January: Seasonal Temps To End The Month

[srainhoutx]

Morning e-mail from Jeff:

Mix of winter precipitation possible tonight for the northern parts of SE TX.

Another piece of energy currently approaching SW TX this morning will swing ENE tonight and Friday. Surface high pressure currently over NW TX has dried the area after the light rains yesterday, but moisture is lurking just to the SW and this will return to the region this afternoon and evening. Fairly decent lift is expected to affect the area north of I-10 after midnight tonight with precipitation banding developing from SC TX into SE TX.

Current soundings have a large dry layer just above the 900mb layer up to around 750mb or roughly 8000 ft thick at IAH to around 7500 ft thick at College Station. There is a significant dry layer with RH below 20% around the 850mb level. All of this dry air above the surface is important in attempting to determine what type of precipitation may fall tonight into Friday. The soundings yesterday morning were similar to today, yet a little more moist and there was just enough cooling in the mid levels from the evaporation of the precipitation falling to allow sleet to reach the ground although the temperature profile showed a extensive area of above freezing temperatures. Since the air is slightly drier this morning in the mid levels, some precipitation falling through this layer tonight will help cool the temperatures in this layer from the 35-38 degree range toward the 31-34 degree range across the northern parts of the region. The best potential for cooling will be north of a line from Columbus to The Woodlands to Livingston where lift will be strongest and enough precipitation falling to help bring the mid layer toward saturation. Using the wet bulb surface temperature the lowest surface temperature I could get was 33-34 at College Station on the forecast sounding early Friday morning…if the GFS and NAM have the correct surface temperature and dewpoint which compared to the current conditions they seem to be aligned well. A wet bulb temperature at BUSH IAH for Friday morning is closer to 36-37 degrees. (Wet bulb temperature is the process of cooling the air temperature toward the dewpoint as a result of bringing the air column toward saturation….RH of 100% this results in the temperature cooling and the dewpoint rising until the air becomes saturated).

So with all that said, the freezing layer above the surface will be shrinking overnight as precipitation falls into the dry air and cools the air to below freezing. The forecast soundings over our northern counties from College Station to Huntsville reduce the above freezing layer to less than 3000 ft thick early Friday, but maintain surface temperatures a few degrees above freezing. Think the warm layer will be short enough to allow a mix of sleet and rain in the region from College Station to Huntsville, it is possible that the lower air column could cool enough to allow all sleet in this area. Precipitation intensity is expected to be on the lighter side (less than .10 of an inch) which suggest little if any accumulation especially if surface temperatures remain in the 33-35 range. Could be a few spots that drop to 31-32 degrees under some heavier precipitation in the northern counties and this could result in some very minor accumulation on elevated surfaces. It must be stressed that only a trace of ice on bridges and overpasses can be extremely dangerous. Should the next round of models come in slightly wetter or cooler over this region, we would likely be into Winter Weather Advisory criteria…and the trend over the past 24 hours has been toward a wetter system.

North of a line from Columbus to Kingwood to Livingston, the air column will require more work as lift will be weaker in this area and the above freezing layer is much thicker. Given the fact that sleet fell yesterday, I would not be surprised to see a mixture of light rain and sleet north of the above mentioned line. Throughout this region surface temperatures will be in the mid 30’s and any sleet will melt on contact. South of this line most of what falls will be liquid with a few ice pellets.

Precipitation Types (Tonight-mid morning Friday):

College Station to Huntsville North: rain/sleet mix possibly changing to all sleet with some snow mix. Some minor accumulation possible

Columbus to Katy to Kingwood to Livingston North: rain/sleet mix. No accumulation

Columbus to Katy to Kingwood to Livingston South: mainly rain with a few sleet pellets. No accumulation

Profile temperatures should warm enough to return the area to all rain by midday Friday. Cloudy and cold conditions will continue into Saturday as the area remains under the grips of an active sub-tropical jet stream aloft. Could see a few showers continue into Saturday before finally clearing on Sunday.

Extended:
While much focus is currently on the short term…the extended will not be outdone as models are showing a potential big weather maker arriving early to mid next week. Shear and instability profiles are looking very favorable for what could be a fairly significant severe weather outbreak over TX including the threat for tornadoes. The system has many similarities to the 1-9-12 flooding and severe weather/tornado event, but even projected stronger wind fields.

[MontgomeryCoWx]

I find it a bit strange that we could have a January 9th, 2012 repeat on January 9th, 2013.

[wxman57]

I'm not seeing any significant chance for snow in Houston over the next few weeks. Just a few sleet pellets mixed in with cold rain later today/tonight. Similar to what we saw yesterday. Long-term, the GFS is indicating some colder air moving out of Canada around the 14th. I'm not seeing any indications of "extreme cold" here, but maybe lows into the upper 20s across Houston (maybe mid 20s). Keep in mind that climatologically, the month we typically get the most snow is February. Can't rule out any snow here later this month, but I currently see no indications of it happening.

[Portastorm]

It appears the winter weather event is beginning. NWSFO Austin/San Antonio is now receiving numerous reports from emergency managers of sleet falling in western San Antonio and at various locales to the west, southwest, south, and even northeast of the city.

[srainhoutx]

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
952 AM CST THU JAN 3 2013

...WINTER WEATHER ADVISORY FOR THE WESTERN HILL COUNTRY AND
EDWARDS PLATEAU TONIGHT THROUGH FRIDAY MORNING...

.A MID TO UPPER LEVEL TROUGH OF LOW PRESSURE WILL MOVE OUT OF THE
SOUTHWESTERN UNITED STATES ACROSS CENTRAL TEXAS TONIGHT. WITH COLD
AIR IN PLACE IN THE LOWER LEVELS OF THE ATMOSPHERE THIS SYSTEM
WILL BRING RAIN AND SNOW TO THE AREA. EXPECT PRECIP TO BEGIN AS A
MIXTURE DURING THE AFTERNOON AND CHANGE OVER TO SNOW BY AROUND 10
PM AND CONTINUE OVERNIGHT. WARM AIR ADVECTION DURING THE DAY
FRIDAY WILL CHANGE PRECIPITATION OVER TO RAIN BY AROUND NOON. BEFORE THE
CHANGE EXPECT SNOW ACCUMULATION RANGING FROM A DUSTING TO AROUND
ONE INCH WITH A FEW SPOTS HAVING A BIT MORE. THE HIGHER AMOUNTS
WILL BE IN WESTERN VAL VERDE COUNTY.

TXZ183>186-040000-
/O.NEW.KEWX.WW.Y.0001.130104T0600Z-130104T1800Z/
VAL VERDE-EDWARDS-REAL-KERR-
INCLUDING THE CITIES OF...DEL RIO...ROCKSPRINGS...LEAKEY...
KERRVILLE
952 AM CST THU JAN 3 2013

...WINTER WEATHER ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO
NOON CST FRIDAY...

THE NATIONAL WEATHER SERVICE IN AUSTIN/SAN ANTONIO HAS ISSUED A
WINTER WEATHER ADVISORY FOR SNOW...WHICH IS IN EFFECT FROM
MIDNIGHT TONIGHT TO NOON CST FRIDAY.

* TIMING...RAIN...SLEET AND SNOW WILL BEGIN THIS AFTERNOON AND
CHANGE TO SNOW LATE THIS EVENING.

* MAIN IMPACT...SNOW UP TO ONE INCH WILL MAKE DRIVING HAZARDOUS.

* OTHER IMPACTS...THERE IS SOME CHANCE THAT SNOW WILL BREAK OFF
WEAK TREE BRANCHES.

[srainhoutx]

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
618 AM CST THU JAN 3 2013

TXZ163-164-176>179-195>200-210>213-032000-
HOUSTON-TRINITY-MADISON-WALKER-SAN JACINTO-POLK-BURLESON-BRAZOS-
WASHINGTON-GRIMES-MONTGOMERY-LIBERTY-COLORADO-AUSTIN-WALLER-
HARRIS-
INCLUDING THE CITIES OF...CROCKETT...TRINITY...GROVETON...
MADISONVILLE...HUNTSVILLE...SHEPHERD...COLDSPRING...LIVINGSTON...
CORRIGAN...ONALASKA...CALDWELL...LAKE SOMERVILLE...
COLLEGE STATION...BRYAN...BRENHAM...NAVASOTA...THE WOODLANDS...
CONROE...WILLIS...LIBERTY...CLEVELAND...DAYTON...COLUMBUS...
EAGLE LAKE...WEIMAR...SEALY...BELLVILLE...HEMPSTEAD...
PRAIRIE VIEW...BROOKSHIRE...HOUSTON...PASADENA...KATY...TOMBALL...
HUMBLE
618 AM CST THU JAN 3 2013

...WINTER PRECIPITATION POSSIBLE FRIDAY MORNING...

AN UPPER LEVEL DISTURBANCE IS EXPECTED TO MOVE INTO SOUTHEAST
TEXAS FRIDAY MORNING WITH PLENTY OF MID AND UPPER LEVEL MOISTURE.
LOW LEVEL MOISTURE AND TEMPERATURE PROFILES IN THE ATMOSPHERE
BECOME FAVORABLE FOR RAIN AND SLEET OR JUST SLEET NORTH OF A
BRENHAM TO LIVINGSTON LINE INCLUDING AREAS FROM COLLEGE STATION TO
HUNTSVILLE. SLEET AND RAIN MIX WILL BE POSSIBLE FROM ABOUT 3 AM TO
12 PM FRIDAY FOR THESE AREAS. SO FAR ONLY A FEW HUNDREDTHS OF AN
INCH TO A TENTH OF AN INCH OF RAIN IS EXPECTED BUT NO ICE
ACCUMULATIONS ARE EXPECTED AT THIS TIME. IT WOULD NOT TAKE MUCH
SLEET ACCUMULATION TO MAKE ROADS...OVERPASSES AND BRIDGES SLICK
AND HAZARDOUS FOR TRAVEL. PLEASE MONITOR FORECASTS TODAY AND
TONIGHT FOR THE POSSIBILITY OF A WINTER WEATHER ADVISORY SHOULD
ICE ACCUMULATIONS BECOME POSSIBLE.

SHOULD LOW TO MID LEVEL AIR BECOME COLDER AND THE LOWER LEVELS OF
THE ATMOSPHERE BECOME MORE MOIST...SLEET AND RAIN WILL BE POSSIBLE
NORTH OF A SEALY TO KINGWOOD LINE FRIDAY MORNING. THIS WOULD
INCLUDE THE NORTHERN PORTIONS OF HARRIS COUNTY. RIGHT NOW RAIN
WILL BE THE MAIN PRECIPITATION TYPE BUT A FEW POCKETS OF SLEET MAY
BE POSSIBLE. NO ICE ACCUMULATIONS ARE EXPECTED FOR THE HOUSTON
AREA AT THIS TIME WITH MOST OF THE PRECIPITATION FALLING AS RAIN.

[srainhoutx]

EWX reports sleet has reached New Braunfels (NWS Office). Melting on contact.

[texoz]

Sun has been peaking through the clouds this am in Austin. Temp is around 42 degrees at 10:30am

[srainhoutx]

Sun has been peaking through the clouds this am in Austin. Temp is around 42 degrees at 10:30am

There were a few breaks in the clouds here in NW Harris County as well, texoz. It has now clouded over and temp is holding steady at 41F at this hour.

[wxman57]

12Z GFS says I get to enjoy a brief respite in the cold next Tuesday:

[MontgomeryCoWx]

anything over 40 isn't cold... 40-55 is cool. Get over 65 and it starts getting warm and over 75 is hot.

Anything over 85 is bull**** hell.

Let us enjoy our Winter and the prospects of true cold air later this month. You'll have your 8 months of Houston Hell once late March rolls around.

[Ptarmigan]

anything over 40 isn't cold... 40-55 is cool. Get over 65 and it starts getting warm and over 75 is hot.

Anything over 85 is bull**** hell.

Let us enjoy our Winter and the prospects of true cold air later this month. You'll have your 8 months of Houston Hell once late March rolls around.

It is winter. It is suppose to be cold and like it that way.

[harpman]

I tell you what folks, over here in the New Orleans area, we are colder today than yesterday. It's a little surprising and I don't think forcasted. The wind is biting! Hey, send some of your winter precip over here. No one is even hinting at it for our area.

[srainhoutx]

The forecasts haven't worked out too well to your W as well, harpman. The noisy sub tropical jet and this type of pattern usually creates a lot of problems as we are seeing.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1052 AM CST THU JAN 3 2013

.DISCUSSION...
BASED ON CURRENT RADAR TRENDS HAVE MADE SOME CHANGES TO THE GOING
GRIDS/FCST...MAINLY TO SPEED UP THE START TIME OF THE PCPN MOVING
IN FROM THE WEST. OTHERWISE CLOUDS ARE ALSO CONTINUING TO MOVE IN
FROM THE W/SW AND OUR BRIEF PEEK AT THE SUN APPEARS TO BE ALL BUT
OVER.

[harpman]

The forecasts haven't worked out too well to your W as well, harpman. The noisy sub tropical jet and this type of pattern usually creates a lot of problems as we are seeing.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1052 AM CST THU JAN 3 2013

.DISCUSSION...
BASED ON CURRENT RADAR TRENDS HAVE MADE SOME CHANGES TO THE GOING
GRIDS/FCST...MAINLY TO SPEED UP THE START TIME OF THE PCPN MOVING
IN FROM THE WEST. OTHERWISE CLOUDS ARE ALSO CONTINUING TO MOVE IN
FROM THE W/SW AND OUR BRIEF PEEK AT THE SUN APPEARS TO BE ALL BUT
OVER.

yeah, the sun is peeking out here too, Srain. It's just much colder than yesterday and it kinda caught me off guard. I guess those clouds approaching you will eventually overtake us again.

[srainhoutx]

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1143 AM CST THU JAN 3 2013

TXZ171>173-187>194-202>209-217>225-228-040000-
LLANO-BURNET-WILLIAMSON-BANDERA-GILLESPIE-KENDALL-BLANCO-HAYS-
TRAVIS-BASTROP-LEE-KINNEY-UVALDE-MEDINA-BEXAR-COMAL-GUADALUPE-
CALDWELL-FAYETTE-MAVERICK-ZAVALA-FRIO-ATASCOSA-WILSON-KARNES-
GONZALES-DE WITT-LAVACA-DIMMIT-
INCLUDING THE CITIES OF...LLANO...BURNET...GEORGETOWN...BANDERA...
FREDERICKSBURG...BOERNE...BLANCO...SAN MARCOS...AUSTIN...
BASTROP...GIDDINGS...BRACKETTVILLE...UVALDE...HONDO...
SAN ANTONIO...NEW BRAUNFELS...SEGUIN...LOCKHART...LA GRANGE...
EAGLE PASS...CRYSTAL CITY...PEARSALL...PLEASANTON...FLORESVILLE...
KARNES CITY...GONZALES...CUERO...HALLETTSVILLE...CARRIZO SPRINGS
1143 AM CST THU JAN 3 2013

...WINTER WEATHER POSSIBLE TONIGHT THROUGH NOON FRIDAY ACROSS THE
EDWARDS PLATEAU...HILL COUNTRY...AND ADJACENT PARTS OF SOUTH CENTRAL TEXAS...

AN UPPER LEVEL STORM SYSTEM LOCATED OVER NORTHERN MEXICO AND THE
DESERT SOUTHWEST WILL MOVE NORTHEASTWARD ACROSS TEXAS OVER THE NEXT
24 HOURS. THIS WILL RESULT IN INCREASING PACIFIC MOISTURE ACROSS
SOUTH CENTRAL TEXAS.

A MIX OF LIGHT RAIN AND SNOW WILL BEGIN ACROSS THE EDWARDS PLATEAU
THIS EVENING. THE RAIN AND SNOW MIX WILL TRANSITION TO ALL SNOW
AFTER MIDNIGHT WHILE SPREADING EASTWARD ACROSS THE HILL COUNTRY
TOWARDS THE AUSTIN METRO AREA WHERE IT IS EXPECTED TO REMAIN MIXED
PRECIPITATION. FRIDAY MORNING SOME LIGHT SLEET MAY ALSO MIX WITH
THE RAIN AND SNOW FROM THE BALCONES ESCARPMENT SOUTHWARD TO
HIGHWAY 90. THE WINTER WEATHER EVENT WILL END AROUND NOON FRIDAY
AS THE AIRMASS BECOMES SATURATED AND TEMPERATURES WARM TO ABOVE
FREEZING FROM THE BASE OF THE CLOUD DECK DOWN TO THE SURFACE. A
WINTER WEATHER ADVISORY IS IN EFFECT FOR VAL VERDE...
EDWARDS...REAL...AND KERR COUNTIES FOR SNOW UP TO ONE INCH.
OUTSIDE OF THE ADVISORY AREA NO ACCUMULATION IS EXPECTED.

[srainhoutx]

Reports via NWS San Antonio/Austin: snow falling in Kerrville and Boerne

[srainhoutx]

MESOSCALE DISCUSSION 0001
NWS STORM PREDICTION CENTER NORMAN OK
1210 PM CST THU JAN 03 2013

AREAS AFFECTED...SRN NM THROUGH SWRN TX

CONCERNING...HEAVY SNOW

VALID 031810Z - 032315Z

SUMMARY...OCCASIONAL MODERATE TO HEAVY SNOW WITH RATES LOCALLY UP TO
1 INCH PER HOUR IS EXPECTED TO PERSIST INTO THE EARLY EVENING ACROSS
SRN NM INTO WEST TEXAS. TENDENCY SHOULD BE FOR HEAVIER SNOW TO
DEVELOP FARTHER SWD TOWARD THE BIG BEND AREA OF SW TX LATER THIS
AFTERNOON OR EVENING.

DISCUSSION...AREAS OF SNOW WITH EMBEDDED BANDS OF LOCALLY MODERATE
TO HEAVY SNOW CONTINUES WITHIN A BROAD ZONE OF WARM ADVECTION FROM
SRN NM THROUGH WRN AND SWRN TX. THE PRECIPITATION HAS INCREASED IN
COVERAGE AND INTENSITY THROUGH THE MORNING IN ASSOCIATION WITH A
SHORTWAVE TROUGH MOVING ENEWD THROUGH NRN MEXICO. THE 12Z RAOB FROM
EL PASO INDICATED AN UNSTABLE LAYER BETWEEN 600 AND 400 MB
SUGGESTING SOME CONVECTIVE ENHANCEMENT IS LIKELY OCCURRING. AN UPPER
JET STREAK LOCATED OVER NRN MEXICO WILL SHIFT NEWD TOWARD THE BIG
BEND THIS EVENING. THIS FEATURE WILL CONTRIBUTE TO INCREASING ASCENT
WITHIN DENDRITIC GROWTH LAYER...LIKELY AUGMENTING SNOWFALL RATES
FROM THE MOUNTAINS OF SWRN TX INTO THE BIG BEND AREA LATER THIS
AFTERNOON AND EVENING.

..DIAL.. 01/03/2013


ATTN...WFO...SJT...MAF...ABQ...EPZ...

[unome]

WeatherNation's blog talks about it: BIG Snow in Texas and Cold Nationally

http://blog.weathernationtv.com/2013/01 ... ationally/

adding the link to El Paso NWS' Video Nowcast

http://youtu.be/bMRWQm4ZJV0

[srainhoutx]

While we are looking to our West this afternoon and following the potential severe event next week, the GEFS (GFS Ensembles) and Euro continue to advertise after our brief warm up a 'colder' and stormy pattern will return.

01032013 12Z GEFS 12zgfsensembles500mbHeightAnomalyNH240.gif

01032013 Euro 12zeuro500mbHeightAnomalyNH240.gif