SE TX/SW LA Winter WX - 2011-2012

[southerngale]

Big difference so far, between KBMT 12 and Fox 4 in Beaumont. KFDM only goes out 5 days and ends on Tuesday, so I didn't post it.

And sadly, but not surprisingly, no winter fun forecast. Just a wasted day of cold forecast by KBMT. lol

[Tireman4]

It's looking mighty wet this weekend...

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
550 AM CST FRI JAN 28 2011

.DISCUSSION...
SOUTHERN BRANCH BRINGING CIRRUS TO THE REGION THIS MORNING AND
SHOULD MOST OF THE MORNING. A VERY PLEASANT DAY WILL BE ON TAP.
UPPER LOW WEST OF BAJA WILL START MOVING EAST AND WILL TAP INTO
RATHER RICH GULF MOISTURE SATURDAY. MODEL SOUNDINGS INDICATE A
RAPID INCREASE IN MID AND HIGH CLOUDS DURING THE MORNING SATURDAY
AND THEN LL MOISTURE RAMPS UP QUICKLY DURING THE AFTERNOON WITH
RAIN CHANCES INCREASING QUICKLY DURING THE AFTERNOON AS WELL FROM
WEST TO EAST. ISOLATED THUNDERSTORMS POSSIBLE. SATURDAY NIGHT
LOOKING WET AS 1-1.4" PW ARRIVE WITH THE S/W SWEEPING THROUGH
AROUND SUNRISE...HIGH POPS ARE IN ORDER. MODERATE WAA IN
PLACE...INSTABILITY WILL BE SLIM BUT LI OF 0 TO -2 POSSIBLE/CAPE
LESS THAN 400 J/KG. THE NAM/GFS/ECMWF ALL DISAGREE ON THE TRACK OF
THE HEAVIEST RAIN AMOUNTS...GFS HITS THE NORTHERN CWA HARD AROUND
06Z SUN...ECMWF NORTHWEST TO THE SOUTHEAST 06-15Z (AND WITH BETTER
INSTABILITY) AND THE NAM CENTRAL 8-18Z. IN THIS FORECAST HAVE
FAVORED THE HEAVIER PRECIP OVER THE CENTRAL AND SOUTHERN AFTER
MIDNIGHT. RAINS SHOULD BE TAPERING OFF IN THE MORNING AND LIKELY
BY 10 AM FOR THE HOUSTON AREA BUT AREAS TO THE EAST MAY STILL HAVE
SHRA THROUGH EARLY AFTERNOON. SOME LINGERING INSTABILITY WITH
DAYTIME HEATING BUT SUBSIDENCE IN THE WAKE OF THE LOW SHOULD
INHIBIT ANY LATE AFTERNOON DEVELOPMENT.

Ahh man.. the Houston Marathon. I have friends both the half and full. Fun.......

[gboudx]

Ahh man.. the Houston Marathon. I have friends both the half and full. Fun.......

Lindner had this in his morning email.

Sunday Houston Marathon:

Best chance of rainfall with the weekend system appears to be aligning with the weekend run. Heavy rainfall and thunderstorms will be possible with temperatures in the 50’s and 60’s.

[Stormcenter]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
326 PM CST FRI JAN 28 2011

.DISCUSSION...
SURFACE HIGH PRESSURE OFF THE SOUTH TEXAS COAST HAS US IN A
UNSEASONABLY WARM PATTERN THROUGH THE WEEKEND. A MID- LEVEL
SHORTWAVE WILL EJECT OUT OF THE SW US SATURDAY NIGHT INTO
SUNDAY...RAPIDLY INCREASING OUR RAIN CHANCES...AND EVEN SOME
THUNDER. MODELS IN PRETTY GOOD AGREEMENT ON AROUND ONE INCH OF QPF
WITH THIS SYSTEM.

AFTER A SHORT BREAK ON MONDAY...A STRONG COLD FRONT WILL WORK ITS
WAY ACROSS THE REGION...AND EARLY INDICATIONS SHOW THIS SYSTEM HAS
THE POTENTIAL TO PRODUCE SOME STRONG TO SEVERE STORMS...SO WILL
ADD THIS TO THE HAZARDOUS WEATHER OUTLOOK. AS USUAL...WILL BE
WATCHING SVR ENVIRO...ESPECIALLY INSTABILITY...THAT MANY TIMES SEEMS
TO LIMIT ON SEVERE STORMS ALONG GULF COAST.

A STRONG RIDGE OF HIGH PRESSURE IS INDICATED BY 12Z ECMWF AND 12Z
GFS FOR THE WEDNESDAY THROUGH FRIDAY TIME FRAME. SIGNIFICANT
DIFFERENCES ON THE TEMPERATURES...THOUGH. TRENDED OUR TEMPS COLDER
THAN GFS...BUT NOT AS COLD AS EURO...BUT WILL HAVE TO WATCH TO SEE
IF THEY VERIFY BECAUSE IT WOULD BE ANOTHER HARD FREEZE FOR MUCH OF
THE REGION THU OR FRI MORNING...SO STAY TUNED.

[vbhoutex]

Has anyone taken a look at the HOU/GAL NWS weather graphics for temps this week? Weds., Thurs., Fri. are way past frigid!!! We are talking temps going down into the low to mid teens in some areas with lows areawide in the low 20's at best for Weds. and thurs. The high for Weds. looks like about 30f. Everyone needs to get their HARD FREEZE preparations in order NOW!!

edit @ 9:30pm-NWS graphics have been warmed at least 8 degrees if not more. I am not sure what model they are following, but we are still talking long hours below freezing and probably at least 2 hard freezes Weds-Sat. The graphics show freezes each morning weds thru sat with temps at the most getting into the low 40's each day. Personally, from what I am seeing in the models I am more inclined to believe the earlier temps I saw. I sure don't want it that cold but the models are sure showing a true arctic blast into all of Texas Tuesday evening through Saturday morning.

[srainhoutx]

It's getting close to time for the Frick and Frack snow thread...

[Tireman4]

Is not the HGX NWS notoriously conservative?

[southerngale]

Is not the HGX NWS notoriously conservative?

NWS LCH is and so far, they're not forecasting anything colder than what we've already seen this winter, highs or lows. Either they're waiting until it gets closer or I guess they don't expect it to be the coldest of the season here... not sure which.



My forecast tracker:

Tuesday: Rain and possibly a thunderstorm before noon, then a chance of rain and thunderstorms after noon. Some of the storms could produce gusty winds and heavy rain. High near 65. South wind around 15 mph becoming west. Winds could gust as high as 20 mph. Chance of precipitation is 80%.

Tuesday Night: Mostly cloudy, with a low around 26. North wind between 10 and 15 mph, with gusts as high as 20 mph.

Wednesday: Partly sunny, with a high near 44. North wind between 10 and 15 mph.

Wednesday Night: Partly cloudy, with a low around 24. North wind around 10 mph.

Thursday: Partly sunny, with a high near 42. North wind between 5 and 10 mph.

Thursday Night: Mostly cloudy, with a low around 24. North wind between 5 and 10 mph.

Friday: A 20 percent chance of showers. Partly sunny, with a high near 48.

Friday Night: Mostly cloudy, with a low around 31.

Saturday: Sunny, with a high near 54.

[southerngale]

My weather alert just went off. I thought the rain was over for the day. If this storm holds together, it should eventually get here.

Severe Thunderstorm Warning

SEVERE THUNDERSTORM WARNING
TXC199-310215-
/O.NEW.KLCH.SV.W.0002.110131T0119Z-110131T0215Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LAKE CHARLES LA
719 PM CST SUN JAN 30 2011

THE NATIONAL WEATHER SERVICE IN LAKE CHARLES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
SOUTHWESTERN HARDIN COUNTY IN SOUTHEAST TEXAS...
THIS INCLUDES...THICKET...SARATOGA...

* UNTIL 815 PM CST

* AT 719 PM CST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
SEVERE THUNDERSTORM...CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH...8 MILES NORTHWEST OF
THICKET...MOVING SOUTHEAST AT 15 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
VOTAW BY 730 PM CST...
THICKET BY 750 PM CST...
SARATOGA AND BATSON BY 815 PM CST...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS IN EXCESS OF 60 MPH...
DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND HEAVY RAIN. STAY INDOORS...
AWAY FROM WINDOWS.

&&

PLEASE REPORT SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE AT
337-477-5285 EXTENSION 1.

LAT...LON 3050 9472 3050 9467 3023 9446 3011 9461
3016 9464 3048 9474
TIME...MOT...LOC 0119Z 316DEG 12KT 3045 9473

$$

27

[vbhoutex]

I see Jeff on the site right now. Here is his latest take on this week.

A wild week is in store for the area....with multipe weather concerns.

Major arctic air outbreak will arrive Tuesday with a very cold air mass...temperatures will be the coldest of the winter season so far.

Models now in fair agreement on a potential winter storm event for coastal TX Thursday and Friday.

Arctic Outbreak:
Powerful arctic cold front is roaring down the plains this evening with 1050mb arctic high building over Canada NW of Montana ridging into the central plains. Strong arctic boundary will arrive into SE TX early Tuesday morning and push off the coast by mid afternoon. After highs in the 70's on Monday...it is downhill fast from that point as a bitter cold air mass invades from the north. Expect temperatures to fall from the 60's Tuesday morning into the 30's by mid afternoon with the freezing line reaching I-10 by early evening. Numerous showers and thunderstorms along the frontal boundary will end by early afternoon prior to the onset of freezing temperatures. Some residual moisture on overpasses could freeze by mid evening mainly N of HWY 105 as temperatures fall into the upper 20's. Very strong NW winds of 15-25mph will drive wind chills into the low teens and single digits across the region by Wednesday morning. Latest guidance shows little warming on Wednesday or Thursday and some lcoations may not reach freezing.

Large arctic dome locks in place across the state Wed-Sat with very cold air mass slow to modify. Expect hard freezes each night and daytime temperatures to struggle to only reach the mid to upper 30's if that.

Winter Storm Potential:
As hinted at a few times over the past few days has been the threat for energy to hang back to the SW of TX and attempt to eject moisture into the arctic air mass. Models had trended toward a much drier post frontal air mass, until the last two runs 00Z last night and 12Z this morning. Both the GFS and ECMWF have come in much wetter as an upper low develops in the base of the mean trough and ejects toward SW TX Thursday night/Friday. Models now prog isentropic lift over the cold air mass with widespread development of precipitation. Cold arctic air mass will be deeply entrenched across the entire state with the vertical column below freezing from the surface upward. Will go with P-type of mainly SN (snow) although some locations could see IP (sleet) for all locations including the coastal locations, the coastal bend, and parts of S TX.

Way too soon to start talking any kind of accumulations as there are some questions as to moisture amounts, but you do not need a lot of moisture to produce snow. If current model runs were to pan out, we could be looking at some pretty decent totals with little melting on the frozen ground from hours below freezing prior to the onset of the event.

As an aside the upper air pattern looks similar to the historic Christmas Eve snowstorm of 2004, but with a colder air mass and more entrenched arctic high. This fact alone gives me some concern as to question the potential amounts of moisture avialable as this air mass may be too cold to support much moisture.

Preparations:
Residents across the region should use Monday to prepare for an extended period of very cold temperatures. Tropical vegetation should be covered and protected along with exposed outside pipes and sprinkler systems. Given an extended period of wind chills in the teens and single digits preparations for exposed livestock should be made.

Toward the end of the week the threat could transition toward significant travel impacts should a winter storm event verify.

Jeff, if you see this post would/could you put a percentage on the chances for this storm to verify?

[southerngale]

hmmm, I think that's SNOW in the forecast. Meanwhile, got a doozy of a storm about to hit here!

[BigB0882]

Just wish it were higher than 10-20% Maybe it will increase as we get closer!

[LaBreeze]

Any idea on the chances of wintery precip making its way into SW LA and down to the coast?

[southerngale]

Just wish it were higher than 10-20% Maybe it will increase as we get closer!

Me too, but it's a start! Hopefully, the trends will increase our chances and not take them away.

Edit: Holy Moly - it is POURING! I mean, it is LOUD.

Special Weather Statement

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LAKE CHARLES LA
846 PM CST SUN JAN 30 2011

TXZ201-215-216-310330-
HARDIN TX-JEFFERSON TX-ORANGE TX-
846 PM CST SUN JAN 30 2011

...SIGNIFICANT WEATHER ADVISORY FOR HARDIN...JEFFERSON AND ORANGE
COUNTIES UNTIL 930 PM CST...

AT 843 PM CST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
STRONG THUNDERSTORM 6 MILES NORTHWEST OF BEVIL OAKS...MOVING
SOUTHEAST AT 15 MPH.

* THE STRONG THUNDERSTORM WILL BE NEAR...
BEVIL OAKS BY 905 PM...
BEAUMONT BY 930 PM...

THE PRIMARY THREATS FROM THIS STORM ARE PEA SIZE HAIL AND WIND GUSTS
TO NEAR 40 MPH...WHICH COULD DOWN TREE LIMBS AND BLOW AROUND
UNSECURED SMALL OBJECTS. SEEK SHELTER IN A SAFE HOME OR BUILDING
UNTIL THIS STORM HAS PASSED.


LAT...LON 3013 9407 2992 9416 3010 9440 3019 9421

[PTrackerLA]

This would be a really close call for my area. That would be light snow falling over SE Texas though! If the temperatures will be colder than the models are showing due to the snowpack to be put down to our north than things could get really interesting.

00z GFS - Friday morning:

[srainhoutx]

A week of Severe Weather, followed by an Arctic Outbreak, followed by snow ahead for SE TX/SW LA? Nuts...so much for boring weather around here...

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
508 AM CST MON JAN 31 2011

TXZ163-164-176>179-195>200-210>214-226-227-235>238-312215-
HOUSTON-TRINITY-MADISON-WALKER-SAN JACINTO-POLK-BURLESON-BRAZOS-
WASHINGTON-GRIMES-MONTGOMERY-LIBERTY-COLORADO-AUSTIN-WALLER-
HARRIS-CHAMBERS-WHARTON-FORT BEND-JACKSON-MATAGORDA-BRAZORIA-
GALVESTON-
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...WINNIE...MONT BELVIEU...ANAHUAC...EL CAMPO...WHARTON...
PIERCE...SUGAR LAND...MISSOURI CITY...RICHMOND...ROSENBERG...
EDNA...BAY CITY...PALACIOS...PEARLAND...LAKE JACKSON...ALVIN...
ANGLETON...FREEPORT...LEAGUE CITY...TEXAS CITY...FRIENDSWOOD...
GALVESTON
508 AM CST MON JAN 31 2011

...ARCTIC COLD FRONT TO ARRIVE TUESDAY WITH WINTRY PRECIPITATION
POSSIBLE FRIDAY...


AN ARCTIC COLD FRONT IS EXPECTED TO PUSH THROUGH SOUTHEAST TEXAS
DURING THE DAY TUESDAY. A LINE OF STRONG TO SEVERE THUNDERSTORMS
WILL DEVELOP ALONG IT TUESDAY MORNING WITH SOME STORMS PRODUCING
DAMAGING STRAIGHT LINE WINDS. STRONG NORTHERLY WINDS WILL BE
EXPECTED BEHIND THE FRONT AND A WIND ADVISORY MAY BE NEEDED FOR
MUCH OF THE AREA. THIS WILL USHER A MUCH COLDER AIRMASS INTO THE
AREA WITH TEMPERATURES FALLING INTO THE 40S BY TUESDAY AFTERNOON.
MINIMUM TEMPERATURES BY WEDNESDAY MORNING WILL BE IN THE LOW TO
MID 20S INLAND...UPPER 20S TO NEAR 30 ALONG THE COAST. A HARD
FREEZE WARNING MAY BE NEEDED. FREEZING TEMPERATURES WILL BE
POSSIBLE EACH NIGHT THROUGH THE END OF THE WEEK. RESIDENTS OF
SOUTHEAST TEXAS NEED TO MAKE NECESSARY PREPARATIONS TO PROTECT
PROPERTY AND LIFE FROM THE FREEZING TEMPERATURES. PIPES NEED TO
BE PROTECTED TO PREVENT BURSTING. PLANTS AND TENDER VEGETATION
WILL NEED PROTECTION FROM THE HARSH COLD. ENSURE THAT ELDERLY
PEOPLE AND CHILDREN ARE ALSO WELL PROTECTED AND HAVE SHELTER FROM
THE COLD CONDITIONS.

NWS METEOROLOGISTS WILL ALSO CONTINUE TO MONITOR A POSSIBLE
WINTER PRECIPITATION EVENT THURSDAY NIGHT THROUGH FRIDAY NIGHT.
THERE IS STILL LARGE UNCERTAINTY WITH REGARD TO THE TIMING OF THE
EVENT. AN UPPER LEVEL DISTURBANCE IS EXPECTED TO MOVE ACROSS THE
REGION EARLY FRIDAY MORNING THROUGH THE DAY TIME HOURS.
TEMPERATURES FRIDAY MORNING WILL BE WELL BELOW FREEZING SO SNOW
WILL BE THE MAIN PRECIPITATION TYPE. THE FROZEN PRECIPITATION
TYPE LARGELY DEPENDS ON MOISTURE AND TEMPERATURE PROFILES IN THE
LOWEST LEVELS OF THE ATMOSPHERE. THERE IS STILL SOME UNCERTAINTY
AS TO WHETHER THESE PARAMETERS WILL BE MET. RESIDENTS OF
SOUTHEAST TEXAS ARE ENCOURAGED TO CONTINUE TO MONITOR FORECASTS
FOR ANY CHANGES AND FOR UPDATED INFORMATION ON POSSIBLE HAZARDS
FROM ANY FROZEN PRECIPITATION.

[Jagno]

Our weather service is being ever so bold with this system that they don't even include a remote chance of snow in the visual forecast but they include this little snipet in the discussion,

WILL NEED TO MONITOR A SLIGHT CHANCE OF RAIN ON TUESDAY.
TEMPERATURES ALOFT ARE SUFFICIENTLY COLD THAT WINTRY PRECIP CANNOT
BE RULED OUT AT THIS TIME.

*edited by sg to fix quote tags

[southerngale]

Yeah, Jagno. I woke up and read the Houston NWS AFD, which was a great discussion BTW, and fought sleep for a while waiting on the LCH update. I was sorely disappointed.


Greg Bostwick from KFDM gave this little update this morning:

Only a few sprinkles today with highs in the upper 60's. Arctic cold front arrives around noon Tuesday with widespread rain and a few thunderstorms. Much colder by Wednesday morning with lows in the upper 20's. Highs Wednesday only in the upper 30's. Some sleet mixed with snow possible Friday.

[vbhoutex]

Here is the morning email from Jeff.

Dangerous winter weather heading for the state of Texas.

Preparations for an extended period of very cold air should be completed today.

Major winter storm to affect W and N TX tonight and Tuesday into the central plains

Winter precipitation possible across the entire TX coast (including S TX) Thursday and Friday.

Discussion:

Long advertised arctic outbreak is on the move this morning with the very cold air mass now crossing the US border over Montana and North Dakota. Current temperatures are -27 in northern Montana with the leading edge of the arctic front in central Wyoming. Strong blocking along the US west coast with ridging building deep into Alaska will force the -30 to -40 degree air mass over NW Canada southward into the US central plains over the next 24-36 hours. Appears record cold temperatures are on the way to much of the plains along with a major blizzard for the central plains and Great Lakes. Overnight lows forecast to drop into the -5 to -10 range over the Texas panhandle and possibly the lower teens to single digits over N TX. Sub-zero wind chills will be likely as far south as Waco by Wednesday.

Will break the impacts down by time periods to try and help layout an extremely difficult and changeable forecast.

Tuesday:

Powerful arctic boundary will reach the TX panhandle this evening and sweep southward across N TX by sunrise. Shallow but very cold air mass will undercut the warm Gulf surface layer with widespread rainfall/thunderstorms. Temperatures prior to the front will reach the mid-upper 60’s and then fall rapidly into the 30’s behind the front. Rain will change to freezing rain/sleet/snow from NW to SE over N TX during the day on Tuesday while a large blizzard develops from W TX into OK. Travel to W TX and N TX/OK on Tuesday will be extremely dangerous with heavy blowing snow on 40-45mph winds and temperatures in the teens and 20’s.

Tuesday night:

Arctic cold front blasts into the Gulf of Mexico with very strong cold air advection in progress. Winds will howl post front 20-35mph with gust to 40mph driving wind chills into the teens all across coastal Texas and to near zero as far south as Waco. Freezing line will advance to the US 59 corridor by mid evening and then to the coast with mid 20’s for all locations north of a line from Huntsville to Sugar Land to Victoria by Wednesday morning. This will be a damaging advective freeze for sensitive vegetation. Wind advisories may be required for parts of the area.

Wednesday:

Arctic dome deepens toward 900mb with low level moisture likely trapped near the surface keeping skies mostly cloudy. Strong north winds will continue to drive very cold air southward off the snow pack over W and N TX/OK. Will likely see very little warming to maybe freezing NW of a line from Conroe to Hempstead to Victoria. SE of this line highs may reach the mid 30’s. Wind chills will be in the teens. Clouds may clear out some Wednesday night allowing lows for Thursday morning to bottom out in the teens N of HWY 105, low 20’s along the US 59 corridor, and upper 20’s/low 30’s along the coast.

Forecast for Thursday onward is subject to major changes due to high uncertainty when dealing with forecasting winter precipitation in coastal Texas. There will be significant changes over the next few days to what is described below, it is the best prediction at this time with the model data available.

Thursday:

Upper level energy over the northern Rockies currently dives SSW into the SW US and then begins to move eastward toward TX. Arctic dome deepens toward 850-700mb (5,000-20,000 ft deep) with the center of the arctic high over western OK/KS. GFS is the fastest with this trough ejecting over TX while the ECMWF and CMC are the slowest. The CMC is by far the wettest with the GFS and ECMWF drier. Expect weak isentropic lift to begin midday Thursday thickening the mid level cloud deck. Soundings for CRP and VCT by Thursday evening show a saturated mid to low level profile completely below freezing, but all sounding sites show a very dry sub-cloud layer near the surface. Expect lifting processes and frontogenic forcing to develop meso scale banding of precipitation by Thursday afternoon/evening. Initial precipitation will likely evaporate before reaching the ground helping to moisten the near surface layer. Then once the dry layer is removed, precipitation will start to reach the ground. With the point forecast soundings showing a sub-freezing layer through the entire column for nearly all sites by Thursday afternoon/evening P-type will be snow, except maybe a period of IP (sleet) right along the coast. Expect highs near freezing along and N of I-10 and in the mid 30’s south of I-10

Thursday night:

Upper level trough moves toward/across Texas depending on which model you follow (GFS is the fastest with the ECMWF the slower and the GFS ensembles nearly splitting the difference). The faster GFS produces a quick shot of snow while the slower ECMWF and CMC would produce impressive snowfall totals across all of coastal Texas. Slower solution would allow greater time for the air mass to moisten and a longer period of meso scale snow banding to develop with higher snowfall rates. Surface layer will be in the mid to upper 20’s so what falls will accumulate and after days of sub-freezing temperatures the ground is going to be very cold. GFS shows best snowfall accumulation along a line from Victoria to W of Corpus Christi to McAllen on the order of 2-4 inches in this area. Still too early to be certain on any kind of accumulations as there are questions with moisture quality and how far inland the deeper moisture penetrates. This potential event has similarities to both the Dec 04 snowstorm and the snow event in Dec 1989 with the position of the upper and surface features. I am a little concerned about the amount of moisture available (usually it is the other way around, we do not have the cold air), but the models have been trending wetter with more QPF with each run adding confidence that something will fall later this week.

Friday:

Winter weather event will likely be ongoing Thursday night-Friday with potential for snow and some accumulations. Will go well below GFS guidance on highs and keep temperatures at or below freezing given falling precipitation, clouds, and possible snow accumulations for all areas including the coastal areas. Precipitation should gradually end from west to east Friday as the upper level trough moves over E TX and into LA allowing lift to decrease. Should the slower ECMWF and CMC models verify the best chances for snow will be on Friday and Friday night.

Preparations:

Residents across Texas should take the last warm day today to make the needed preparations for an extended period of cold weather. Protect/shelter sensitive tropical vegetation, hours of sub-freezing temperatures will damage or kill unprotected sensitive plants. Advective nature of the freeze with strong north winds will reduce the “greenhouse effect” of wrapping plants, so make sure coverings are strongly fastened with multiple layers.

Wrap exposed outside pipes and disconnect all water hoses from exterior wall connects. Turn off sprinkler systems and cover back flow preventer pipes which suffered greatly in the freeze last January. It might be a good idea to shut off the water supply to the entire sprinkler system to prevent freezing and bursting of the back flow pipes. Interior pipes should be fine with this event, but to be on the safe side open exterior facing cabinets to allow house warmth against the interior plumbing.

Pets and livestock should be sheltered is possible. Hours of sub-freezing temperatures and wind chills ranging from the single digits to teens will produce highly uncomfortable conditions for animals exposed for long periods of time.

Travel:

Dangerous/life threatening conditions will be developing over portions of W TX into the central plains tonight/Tuesday with full scale blizzard conditions as far south as southern OK. Surface travel is strongly discouraged in this region as significant snowfall and strong north winds of 30-40mph will blow and drift snow likely closing interstates and stranding vehicles. Temperatures over parts of OK and the TX panhandle will fall below zero with wind chills as low as -35 degrees making exposure to the outside air extremely dangerous. Aviation travel will likely be heavily impacted on Tuesday as major airports across the Midwest and plains struggle against heavy snow, low visibilities, and very cold air. Both Chicago and DFW will likely have major weather impacts/delays which will ripple into the rest of the system.

[southerngale]

Jeff's update... wow.