SE TX/SW LA Winter WX - 2011-2012

[srainhoutx]

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
633 AM CST TUE FEB 1 2011

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
BRAZORIA COUNTY IN SOUTHEAST TEXAS...
CHAMBERS COUNTY IN SOUTHEAST TEXAS...
FORT BEND COUNTY IN SOUTHEAST TEXAS...
GALVESTON COUNTY IN SOUTHEAST TEXAS...
HARRIS COUNTY IN SOUTHEAST TEXAS...
SOUTHEASTERN JACKSON COUNTY IN SOUTHEAST TEXAS...
LIBERTY COUNTY IN SOUTHEAST TEXAS...
MATAGORDA COUNTY IN SOUTHEAST TEXAS...
EASTERN MONTGOMERY COUNTY IN SOUTHEAST TEXAS...
POLK COUNTY IN SOUTHEAST TEXAS...
SAN JACINTO COUNTY IN SOUTHEAST TEXAS...
EASTERN TRINITY COUNTY IN SOUTHEAST TEXAS...
SOUTHEASTERN WALKER COUNTY IN SOUTHEAST TEXAS...
SOUTHEASTERN WHARTON COUNTY IN SOUTHEAST TEXAS...

* UNTIL 730 AM CST

* AT 628 AM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS. THESE STORMS WERE LOCATED ALONG A
LINE EXTENDING FROM 10 MILES SOUTH OF CORRIGAN TO PALACIOS... MOVING
EAST NORTHEAST AT 50 MPH. THESE STORMS HAVE A HISTORY OF PRODUCING
WIND DAMAGE.

* LOCATIONS IN THE SEVERE THUNDERSTORM WARNING INCLUDE BUT ARE NOT
LIMITED TO TIKI ISLAND...THE MEDICAL CENTER...SPLASHTOWN...SMITH
POINT...SARGENT...ROLLOVER PASS...RELIANT PARK...PORT BOLIVAR...
MOODY GARDENS...MINUTE MAID PARK...LAKE LIVINGSTON STATE PARK...
KEMAH BOARDWALK...JOHNSON SPACE CENTER...HOOKS AIRPORT...HOBBY
AIRPORT...LA MARQUE...KINGWOOD...KEMAH...KATY...JONES
CREEK...JERSEY VILLAGE...JACINTO CITY...HUNTERS CREEK
VILLAGE...HUMBLE... HOUSTON...HOLIDAY LAKES...HITCHCOCK...
HIGHLANDS...HEDWIG VILLAGE... GALENA PARK...FRIENDSWOOD...FRESNO...
FREEPORT...FIRST COLONY...EL LAGO...DICKINSON...DEER
PARK...DAYTON...DANBURY...DAISETTA...CUT AND SHOOT...CROSBY...
CONROE...CLUTE...CLOVERLEAF...CLEVELAND... CLEAR LAKE
SHORES...CHANNELVIEW...BUNKER HILL VILLAGE...BROOKSIDE
VILLAGE...BRAZORIA...BOLING-IAGO...BELLAIRE...BAYTOWN...BAYOU
VISTA...BAY CITY...BARRETT...BACLIFF...ANGLETON...ANAHUAC...AMES...
ALVIN AND ALDINE.

[southerngale]

Wow. It's just gotten pitch dark here and the wind is whipping like crazy and it's pouring! Wow... loud thunder! I am just praying that my electricity stays on. With this wind, I'm not holding my breath. WOW it's so dark!

[srainhoutx]

Get ready. A 30 degree drop in an hour, here...

[southerngale]

My yard is flooded and it just started a little over 10 minutes ago. This rain is HEAVY! And coming down sideways. Wow... crazy wild!

[Tireman4]

Yep..what a drop...get ready

[srainhoutx]

College Station down to 36. Once this storm occludes, look out. Those temps will plummet later today.

[Tireman4]

Srain,

I am thinking mid 30's by 5 pm....are you thinking lower for Houston area..

[southerngale]

Don't see this every day!

Btw, temps have already dropped A LOT. The temp in the image is at the airport. My yard is a mess! Flooded and scattered "debris" including a tree branch snapped.

[Tireman4]

Don't see this every day!

Btw, temps have already dropped A LOT. The temp in the image is at the airport. My yard is a mess! Flooded and scattered "debris" including a tree branch snapped.

Goodness. Stay safe Gale

[srainhoutx]

Srain,

I am thinking mid 30's by 5 pm....are you thinking lower for Houston area..

Yep. I wouldn't be surprised to see near freezing here (my location) by late afternoon. Winds are starting to increase again after about 45 minutes of somewhat of a lull.

[southerngale]

Email from Jeff Lindner:

Memorable arctic outbreak arriving across the region this morning.



Hard Freeze Warning issued for all areas for tonight



Wind Advisory issued for all areas through late this evening



Winter Storm becoming likely Thursday night/Friday with accumulations of snow



Discussion:

Much talked about arctic outbreak is here with a powerful front cutting SE TX in half this morning with temperatures falling into the 30’s from the upper 60’s within a few minutes of the fronts arrival. Blizzard conditions ongoing over W TX into N TX and OK with howling NW winds (temperatures in the teens and 20’s, wind chills in the -10 to 0 range). In fact roughly 100 million residents across the plains and Midwest will see more than 1 foot of snow and blizzard conditions today.



Arctic boundary is way ahead of model timing and will be off the coast by 800-900am. Very strong NW winds of 30-40mph will develop behind the initial damaging winds along the leading edge of the squall line.



Will break out impacts for wind and temperatures and then break out forecast time periods below.



Wind Advisory:

Massive arctic surface high building down the plains will result in a powerful pressure gradient with very strong winds howling well into tonight. These winds will drive wind chills into the 1’s and 10’s this afternoon and evening (a rare experience for those this far south). Sustained NW winds of 25-35mph with frequent gusts of 45mph will be likely today and into tonight. Winds should finally begin to relax into the 15-20mph range early Wednesday.



Hard Freeze Warning:

Hard Freeze warning is in effect for the entire area (all counties) for tonight into Wednesday. Forecasting lows in the mid to upper 10’s over our northern counties to lower 20’s central to upper 20’s at the beaches and on the island. Areas north of HWY 105 will be below freezing for up to 20 hours, north of US 59 16 hours and along the coast 6-8 hours. Will see similar cold lows again on Thursday and Friday mornings.



Winter Storm Threat (Thursday/Friday):

Confidence is growing that a winter storm will affect the region Thursday night and Friday. Impressive upper level trough over the northern Rockies will drop southward into the base of the long wave trough over the SW US allowing the piece of energy to deepen into an upper level low. Cold arctic dome will be firmly entrenched over the region with forecast soundings showing freezing/subfreezing profiles for the entire area. ECMWF and CMC continue to be slower with the ejection of this trough and will side with the stronger and slower solution (GFS and NAM are fastest)> The GFS was too fast on the Sunday system and SW US upper troughs tend to eject slower than models project. The slower motion of the trough will allow a greater period of moisture to pool and advect into the 850-700mb region ahead of the trough. Feel the models (especially the GFS) is too dry in the 500-700mb layer (ice growth layer) and that more moisture than being shown will be available. Large scale deep layer lift will begin Thursday afternoon with increasing clouds and lowering cloud bases. Should start to see sleet/snow develop along the Rio Grande River and near Corpus Christi by early evening and then spread/develop N/E overnight. Combination of isentropic lift in the deep cold dome and potential for low to mid level frotogenic forcing points toward the formation of multiple meso scale snow bands (similar to Dec 2004). Surface dewpoints will be in the 10’s and low level dry layer will wet bulb as the precipitation starts keeping surface temperatures below freezing for the entire event. Far south, NW Gulf surface low will develop and has the potential to bring a slight 850mb warm nose back toward the coastal locations early Friday morning which may result in P-type changing to or mixing with IP (sleet). Dominant P-type will be snow for all other locations away from the beaches.



Accumulations:

Looks like we indeed will see accumulations with this event. CMC is by far the wettest model and the GFS the driest with the ECMWF in the middle. Will go wetter than the GFS but not as bad as the CMC just yet. Dec 04 snowstorm looked the same way on the models (moisture starved up until the event started and then bam). Looks like accumulations will be possible across the entire region with the best chances in a band from W of Corpus Christi to Victoria to Wharton. Still too early to talk totals, but a rough early estimate with a 10:1 ratio (usually we are closer to 7:1 down here, but with such cold temperatures the normal ratio may work out better) would be about 1-3 inches south of I-10 on the ground. If the CMC is correct we would be talking 6-8 inches across much of the area…a blizzard by our standards!



12-Hour Forecasts (Today through Friday):



North: along and north of a line from Brenham to Conroe to Livingston

Central: along and north of a line Victoria to Sugar Land to Humble to Liberty

South: inland coastal counties to US 59

Coastal: beaches



Today:

Showers and thunderstorms before noon following by rapidly falling temperatures. NW winds 30-35mph with gust of 45mph. Wind chills in the 10’s and 20’s early falling into the 1’s and 10’s by sunset. Temperatures falling into the 30’s all areas by mid afternoon and upper 20’s north.



Tonight:

Hard Freeze Warning in effect. Cloudy and windy with NW winds 20-25mph and gusty. Wind chills in the 1’s and 10’s.

Lows:

North: 16-19

Central: 20-24

South: 25-28

Coastal: 28-30



Wednesday:

Mostly cloudy and very cold with NW winds of 15-20mph.

Highs:

North: 30-34

Central: 33-37

South: 35-38

Coastal: 36-39



Wednesday night:

Mostly cloudy and very cold with NW winds of 10-15mph

Lows:

North: 17-20

Central: 22-25

South: 26-28

Coastal: 28-30



Thursday:

Increasing clouds and continued very cold. N winds 10-15mph

Highs:

North: 32-35

Central: 34-37

South: 35-38

Coastal: 36-40



Thursday night:

Cloudy with snow developing. Chance of snow 50%. Snow may mix with sleet near the coast and south of Victoria. Accumulations possible.

Lows:

North: 22-25

Central: 23-26

South: 25-28

Coastal: 29-31



Friday:

Cloudy with a 60% chance of snow, some snow may be heavy at times. Snow may mix with sleet early along the coast. Accumulations likely.

Highs:

North: 30-34

Central: 29-34

South: 30-33

Coastal: 31-34



Actions:

Preparations for an extended period of freezing weather should be completed at this time.

Hazardous driving conditions may develop Thursday night and early Friday as winter precipitation develops over the area.



TXDOT started applying anti-ice agent to freeways and flyovers in Montgomery County yesterday and these actions will be increased and expanded to other areas on Wednesday. Very cold ground temperatures will make this agent only somewhat effective. Believe the first amounts of snow early Friday will melt with the remaining little ground warmth and then freeze as a layer of ice on most surfaces and then snow will accumulate on top of this layer of ice making for very dangerous travel conditions. Unlike past events surface roads (not just bridges and overpasses) will likely be impacted given the cold ground when the event starts.



Active TXDOT Road Condition Map:


http://www.txdot.gov/gis/hcrs_main/viewer.htm



Aviation:

Significant travel impacts as US central plains blizzard impacts major airports across the Midwest, plains, and into the NE. Suspect some airports will close completely as snow removal operations will not be able to keep up with heavy snow/blowing snow. End of the week will bring our own problems locally with winter precipitation. Suspect de-icing of aircraft control surfaces will be required at all local airports by Thursday night which will result in long delays.

[vbhoutex]

BBBBBBBBBBBBRRRRRRRRRRRRRRR!!!!!!!!!!!!!!!!!
The temps leveled off around 40f earlier this morning. Now they have dropped 5 degrees and we are at 35f here at the house. The wind is up(25-30 w/ 40-45G w/ 47 G at nearest weatherbug)and the clouds appear to be thickening. Any ideas as to the reason for this?
edit @ 10:30-Still on a steady drop. thinking we will be at or below freezing by noon if this rate keeps up.

[CYCLONE MIKE]

I posted this on the deep south winter thread. It is the HPC's experimental snowfall and freezing rain forecast for up to 72 hours. You can click on amounts or timeframes on the right side of page. Anyway check out what it show for friday....

http://www.hpc.ncep.noaa.gov/pwpf_24hr/ ... obs_zr.php

[PTrackerLA]

Are the NOAA sites loading painfully slow for everyone else or is it just me?

[vbhoutex]

I posted this on the deep south winter thread. It is the HPC's experimental snowfall and freezing rain forecast for up to 72 hours. You can click on amounts or timeframes on the right side of page. Anyway check out what it show for friday....

http://www.hpc.ncep.noaa.gov/pwpf_24hr/ ... obs_zr.php

If I am reading that correctly.
And the weatherbug nearest to my house just hit 32f!!! I am certainly no pro-met, but this front has come in faster and stronger than expected by about 3-4hours and temps about 6 hours ahead of schedule. Thinking that we may be in for some lower temps than previously progged for the metro area. Upper teens even into the Beltway would not be a surprise to me. I wish the clouds would thicken some more and we could squeeze some flurries out of them. Guess I will have to wait a few days.

[CajunMama]

The squall line is here. Wind howling, torrential rain. I wouldn't want to be a duck out in this weather!

Edit @ 11:54am: Ok, it's over. Well, i could have been a duck for that short lived squall line!

[Hook'em Horns!]

I posted this on the deep south winter thread. It is the HPC's experimental snowfall and freezing rain forecast for up to 72 hours. You can click on amounts or timeframes on the right side of page. Anyway check out what it show for friday....

http://www.hpc.ncep.noaa.gov/pwpf_24hr/ ... obs_zr.php

Actually the snow forecast is more for central TX and not along the coast.

[vbhoutex]

I posted this on the deep south winter thread. It is the HPC's experimental snowfall and freezing rain forecast for up to 72 hours. You can click on amounts or timeframes on the right side of page. Anyway check out what it show for friday....

http://www.hpc.ncep.noaa.gov/pwpf_24hr/ ... obs_zr.php

Ok, now that I have read this closer, I am not so concerned. It is percentage that an ice accumulation might occur.

[vbhoutex]

Latest from Jeff:

Very cold arctic air mass building into the region.

At 1100am temperatures have fallen to freezing already from Hempstead to Conroe. Already 29 in College Station with a wind chill of 15. Will need to adjust temperatures downward for this afternoon to reflect rapid onset of freezing/sub-freezing air mass. Upstream temperatures at 1100am are 19 at DFW, 12 at Wichita Falls, and 2 at Amarillo. May also need to adjust overnight lows downward a few degrees for tonight with teens a bit further south and near 20 along US 59.

Strong winds will continue into this evening with wind chills falling into the 1’s and low 10’s.

Winter Storm event looking likely Thursday night and Friday with significant comparisons to the historic 2004 Dec snow event for coastal TX. This system looks wetter and colder than that event if you can believe that! Not ready to bite on very high QPF totals being generated by the CMC, but believe the GFS is too dry with its 1-2 inches over the area. Still going with a widespread 1-3” of snow accumulation south of I-10 with 1-2” north of I-10. Totals may need to be raised greatly over the next 24 hours if the CMC appears to be correct or the GFS trends wetter.

With confidence building in a snow pack on the ground for Friday night will likely need to lower overnight temperatures into the upper 10’s/low 20’s for all areas as skies clear out.

[PTrackerLA]

Temp dropped from 64 - 57 degrees in 4 minutes according to my vehicle. Yes I sat in it while the squall line came through just to watch the temperature . Since the cold air has reached us much quicker than predicted, I wonder if we have a greater shot at snow than currently forecasted. The NAM shows decent accumulations of snow JUST north of here.