TX Winter WX Thread #6 - An Icy and Rough Weekend Ahead

[TexasStooge]

Previous thread:
http://www.storm2k.org/phpbb2/viewtopic.php?t=92245


Picking up where the 5th thread left off: While North and Central Texas gets freezing rain and sleet, the TX panhandle will have the works (snow included). Thus prompting the NWS offices to issue Winter Storm Watches for the Panhandle and areas Northwest of North Texas including Vernon and Wichita Falls.

.TEMPERATURES WILL FALL BELOW FREEZING RAPIDLY ON FRIDAY INTO
FRIDAY EVENING...AT THE SAME TIME THAT MOISTURE INCREASES AHEAD OF
AN UPPER LEVEL STORM. ALTHOUGH SLEET AND SNOW WILL BE
POSSIBLE...MOST OF THE PRECIPITATION WILL FALL AS LIGHT AND
OCCASIONALLY MODERATE FREEZING RAIN. CONDITIONS WILL DETERIORATE
IN WESTERN NORTH TEXAS THROUGH SOUTHERN AND CENTRAL OKLAHOMA AS
EARLY AS FRIDAY AFTERNOON...LASTING THROUGH FRIDAY NIGHT. LIGHTER
FREEZING DRIZZLE IS EXPECTED IN NORTHERN AND WESTERN
OKLAHOMA DURING THIS TIME...BUT PRECIPITATION WILL BECOME HEAVIER
ACROSS THE ENTIRE REGION AGAIN SATURDAY NIGHT INTO SUNDAY AS THE
MAIN UPPER STORM COMES THROUGH THE AREA.

BY SUNDAY EVENING...ICE ACCUMULATIONS MAY RANGE FROM A QUARTER
INCH TO WELL OVER ONE INCH. AT THIS TIME...THE HEAVIEST
ACCUMULATIONS APPEAR LIKELY ALONG AND SOUTH OF THE INTERSTATE 44
CORRIDOR FROM WICHITA FALLS THROUGH OKLAHOMA CITY...INCLUDING A
LARGE PART OF SOUTHERN OKLAHOMA.

GUSTY WINDS WILL ALSO BRING BITTERLY COLD WIND CHILLS AND THE
POSSIBILITY FOR DOWNED TREES AND POWER LINES...LEADING TO POWER
OUTAGES.

THIS WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT
ICE ACCUMULATIONS THAT MAY IMPACT TRAVEL AND POWER. CONTINUE TO
MONITOR THE LATEST FORECASTS.

A MIXTURE OF FREEZING RAIN AND SLEET IS EXPECTED TO SPREAD ACROSS
THE PANHANDLES FRIDAY NIGHT AND CONTINUE INTO SATURDAY BEFORE MIXING
WITH AND CHANGING TO SNOW SATURDAY NIGHT INTO SUNDAY MORNING. TOTAL
ICE ACCUMULATIONS AROUND ONE HALF OF AN INCH WILL BE POSSIBLE.
SNOWFALL ACCUMULATIONS ARE EXPECTED TO BE LESS THAN 2 INCHES.

THERE STILL REMAINS SOME UNCERTAINTY ABOUT THE TRACK OF THE UPPER
LEVEL STORM...THEREFORE ICE AND SNOW FORECAST ACCUMULATIONS MAY CHANGE.

A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT
SNOW...SLEET...OR ICE ACCUMULATIONS THAT MAY IMPACT TRAVEL.
CONTINUE TO MONITOR THE LATEST FORECASTS.

NWS Forecasts:

AMARILLO
Friday: 34°F | 18°F
Saturday: 27°F | 20°F
Sunday: 25°F | 9°F
_____________________________________________________________

LUBBOCK
Friday: 53°F | 28°F
Saturday: 33°F | 26°F
Sunday: 34°F | 17°F
_____________________________________________________________

WICHITA FALLS
Friday: 60°F | 27°F
Saturday: 29°F | 22°F
Sunday: 32°F | 18°F

Morning Ensembles on Sunday:
http://www.cdc.noaa.gov/map/images/ens/ ... 2_usbg.gif

The cold front is still trying to push south:
http://www.hpc.ncep.noaa.gov/sfc/satsfcnps.gif

Map of Current Temperatures:
http://www.weatherimages.org/data/imag226.html
Of course, I don't recall DFW being at -2°F at this time.

*edited by staff to include link to previous thread

[jeff]

Arctic outbreak surging into the N US.

Threat of freezing rain and sleet increasing once again.

As suspected yesterday the models continue to perform poorly and will not rely on much if any of the guidance.

Discussion:

Upper trough digging across the western US unleashing cold arctic air southward with origins from Siberia and N Russia. Current temps are -6 at Cutbank. MT and 1 at Bozeman, MT. Arctic boundary will push southward reaching the TX panhandle late Friday as massive 1050mb arctic high dams against the front range of the Rockies. Bitter cold air will drop down the plains with near 0 readings as far south as KS by Saturday.

Frontal Timing:

Our friend the GFS model has pushed back the front’s arrival until midnight Sunday across SE TX. This is likely too slow as arctic air masses usually arrive sooner than model guidance suggests. Expect the front to enter the northern counties early Sunday morning and be off the coast by mid afternoon. This timing is about 4-6 hours slower than I suggested yesterday, however I would not be surprised if the front came through between 600am and noon Sunday (metro Houston). Temps. in the 70’s will plummet with the frontal passage…dropping quickly into the 30’s under impressive surface cold air advection. Winds will gust over 30mph and wind chills will crater into the 20’s by Sunday night. Will likely see gale force conditions over the waters as strong arctic high pushes southward.

Temps:

Will once again toss guidance in the trash as it is nearly useless for temps. with this air mass. The intensity of this air mass is not to be ignored and proper precautions to protect plants and pipes should be taken this weekend. Will undercut the GFS numbers by at least 10-15 degrees on the highs and 2-4 degrees on the lows. Expect surface temps. to fall below freezing early Monday morning, possibly Sunday evening (northern counties) and remain at or below 33-35 through midday Wednesday. With threat of thick overcast and freezing/frozen precip. temps. may hover in the upper 20’s and low 30’s through the entire period.

Precip/P-type:

As I suggested yesterday, “I would not be surprised if the models flip flopped back to a wetter trend” and one could imagine my surprise this morning when that is exactly what has happened overnight. GFS and ECMWF show a deeper and slower upper trough behind the arctic boundary allowing overrunning rains post front into freezing and sub-freezing surface layers. Will onset freezing rain late Sunday night northern counties and drop the line southward during the day Monday toward metro Houston. Expected freezing rain mixing with sleet Monday afternoon through much of Tuesday along and N of US 59. Cold air deepens some on Tuesday and freezing rain may change to more sleet by afternoon. Will hold back on freezing rain south of US 59 for the moment, but would not be surprised to need southward adjustments to mesh with KCRP forecast of freezing rain into Victoria Co. In fact may need to go with freezing rain all locations except coastal tier counties on Tuesday.

Accumulations:

Very tough call here as much depends on the surface temps and of course the amount of QPF. Per guidance most of what falls looks to be fairly light, however when dealing with freezing rain…a very small amount can go very far in causing big problems. Expect areas along and north of I-10 to see the greatest amounts as that is where the temps. will be below freezing the longer period of time. Feel the best QPF will be south of I-10 and the coldest temps. north which may allow folks N of I-10 to escape significant icing.

Preparations:

Residents should begin to make preparations for an extended period of very cold weather. Outside pipes should be wrapped and covered and sprinkler systems shut off. Tropical plants will need to be wrapped and firmly supported…ice accumulation on protective wrapping could become very heavy damaging the plant. Road conditions will go downhill quickly with the onset of freezing/frozen precip. with bridges and overpasses icing first followed by less traveled surface streets. Travel may become very difficult by late Monday into midday Wednesday as ice accumulates and mixes with sleet.


As has been noted the last several days, large forecast changes can be expected up until the time of the event. P-type and accumulation amounts as well as temps. will continue to be redefined over the next few days. I suspect A Winter Storm Watch may be needed by Sunday for a portion of SE TX.

Persons should stay alert to the forecast over the next few days and be prepared for hazardous driving conditions and extended cold temps. early next week.

[ETXHAMXYL]

Hey JEff I like your post, could you tell us what you expect for us folks up in NTX or ETX can expect? I live in NTX but we are also considered ETX. ABout 75m se of big D and not far from Tyler TExas.
Tyler forecast has us warmer and less ice and Dallas has us colder and more ice. Guess we are sitting on the fence line.

I will probably have to look at my weather rock outside after this all comes to pass to see if it is wet or frozen. LOL

[TrekkerCC]

NWS Ft. Worth office is wisely taking a wait and see approach as they state in the latest morning discussion. I do see to the Northwest of the DFW metro area that NWS Norman has already raised Winter Storm Watches, it will be interesting if NWS FWD will do the same thing at some point (Winter Storm Watch or Winter Weather Advisory).

DISCUSSION...
319 AM
STILL NO CONSENSUS BY THE MODELS. HAVE KEPT TEMPERATURES BETWEEN
THE COLDER NAM AND WARMER GFS...THINKING THAT THE GFS IS STILL
STUCK ON BRINGING A WAVE ACROSS THE FRONT TO HOLD UP THE COLD
AIR...AND AIR THAT COLD WILL NOT BE HELD UP BUT WILL HEAD ON SOUTH
MORE LIKE THE NAM IS FORECASTING. GFS HAS LESS OF A WAVE THAN
YESTERDAY/S RUN SO IT MAY BE MOVING MORE TOWARDS THE NAM/S
SOLUTION. GFS RUN TO RUN CONSISTENCY FOR NEXT WEEK IS STILL
POOR...IT BRINGS A MONDAY AFTERNOON DISTURBANCE OVER THE HILL
COUNTRY WHEN YESTERDAY IT HAD THE DISTURBANCE OVER THE GULF.

AS IS USUAL...WE ARE RIGHT ON THE EDGE OF THE WINTER WEATHER AND
MODEL ACCURACY IS NOT WHAT WE NEED TO PIN DOWN THE FORECAST. THE
NAM HAS US COLDER BUT DRIER...GFS IS WETTER BUT WARMER. FLIP A
COIN...ROLL THE DICE...TAKE YOUR CHANCES. FORECASTING WINTER
WEATHER HERE IN NORTH TEXAS IS A LOT LIKE POLITICS...IT/S BEST TO
JUST STAY ON THE FENCE AS LONG AS POSSIBLE BEFORE COMMITTING TO
ANYTHING. 84

[Portastorm]

It won't surprise me at all to see a fair portion of the state under Winter Storm Watches or Warnings by Sunday morning.

[CaptinCrunch]

It won't surprise me at all to see a fair portion of the state under Winter Storm Watches or Warnings by Sunday morning.

I expect a Winter Weather advisory to be issued for NCTX starting early Saturday morning, and Winter Storm Warning for later that evening. Now for the precip chances?

I got the FOOTBALL ready!!

[Portastorm]

It won't surprise me at all to see a fair portion of the state under Winter Storm Watches or Warnings by Sunday morning.

I expect a Winter Weather advisory to be issued for NCTX starting early Saturday morning, and Winter Storm Warning for later that evening. Now for the precip chances?

I got the FOOTBALL ready!!

Hey Captin, I hope we all get to kick the football this time!

The arctic front continues to make good progress and is halfway through Nebraska and well into Colorado:

http://www.wunderground.com/US/Region/U ... ature.html

[gboudx]

I'd prefer not to run and try to kick a football if it's ice that I'm running on. Somebody could get hurt.

[gboudx]

CC, and all it would take is for the system to be positions a little further south, and then that would be our problem. Let it stay up there.

[CaptinCrunch]

CC, and all it would take is for the system to be positions a little further south, and then that would be our problem. Let it stay up there.

You are right about that!! However I just have that unsetteled gut feeling that NCTX will get it's share of the Ice, Wichita Falls is just 4 hrs away and I don't see any reason why the WE won't get in on the wintery precip as well. Front is moving South at a good clip, it has to be for Norman to issue WSW less than 24hrs from yesterdays AFD.

[CaptinCrunch]

NWS AMARILLO TX
JAN 11 2007

DISCUSSION...
VERY COMPLICATED FORECAST HAS ME RUNNING A LITTLE LATE THIS MORNING.
BIG CHANGES ARE ON THE WAY FOR THE PANHANDLES AND THOSE CHANGES WILL
TAKE PLACE SOONER RATHER THAN LATER. CURRENT ANALYSIS SHOWS INITIAL
COLD FRONT ALREADY INTO WESTERN NEBRASKA AND NORTHEAST COLORADO THIS
MORNING. THIS FRONT IS EXPECTED TO CONTINUE RACING SOUTH AND SHOULD
BE INTO THE OKLAHOMA PANHANDLE AS EARLY AS LATE AFTERNOON.

[/b]

[TrekkerCC]

CC, and all it would take is for the system to be positions a little further south, and then that would be our problem. Let it stay up there.

A ice storm would not be fun to be in. I wish that the system out west would have held up till when we actually had some decent cold air in place at all levels. Right now, from looking at the forecast soundings, if we get freezing precipitation, it is probably going to be freezing rain. Good thing is that the ground is probably still relatively warm, through we have had some cold nights lately. I'm still in the watch and see mode, as the situation is on the borderline, with us possibly missing it this time around.

[Portastorm]

The 12z GFS run is coming in and the news is not good.

By 72 hours, the model depicts a fairly stout surface low in west Texas with a good swath of precip statewide. The temp profiles close to the surface have to be thrown out once again as they show the arctic boundary hung up in the Texas panhandle at 72 hrs ... but the trend of more significant precip has me concerned.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... /fpc.shtml

[CaptinCrunch]

CC, and all it would take is for the system to be positions a little further south, and then that would be our problem. Let it stay up there.

A ice storm would not be fun to be in. I wish that the system out west would have held up till when we actually had some decent cold air in place at all levels. Right now, from looking at the forecast soundings, if we get freezing precipitation, it is probably going to be freezing rain. Good thing is that the ground is probably still relatively warm, through we have had some cold nights lately. I'm still in the watch and see mode, as the situation is on the borderline, with us possibly missing it this time around.

Trekker,

Even though we have had chilly nights the ground is still very moist from all the recent rain, it wouldn't take much freezing rain to rapidly cool the ground and start to coat it with ice, plus the air temp right above it would be right at freezing. Remember Thanksgiving 93' started out with the same forecast.

[CaptinCrunch]

The 12z GFS run is coming in and the news is not good.

By 72 hours, the model depicts a fairly stout surface low in west Texas with a good swath of precip statewide. The temp profiles close to the surface have to be thrown out once again as they show the arctic boundary hung up in the Texas panhandle at 72 hrs ... but the trend of more significant precip has me concerned.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... /fpc.shtml

Heres the BIG rub!! Models do show more precip then past runs, which I beleive to be correct (I was out side at midnight taken the dogs potty and notice how fast the clouds were moving to the North at the lower levels) add that to the fact the Arctic front is futher south than models show and with no signs of slowing down. If front moves into the Panhandels of TX OK by late afternoon ALL CURRENT forecast are out the window!!

[Stratosphere747]

The 12z GFS run is coming in and the news is not good.

By 72 hours, the model depicts a fairly stout surface low in west Texas with a good swath of precip statewide. The temp profiles close to the surface have to be thrown out once again as they show the arctic boundary hung up in the Texas panhandle at 72 hrs ... but the trend of more significant precip has me concerned.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... /fpc.shtml

I am almost onboard....

The moisture profiles are beginning to have me worried as well. Not sure about the Houston area yet, but North and Central Texas could have some issues.

[Portastorm]

The 12z GFS run is coming in and the news is not good.

By 72 hours, the model depicts a fairly stout surface low in west Texas with a good swath of precip statewide. The temp profiles close to the surface have to be thrown out once again as they show the arctic boundary hung up in the Texas panhandle at 72 hrs ... but the trend of more significant precip has me concerned.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... /fpc.shtml

I am almost onboard....

The moisture profiles are beginning to have me worried as well. Not sure about the Houston area yet, but North and Central Texas could have some issues.

Wow Strat! If we can get you onboard ... them I'm really sold that we're heading down an icy path! I know you're usually conservative on these things (and with good cause).

[Stratosphere747]

A little snippet from the earlier Houston disco. Look for the locals in Houston to become more concerned in their forecasts at noon and this evening.


WITH THE 00Z ECMWF AND THE 00Z GFS BOTH PROGGING A 500MB TROUGH
DEEPENING ACROSS THE SOUTHWEST UNITED STATES/NORTHERN MEXICO
MONDAY AND BOTH PROGGING CONSIDERABLE LOW TO MID LEVEL MOISTURE
ACROSS THE COASTAL SECTIONS OF TEXAS BEHIND THE FRONT...BELIEVE A
SLIGHT CHANCE TO CHANCE OF PRECIPITATION IS WARRANTED FOR MONDAY
AND TUESDAY. THE TOUGHER QUESTION IS THE TYPE OF PRECIPITATION AND
WITH GFS SOUNDINGS INDICATING NEARLY SATURATED AIR
ALOFT...TEMPERATURES NEAR OR BELOW FREEZING ALOFT AND NEAR THE
SURFACE...THE POSSIBILITY OF MIXED PRECIPITATION IS LIKELY WITH
LIGHT RAIN/SLEET/FREEZING RAIN ACROSS NORTHERN AND CENTRAL
PORTIONS OF THE CWA...LIGHT RAIN/SLEET ELSEWHERE. WITH
TEMPERATURES LIKELY NEAR OR BELOW FREEZING ACROSS NORTHERN
PORTIONS OF THE CWA MON NIGHT/TUES MORNING...MORE FROZEN
PRECIPITATION IS LIKELY THAN MIXED. AS THE LOW TO MID LEVEL
MOISTURE DIMINISHES TUES NIGHT...THE CHANCE OF MIXED PRECIPITATION
SHOULD COME TO AN END WITH DRIER AIR FILTERING INTO SOUTHEAST TX
WEDNESDAY. 32

[teal61]

I was just looking at the 06z DGEX, which is basically an extended run of the NAM. On its accumulated snowfall charts, its shows up to an inch all the way to the Texas gulf coast in the late Monday thru Wednesday time frame.

All the newer runs are starting show more moisture available during this time frame the only question is how cold will it be since they all seem to be handling the movement of the cold air poorly.

[Portastorm]

Winter Storm Watches now up in portions of the Texas panhandle.

http://www.srh.noaa.gov/lub/