Texas Winter 2014-2015

[Ralph's Weather]

I am going to be paying close attention to the 850 temps as that will be the tell for what the precip types will be. I have seen these lows produce good snow when surface temps were progged to be way warm. I am going to review a storm from about this time in 2008 I think to see how it compares, I was in College Station at the time and we got a good 3 or so inches overnight.

That particular December bowling ball cold core upper low brought snow across Metro Houston as well. Some locations on the E side near Pasadena/Channelview/La Porte recorded nearly 6-8 inches of snow and it closed the Fred Hartman Bridge between La Porte and Baytown as well as the 610 E Loop and East Belt Bridges over the ship channel.

I remember it very very well. It happened twice that year. Both cold core lows and both were not predicted AT ALL. December 10th 2008 for one and the other was Feb 2009 i think.

It was in the low 40's as the cold core approached and temps fell with the snow

I love forecasting these and it seems like it has been a while since we have had a good one to watch.

[TeamPlayersBlue]

Not only that, it was almost 80 just the day before lol

[weatherdude1108]

The EWX is leaning more towards the "inferior" GFS (compared to the Euro) in this morning's forecast discussion. May get interesting late this weekend/next week (at this time ).

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
322 AM CST MON DEC 8 2014

.LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...
THE SHARP MID LEVEL RIDGE SHIFTS PROGRESSIVELY EAST TUESDAY NIGHT
WITH ANOTHER WEAK SHORTWAVE TROUGH HELPING TO DEEPEN MID AND UPPER
LEVEL MOISTURE QUICKLY OVER THE AREA TUESDAY NIGHT INTO WEDNESDAY.
MODEL CONSENSUS AGAIN ACCOUNTS FOR A WEAK OVERRUNNING OF EASTERLY
LOW LEVEL WINDS AND DEPICTS LOW CHANCE CATEGORY POPS WEDNESDAY
INTO THURSDAY. THIS LOOKS REASONABLE...WITH LOW QPF AMOUNTS
EXPECTED SIMILAR TO LAST WEEK. BY FRIDAY LOW LEVEL WINDS SHOULD
TURN SLIGHTLY MORE SOUTHERLY AND ONSHORE IN RESPONSE TO A
DEEPENING LOW LATITUDE STORM SYSTEM OVER THE SWRN US. WITH MOST
MODELS FAVORING A CLOSED LOW CIRCULATION OVER AN OPEN WAVE WHEN
REACHING TX...WILL DEFER TO MOST COLD SEASON UPPER LOW TENDENCIES
AND FAVOR A LOWER AND SLOWER SOLUTION. THUS THE GFS...WHICH HAS
SHOW DECENT RUN-TO-RUN CONSISTENCY OVER THE PAST DAY...COULD PAN
OUT AND CREATE HIGH RAIN CHANCES AND POSSIBLY A STRONG STORM
ENVIRONMENT. THIS FAR OUT...WILL ADOPT THE GFS TIMING OF BEST
RAIN CHANCES BUT NOT STRAY TOO FAR FROM MODEL CONSENSUS ON THE
OVERALL CHANCE OF RAIN AND QPF.

&&

[orangeblood]

As other posters have mentioned, Models are trending very stormy/cold for the next few weeks, just in time for the Holidays. Tonight's Euro weeklies should confirm same

[Texas Snowman]

It's funny, but this period of "relaxation" after the big November chill seems almost like a "January Thaw."

And while it doesn't always happen, it seems to me that winter often comes back with a vengeance after such periods of relaxation. Looking forward to seeing if that actually happens the last half of this month.

Also, Ntxw mentioned the other day about cloudy, cool weather developing as is typical in an El Nino year. After a weekend in a North Texas deer stand, I can assure you that there wasn't much that was mild/warm about this weekend, especially when you're sitting outside for several hours. No arctic fronts or sub-freezing weather, but still pretty damp and chilly weather over the past several days in my book.

[aggiecutter]

Just how cold was November for Texas. Cold, but nothing near record cold:

[Nairobi]

Off topic, but global temps were well above normal in November.

[TeamPlayersBlue]

Off topic, but global temps were well above normal in November.

Semi El nino year. No surprise there.

https://twitter.com/wsi_energy/status/5 ... 0226923521

This is a link of the canadian ensembles. That looks to be a good twitter follow as well.
SSW event last week?
https://twitter.com/wsi_energy/status/5 ... 2318889984

[Nairobi]

GFS says at precip cutoff time for 500, 850, and 925 meter temps:

Austin -18, 10, 17
Amarillo -20, 3, 8
Dallas -20, 9, 15
Lubbock -19, 2, 7

Which GFS? The operational or ensembles? If op, which run? Please clarify.

Edited the original post.

[Nairobi]

12/8 12Z operational GFS
At precip cutoff time, temps in Celcius for 500, 850, and 925 meter levels with total event precip:

Amarillo -20, 4, 10, 0.06
Austin -17, 11, 17, 0.68
Dallas -15, 6, 6, 2.08
Houston -14, 10, 15, 0.69
Lubbock -19, 4, 9, 0.24
San Angelo -19, 10, 17, 0.41
San Antonio -14, 11, 17, 0.56
Texarkana -14, 6, 9, 0.87
Waco -19, 10, 16, 1.56

A 39 hour traverse from far west Texas to the Louisiana border.

[TheProfessor]

Looking back at some of the snow storms here in Texas, it seems like this low could be similar to the one back in March 2010, which is the one that formed a very small connective band dumping 5-9 inches in Collin County. I'm not saying anything on that magnitude is going to happen, but these type of lows can bring surprises sometimes.

[TeamPlayersBlue]

I completely agree. Lots can happen.

[Tireman4]

The December 2004 storm? LOL

[orangeblood]

The second system transversing the southwest US towards the end of the 10 day period seems to have the most potential for winter weather across Texas....it will probably have more cold air to work with across the central and northern US.

[weatherdude1108]

000
FXUS64 KEWX 082155
AFDEWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
355 PM CST MON DEC 8 2014

.SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...
WITH YESTERDAYS SHORTWAVE WELL TO THE EAST AND RIDGING BEGINNING
TO TAKE PLACE OVER THE NEXT COUPLE DAYS...DRIER CONDITIONS LIKE
TODAY WILL LAST AT LEAST THROUGH TUESDAY. NOT MUCH CHANGE FROM THE
PREVIOUS FORECAST THINKING AS IT STANDS IN THE SHORT TERM.
INCLUDED PATCHY FOG MENTION CWA-WIDE FOR THE LATE EVENING AND
OVERNIGHT PERIODS THROUGH MID MORNING. OTHERWISE A PRETTY CALM
SHORT TERM FORECAST.

&&

.LONG TERM (WEDNESDAY THROUGH MONDAY)...
THE RETURN OF RETURN FLOW WILL BEGIN WEDNESDAY MORNING. WHICH WILL
BEGIN A MULTI DAY PROCESS OF MOISTENING THE ATMOSPHERE. A SERIES
OF WEAK SHORTWAVES...ONE ORIGINATING FROM THE SOUTHERN CALIFORNIA
COAST AND ANOTHER FROM NORTH DAKOTA...WILL INTERACT TO FORM A
QUAZI TROUGH AXIS OVER CENTRAL TEXAS LATE WEDNESDAY NIGHT AND
THURSDAY MORNING. THIS SHOULD COUPLE WITH THE MORE MOIST
ENVIRONMENT FOR SOME LIGHT SHOWER ACTIVITY PRETTY MUCH EACH DAY
THROUGH THE BEGINNING OF THE WEEKEND. THE WARMEST DAY LOOKS LIKE
SATURDAY WITH HIGHS REACHING THE MID 70S IN OUR SOUTHERN COUNTIES.
THE RIDGE AXIS WILL BE OVERTOP CENTRAL TEXAS AND AT ITS MOST
AMPLIFIED...JUST IN ADVANCE OF A MUCH MORE SIGNIFICANT UPPER LEVEL
SYSTEM PROGGED TO BEGIN IMPACTING THE STATE SUNDAY.

REGARDING THAT SYSTEM...CONSIDERING PREVIOUS RUNS WERE SO STARKLY
DIFFERENT FROM RUN TO RUN AND BETWEEN EACH SYNOPTIC MODEL...IT IS
QUITE SURPRISING HOW MUCH AGREEMENT EXISTS IN THE LONG RANGE
MODELS WITH THE 12Z RUNS. BOTH ARE SHOWING A STRONGLY AMPLIFIED
UPPER LEVEL LOW EVOLVING FROM THE MIDDLE CALIFORNIA COAST TO THE
SOUTHERN ROCKY MTNS. THIS LOW BECOMES CUT OFF AS IT ENTERS THE
STATE AND ALSO BECOMES SLIGHTLY NEGATIVELY TILTED. THIS RESULTS IN
WELL AGREED UPON PVA AND HEIGHT FALLS OVER WEST CENTRAL TEXAS AND
NORTHERN HILL COUNTRY BY LATE SUNDAY AFTERNOON. IN THE UPPER
LEVELS...MODERATE 250MB DIVERGENCE DEVELOPS AS IN BOTH
MODELS...MORE IMPRESSIVELY IN THE EURO...OVER EAST AND NORTHEAST
TEXAS SUNDAY EVENING.

LOWER IN THE ATMOSPHERE...A 40-45KT LLJ IS BEING SHOWN IN BOTH
MODELS TO DEVELOP BY 18Z SUNDAY...EFFICIENTLY ADVECTING LOW LEVEL
MOISTURE ACROSS MUCH OF THE EASTERN HALF OF THE STATE. AT THE
SFC...A MODERATELY UNSTABLE AIR MASS...AT LEAST FOR
DECEMBER...WILL BE IN PLACE WITH LI VALUES IN THE -2 TO -4 RANGE
ON FORECAST SOUNDINGS AND SFC BASED CAPES AT 800-1000 J/KG UP AND
DOWN THE I35 CORRIDOR UP TO JUST SOUTH OF DALLAS. PWAT VALUES ARE
OVER AN INCH AS WELL.

BASICALLY...CONFIDENCE HAS INCREASED QUITE A BIT FROM PREVIOUS
DAYS ON THIS SYSTEM WITH BOTH MODELS BEING IN SUCH GOOD AGREEMENT.
BASED OFF THE PARAMETERS ADVERTISED...A STRONG AND POTENTIALLY
SEVERE THUNDERSTORM SITUATION COULD DEVELOP SUNDAY AFTERNOON AND
EVENING...MAINLY FOR THE NORTHERN AND EASTERN HALF OF OUR CWA. DO
THINK HEAVY RAIN IS THE THREAT WITH THE MOST CONFIDENCE BUT THE
SYSTEM COULD CONTAIN DAMAGING WINDS AS WELL. WOULD LIKE TO SEE
BETTER LAPSE RATES IN THE SOUNDINGS FOR HAIL POTENTIAL BUT THAT
THREAT COULD EVOLVE WITH MORE RESOLUTION IN THE SHORT TERM MODELS.

[Portastorm]

Thanks for posting that weatherdude. This low will definitely be a weather-maker for Texas and could be a headline grabber.

Meanwhile, the steady drumbeat continues from pro mets about the pattern changing in late December. Here is an interesting post today from WSI's Michael Ventrice:

http://www.wsi.com/blog/energy/transition-back-to-a-cold-and-high-heating-demand-pattern-during-the-turn-of-the-new-year/

[CaptinCrunch]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
259 PM CST MON DEC 8 2014

.DISCUSSION...
LOW CLOUDS WEST AND NORTHWEST OF THE METROPLEX AND ALONG THE
RED RIVER WILL CONTINUE TO ERODE THIS AFTERNOON WITH CLEAR SKIES
EXPECTED BEFORE SUNSET. THIS WILL AGAIN LEAD TO A GOOD NIGHT FOR
STRONG RADIATIONAL COOLING WITH FOG FORMATION BEGINNING AFTER
MIDNIGHT. AREAS OF DENSE FOG ARE POSSIBLE IN THE PRE-DAWN HOURS
THROUGH THE EARLY MORNING COMMUTE. EXPECT THE FOG WILL BURN OFF IN
THE LATE MORNING HOURS. ONCE THE FOG BURNS OFF...THE REST OF
TUESDAY WILL BE SUNNY WITH HIGHS IN THE MID 60S.

WEDNESDAY AND THURSDAY...SEVERAL SHORT WAVES WILL BE AFFECTING
THE REGION DURING THE PERIOD WHILE MOISTURE OVER THE SOUTHERN
ROCKIES AND NORTHERN MEXICO SPREADS EASTWARD. THIS WILL RESULT A
RETURN OF CLOUDY SKIES AND A LOW CHANCE OF LIGHT SHOWERS OVER THE
WESTERN COUNTIES WEDNESDAY NIGHT AND THURSDAY. HIGHS WILL BE A
LITTLE COOLER DUE TO THE INCREASE IN CLOUD COVER.

FRIDAY AND SATURDAY...UPPER LEVEL RIDGING WILL BE MOVING ACROSS
THE REGION. THUS...A LITTLE MORE SUN...WARMER HIGHS AND AN
INCREASE IN SOUTH WINDS.

SUNDAY THROUGH MONDAY...CONFIDENCE IS BUILDING THAT A STRONG UPPER
CLOSED LOW WILL MOVE DIRECTLY ACROSS THE REGION WITH THE
POTENTIAL TO PRODUCE OUR FIRST GOOD RAIN EVENT OF DECEMBER. ALL
MODELS ARE NOW IN BETTER AGREEMENT WITH THE TRACK AND STRENGTH OF
THIS SYSTEM. THE ECMWF HAS A CORE THAT IS SLIGHTLY DEEPER AND SEVERAL
DEGREES COLDER THAN THE GFS DURING ITS PASSAGE THROUGH THE STATE.
AS IT COMES OUT OF THE SOUTHERN ROCKIES SUNDAY MORNING...STRONG
CYCLOGENESIS WILL TAKE PLACE IN WEST TEXAS WITH THE SURFACE LOW
MOVING ALONG I-20 AND INTO NORTHERN LOUISIANA BY MONDAY EVENING. A
COLD FRONT WILL MOVE ACROSS THE FORECAST AREA SUNDAY AFTERNOON AND
EVENING...AND THIS WILL BE THE BEST TIME PERIOD FOR STRONG
CONVECTION. RIGHT NOW...DYNAMICS AND INSTABILITY ON SUNDAY
AFTERNOON/EVENING DO JUSTIFY STRONG THUNDERSTORMS. IF THE SYSTEM
WAS NOT VERTICALLY STACK MOVING ACROSS THE CWA...THEN DIRECTIONAL
SHEAR WOULD BE MORE FAVORABLE FOR SEVERE STORMS. THERE COULD BE
SOME WRAP-AROUND PRECIPITATION LATE SUNDAY NIGHT INTO MONDAY AS
THE SYSTEM EXITS THE REGION. 75

Things could get interesting by Monday morning

[TheProfessor]

From what I can tell the clouds didn't clear today, keeping our temperature 8 degrees cooler than forecasted. Was that a result of the El Nino?

[TeamPlayersBlue]

http://www.wsi.com/blog/energy/transiti ... -new-year/

Bottom two maps

[srainhoutx]

There is still some spread within the ensemble mean via the Euro and GEFS. While there is some similarities to the November 21-22 event, the pattern is a bit different with less in the way of cold air. That said these pesky 5H lows tend to be a forecasting nightmare at this range and until the system nears California late week into the weekend as it enters the RAOB network, expect changes. It is noteworthy that this is likely the beginning of a very active parade of southern stream storms that will bring us into the Christmas/New Year timeframe with progressive colder air building in with each storm system. This +PDO/+PNA regime is going to be interesting to watch unfold.