL CLOSE OFF INTO A CLOSED 500MB CIRCULATION IN THE

GREAT BASIN. AND HOW FAR SOUTH WILL COLD/DRY CANADIAN SPILL INTO

THE PACIFIC NORTHWEST---WEST OF THE CONTINENTAL DIVIDE.

IN THE CENTRAL PORTION OF THE COUNTRY...THE UNCERTAINTY LIES IN

THE OUTCOME OF  THE VERY DEEP CIRCULATION IN SOUTHEAST CANADA AND

TRAJECTORIES (SOUTHWESTWARD PUSH) OF LOW-LEVEL COLD

ADVECTION---ORIGINATING IN THE CANADIAN PRAIRIE PROVINCES

(PRIMARILY SASKATCHEWAN/MANITOBA) IN THE SYSTEM'S

POST-STRENGTHENING PHASE.

...MODEL PREFERENCES...

THE 18/00Z DETERMINISTIC GFS/ECMWF WERE REASONABLE PIECES OF

FORECAST GUIDANCE THROUGH DAY 7. THE ECMWF IS A FASTER SOLUTION IN

THE NORTHEAST...WITH THE TRIPLE POINT (OCCLUSION-COLD-WARM FRONT)

AND A DEEPER SOLUTION AT THE SURFACE IN THE GREAT BASIN. THE

18/00Z ECENS/GEFS MEANS ARE REASONABLE. ALOFT...BOTH CARRY A

CLOSED SUB-522DM 500MB LOW CENTER MIGRATION ACROSS SOUTHEAST

CANADA...BUT THEY LOOK UNDERDONE WITH THE PRIMARY SURFACE CYCLONE

DEPTH INVOF LAKE HURON EASTWARD TO CENTRAL QUEBEC (984MB)---25/00Z

AND 25/12Z TIME FRAME.

THE SURFACE/500MB GRAPHICS USED THE AFOREMENTIONED DETERMINISTIC

GUIDANCE AT A 30/30 CLIP TO F144 (24/12Z) WITH A 20/20 RATIO FOR

EACH CORRESPONDING MEAN TO ACCOUNT FOR SPREAD. I TAPER AWAY FROM

THE 'WEAKER' DETERMINISTIC GFS---PRIMARILY TO HANDLE THE

MID/UPPER-LEVEL WAVE MIGRATION IN THE WEST AND GREAT BASIN.

FINALLY...MORE OF A 60/40 ECENS/GEFS BLEND AT F168 (25/12Z). GIVEN

THE DYNAMIC PATTERN ACROSS THE LOWER 48...HAVE ABOVE AVERAGE

CONFIDENCE IN THE 18/00Z CYCLE GUIDANCE AND BLEND CONFIGURATION

ALOFT. BELIEVE THE SURFACE GRAPHIC FOR DAY 7 WILL REQUIRE SOME

ALTERATION AS THE DETAILS BECOMES BETTER DEFINED WITH RESPECT TO

THE INTENSITY OF THE LOW-LEVEL WIND FIELDS.

...SENSIBLE WEATHER HIGHLIGHTS...

CHRISTMAS EVE/DAY CYCLONE---24/12Z TO 25/12Z TIME FRAME---WILL

HAVE REACHED FULL MATURITY---USHERING IN COLD ADVECTION ACROSS THE

NORTHEAST QUARTER OF THE NATION.

LOOKS TO BE A BROAD-SCALE AND RATHER INTENSE WIND/RAIN SCENARIO

EMBEDDED WITHIN THE WARM SECTOR...ALONG THE COLD FRONT AND INVOF

THE TRIPLE-POINT. IN THE SOUTHEAST...THE FRONTAL PASSAGE AND

WINDS/RAIN WILL BE MORE OF A CHRISTMAS EVE EVENT...WITH A DRY WEST

WIND ON CHRISTMAS DAY. AT A MINIMUM---SURFACE LOW AND ITS TROWAL

FEATURE SHOULD BE CONTINUING TO LIFT MOISTURE---IN THE FORM OF

SNOW---FROM THE CANADIAN MARITIMES---WESTWARD TO LAKE

HURON/SUPERIOR. EMBEDDED WITHIN THE COLD SECTOR...SCATTERED SNOW

SHOWERS---THE UPSLOPE FLOW MECHANISM GENERATING THE PRECIPITATION

IN THE APPALACHIANS/NEW ENGLAND AND SYNOPTIC-SCALE LAKE EFFECT FOR

THE GREAT LAKES. FOR THE NORTHERN/CENTRAL PLAINS AND MIDWEST...A

SHALLOW BUT STEEP MID-LEVEL LAPSE RATE ENVIRONMENT MAY PRODUCE

ISOLATED SNOW SHOWER ACTIVITY.

THE WPC TEMPERATURE FORECAST IS GOING TO TREND COOLER THAN

CONTINUITY IN THE PACIFIC NORTHWEST---TO ACCOUNT FOR A COOLER

CANADIAN AIRMASS WEST OF THE CONTINENTAL DIVIDE. THE QPF/POP

FORECAST LEANING FOR SOME ADDITIONAL AREAS OF PRECIPITATION IN THE

GREAT BASIN ALONG THE LEADING EDGE OF THE HEIGHT FALLS.

VOJTESAK

 

[Nairobi]

Nope. Will leave that to the more knowledgeable folks.

[Portastorm]

Nope. Will leave that to the more knowledgeable folks.

 

Interesting that your signature line says "just the facts."  Which "facts" would those be, the "warm" ones? You clearly have a warm bias and that's fine ... but if the models were overwhelmingly suggesting no Arctic or cold air in the Plains/Texas, why are so many nationally known pro mets calling for it happen?  What are you seeing that they're not? I'm curious.  Please educate me.

[DFWWeather]

Nope. Will leave that to the more knowledgeable folks.

 

Might I make a suggestion that you find a more positive way to interact with us "more knowledgeable folks" and let us express our ideas based on what we know of the weather, pattern recognition, and model biases. This is supposed to be an educational, thought provoking, sharing of ideas forum/discussion, but your posts are being read as inflammatory to our ideas based on verbatim model output without any insight or hypothesis as to why you might think that to be correct, other than the model says so. A lot of us on this board have very good ideas and insights and are very capable great forecasters. If you really think the pattern to be overwhelmingly warm in the period after Christmas into the first week of January, great and fine, but share why.

[Quixotic1]

The models are also overwhelmingly in agreement of a -AO,-EPO and -NAO in the last week of the month.  A cold signal, no matter the departures in Canada. 

 

Nairobi, I don't know how familiar you are with Texas Nino events, but it doesn't take much to get snow popping.  Strong H5 lows like the ones we've been having will step things down, temperature wise.  Despite the warm temps the last month, it was 38 and heavy rain IMBY last night.  It won't take much more to get it wintry.  2009-10 wasn't that cold but it was cold enough.  The February 11-12 event was right at 30 degrees.    

[Quixotic1]

Thanks. I enjoyed Colorado back in the 70's as well, but since the 90's when the pattern is just right I found New Mexico to be a much better and less crowded area to make my sojourns to the Rockies. It is also less expensive and filled with a lot of good folks that are generally appreciative of us Texans choosing to spend our dollars in their much friendlier environs.   

Ha.  Yet another victim of Texas bias.  We got it too.  Funny thing was, we were about 4 months removed from being Bostonians.  i'm going to try Taos one of these winters (+ENSO of course).  I recommend Tahoe City in California too.      

[Nairobi]

12Z GFS ensemble mean is virtually identical to the 06Z run. That is, through 384 hours, it does not show any freezing temperatures for about half of Texas, not even in the mornings. It shows the coldest air heading for the midwest, with below 0 readings confined to North Dakota, most of Minnesota, and some of Wisconsin. It also holds the -15 temps to near and just west and northwest of Hudson Bay.

12Z ECMWF operational shows significant above normal 850 mb temperature anomalies for most of Texas at 240 hours.

12Z Canadian ensemble mean at 384 hours shows morning freezing surface temps confined to the northwestern 40 percent of Texas.

[Srain]

Ha.  Yet another victim of Texas bias.  We got it too.  Funny thing was, we were about 4 months removed from being Bostonians.  i'm going to try Taos one of these winters (+ENSO of course).  I recommend Tahoe City in California too.

I am very familiar with the Tahoe area. Kirkwood was a favorite back in the late 90's and even Ski Shasta was a great find back in the day in Northern California. One of the all time favorite memorable trips was driving from Carlsbad to Roswell and on up to Ruidoso right after a massive blizzard that dropped over 100 inches in a week at Christmas time back in the mid to late 90's. These days I fly so this trip will be on Dreamliner into DEN and then a quick flight into SAF.

[Nairobi]

18Z GFS operational has no freezing temps for Austin through 384 hours and 0.24 inches of rain tomorrow. ECMWF operational likewise has no freezing temps through Dec 27.

18Z GFS parallel has mostly above normal to some normal 500 mb heights over Texas on Dec 28 with a flat westerly flow. But it progs a 1052 mb ridge over northern Yukon on that date with 35F below normal surface temps under that ridge. The main target of that ridge is east of Texas where central, snow-covered Mississippi on Jan 3 is progged to be -4F.

[Srain]

Heavy rain with thunder has been ongoing across Metro Houston the past several hours with some isolated flooding issues to the NE in the Piney Woods of East Texas into Louisiana.

The Global ensembles are still indicating a +PDO/-EPO/+PNA/-AO/-NOA regime develops as a very deep 5H low wraps up near the Great Lakes around Christmas and ushers in a significant pattern change as a strong blocking pattern develops and a cross polar flow brings very cold air south across the Canadian Prairies into the Plains just before the New Year. In fact the 2 meter temperatures for IAH plunge to the upper 20's for daytime highs with lows in the mid to upper teens to around 20F via the 00Z OP GFS in the longer range. If the 500mb charts are correct via the ensembles, a prolonged below freezing period could be possible as January 2015 begins.

[Nairobi]

0Z parallel GFS has no freezing temps for Austin through 6pm CST Jan 3. The largest anomalies go well east and northeast of Texas.

From this morning's Billings, MT forecast discussion for the weekend after Christmas:

Yesterday's models were hinting at a much colder push of arctic air for the weekend. The latest runs have backed off of this solution.

[aggiegeog]

0Z parallel GFS has no freezing temps for Austin through 6pm CST Jan 3. The largest anomalies go well east and northeast of Texas.

From this morning's Billings, MT forecast discussion for the weekend after Christmas:

Until we get much closer the 500mb pattern is what we need to watch develop. Sensible weather is too variable at this range.

[Nairobi]

06Z GFS operational is not nearly as cold as the previous run. Nothing severe or historic in its temp progs for Austin. Lowest temp is 25 during the cold snap and well above freezing every afternoon.

The progged 500 mb pattern varies slighy by model. But one thing they consistently have in common is fast zonal westerly flow over Texas with very little in below normal heights.

[aggiegeog]

06Z GFS operational is not nearly as cold as the previous run. Nothing severe or historic in its temp progs for Austin. Lowest temp is 25 during the cold snap and well above freezing every afternoon.

The progged 500 mb pattern varies slighy by model. But one thing they consistently have in common is fast zonal westerly flow over Texas with very little in below normal heights.

What do heights over Alaska look like? As has been said and seen last year we just need a big high to dislodge the cold, it will move south under it's own weight. The longevity of the cold will be determined by if the Alaska and North Atlantic highs can hold their position.