February 1-5, 2011 Arctic Blast/Winter Storm Discussion

[Mr. T]

Wow, it is really blowing in Kingwood. Seeing transformer flashes.

Saw the same thing... That really cool blue green color

[wxman57]

Line appears to be strengthening on approach and becoming more uniform. Can't wait to see what winds gusts/temp drops I get out of this...

The greater moisture will be closer to the coast.

[srainhoutx]

30 degree drop in an hour up here.

[unome]

I hope the "unwise" stay off the roads later this week if we get sleet/snow

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

[ticka1]

While I was driving in from Baytown Mont Belvieu area on I-10 - as I approached downtown the temp was 70+ degrees - it started raining and wind blowing - saw several transformers blow near downtown and my temp dropped to 48 degrees when I parked in parking garage.

Its here folks.

[snowman65]

About what time should we expect to see temps falling in Orange/Bmt area?

[ronyan]

FROPA @ 7:20 am. About 4 hours earlier than I was thinking!

[wxman57]

About what time should we expect to see temps falling in Orange/Bmt area?

Rough estimate would be between 8:30 and 9.

[unome]

While I was driving in from Baytown Mont Belvieu area on I-10 - as I approached downtown the temp was 70+ degrees - it started raining and wind blowing - saw several transformers blow near downtown and my temp dropped to 48 degrees when I parked in parking garage.

Its hear folks.

bad time for ppl to lose electricity

major accident at 610 N, Eastbound, exit to 45N http://traffic.houstontranstar.org/layers/

[snowman65]

Thanks WXMAN!!.....at least school will already be in session so shouldn't be any traffic issues..

[Katdaddy]

Crazy morning so I did not check if this was already posted. From this mornings Hou-Gal AFD:

THERE IS A GROWING CONCERN FOR WINTER WEATHER ON BEGINNING
THRUSDAY NIGHT INTO FRIDAY. THE COLD FIGID AIRMASS WILL ALREADY
BE IN PLACE WITH OVERNIGHT LOW TEMPS IN THE 20S FOR MOST INLAND
AREAS AND JUST BELOW FREEZING ALONG THE COAST. A STRONG UPPER
LEVEL LOW THAT IS CURRENTLY DROPPING SOUTH OUT OF THE ROCKIES
TOWARDS THE 4 CORNERS REGION TODAY AND TOMORROW WILL THEN SWING
EAST THU/FRI. STRONG QG LIFT AND LARGE SCALE ASCENT WILL
ACCOMPANY THE SYSTEM. MESOSCALE FORCING IS A BIT MORE DIFFICULT
TO NAIL DOWN BUT THINK THERE WILL BE AT LEAST SOME LOW LEVEL
FRONTOGENESIS AND ISENTROPIC LIFT AS A COASTAL LOW DEVELOPS. ALL
OF THE MODELS ARE HINTING AT SOME SORT OF PRECIP THU NIGHT INTO
FRI SO BUMPED POPS UP INTO THE LIKELY (60 POP) CATEGORY. THINK
THERE IS GOOD CONSENSUS OF PRECIP OCCURRING AND GIVEN
TEMPS/MOISTURE PROFILES...MOST AREAS WILL HAVE SNOW. THERE MAY BE
A NOSE OF WARM AIR AROUND 850MB ALONG THE COAST THAT COULD
SUPPORT SLEET/SNOW MIX. STILL SOME TIME TO NAIL DOWN DETAILS AND
ACCUMULATIONS. AT THIS TIME...IF MODELS ARE CORRECT IN PRECIP
AMOUNTS...SOME AREAS SOUTH OF I-10 COULD SEE 1-3 INCHES OF SNOW.THE BEST TIME FOR FROZEN PRECIP WILL BE FROM 06 FRI TO 18Z FRI.
IT IS TOO FAR OUT FOR ANY KIND OF WINTER WEATHER WATCH BUT THAT
WILL BE THE NEXT STEP IN THE COMING DAYS IF FUTURE MODEL RUNS
CONTINUE TO SUPPORT WINTER PRECIP.

[ronyan]

Woah, that high at DFW tomorrow is supposed to be 16 F! Incredible. Windchill in Amarillo is currently -25 F with a temp of 1 F.

[txflagwaver]

WOW...wind not just strong, the whole house shuddered. Temp drop here...thunderstorms...

[srainhoutx]

[ticka1]

Did the front arrive earlier then what was forecasted in the models?

[snowman65]

[quote="Katdaddy"]Crazy morning so I did not check if this was already posted. From this mornings Hou-Gal AFD:

IF MODELS ARE CORRECT IN PRECIP
AMOUNTS...SOME AREAS SOUTH OF I-10 COULD SEE 1-3 INCHES OF SNOW.[/b]THE BEST TIME FOR FROZEN PRECIP WILL BE FROM 06 FRI TO 18Z FRI.


S of I-10??? That's unusual....I'm curious about us folks in Orange. Sounds fun to me

[ticka1]

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.

[srainhoutx]

Did the front arrive earlier then what was forecasted in the models?

Yes. The storm is an over achiever. It is out performing the model guidance by a lot.

[sleetstorm]

The current temperature here in Baytown already feels like it is in the 40's. Wow.

[srainhoutx]

Only in TX...64 degree temp differential...