January-Foggy Mornings/Cool & Cloudy To The Month

[Ptarmigan]

18Z GFS is 'sniffing' some freezing rain and possibly some sleet very close to Metro Houston...

I suspect it will be further south in the coming hours and days.........

[Paul Robison]

18Z GFS is 'sniffing' some freezing rain and possibly some sleet very close to Metro Houston...

01062015 18Z GFS 90 gfs_mslp_pcpn_frzn_us_15.png

01062015 18Z GFS 96 gfs_mslp_pcpn_frzn_us_16.png

01062015 18Z GFS 102 gfs_mslp_pcpn_frzn_us_17.png

Will Houston experience the same kind of devastating ice storm that Atlanta, Georgia did back in February 2014 if (when) this freezing rain or sleet falls? Or is this a different weather regimen from the one that caused that storm? Would feel better if explained to me.

[tx_kingwood32]

Doubtful

[Paul Robison]

Doubtful

Then, we're looking at just a brief period of freezing rain or sleet in the Houston metro, if at all, as opposed to, say, the 1997 event, or last March's ice storm. No major infrastructural damage should be expected. Correct?

[skidog40]

If this arctic air arrives in Houston I'm not buying in on mid 30 temps. mid 30's is a outer edge with this front. If this thing comes through to the coast then I think forecast will change.

[brooksgarner]

That's a good 6hrs of freezing rain or sleet! While 18z gfs is the "bad run", maybe it's a sign of shifting model opinions... It makes sense though: dry dew points pulled in as that coastal low forms, producing dynamic cooling. If highs were already going to be in the upper-30s, as dew points around 28º-30º are pulled into the rain, temps could drop to near freezing. Why not? 'Tis the season.

[Karen]

What time will front clear the Houston area tomorrow

[ticka1]

what timeframe will the temps start plummenting tomorrow?

[Paul Robison]

That's a good 6hrs of freezing rain or sleet! While 18z gfs is the "bad run", maybe it's a sign of shifting model opinions... It makes sense though: dry dew points pulled in as that coastal low forms, producing dynamic cooling. If highs were already going to be in the upper-30s, as dew points around 28º-30º are pulled into the rain, temps could drop to near freezing. Why not? 'Tis the season.

Do you personally see this causing damage in the Houston metro similar to what happened during the February Atlanta storm which crippled that t city for a few days, Brooks? A significant icing event, in other words.

[srainhoutx]

The front will race S during the day tomorrow. The 00Z NAM suggests by the afternoon we will feel the gusty NW winds and chilly temperatures. Interesting the NAM also suggest a bit of wintry mischief with the secondary surge of cold air on Thursday night into Friday.

[brooksgarner]

Not at this time, Paul -- but I could picture some issues north of Houston. Most likely Lufkin to Waco... maybe down into Conroe. Still too soon to say. We honestly won't know until a day or so out -- and even then not for sure until the event begins and we observe temps falling as the rain cools temps to the dew point. So many if's. Pavement temps are still pretty warm, so icing would be relegated to branches and maybe bridges and overpasses.

[don]

0z GFS is just as cold as the 18z run

[brooksgarner]

0z GFS is just as cold as the 18z run

00z gfs shows much less icing near Houston than the 18z did. But we're all talking about the difference between 1 or 2 degrees. Certainly we need to watch!!

Good night.

[Katdaddy]

The Arctic front will arrive this afternoon:
URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
358 AM CST WED JAN 7 2015

...HARD FREEZE WARNING IN EFFECT FOR LATE WEDNESDAY NIGHT THROUGH
THURSDAY MORNING...
...WIND ADVISORIES ARE IN EFFECT FOR WEDNESDAY AFTERNOON AND
EVENING...

.AN ARCTIC FRONT MOVING ACROSS THE AREA TODAY WILL BRING STRONG
NORTHERLY WINDS AND MUCH COLDER TEMPERATURES. AS THE ARCTIC
AIRMASS SETTLES ACROSS THE AREA TONIGHT... IT WILL BRING THE
COLDEST TEMPERATURES OF THE SEASON. LOW TEMPERATURES IN THE UPPER
TEENS TO LOWER 20S ARE LIKELY ALONG AND NORTH OF A LINE FROM
BRENHAM TO LIVINGSTON. THESE TEMPERATURES ARE EXPECTED TO WARM
ABOVE 25 DEGREES BY MID MORNING THURSDAY.

TXZ210>213-226-227-235-072100-
/O.NEW.KHGX.WI.Y.0001.150107T1800Z-150108T0000Z/
AUSTIN-COLORADO-FORT BEND-HARRIS-JACKSON-WALLER-WHARTON-
INCLUDING THE CITIES OF...BELLVILLE...BROOKSHIRE...COLUMBUS...
EAGLE LAKE...EDNA...EL CAMPO...HEMPSTEAD...HOUSTON...HUMBLE...
KATY...MISSOURI CITY...PASADENA...PIERCE...PRAIRIE VIEW...
RICHMOND...ROSENBERG...SEALY...SUGAR LAND...TOMBALL...WEIMAR...
WHARTON
358 AM CST WED JAN 7 2015

...WIND ADVISORY IN EFFECT FROM NOON TODAY TO 6 PM CST THIS
EVENING...

THE NATIONAL WEATHER SERVICE IN HOUSTON/GALVESTON HAS ISSUED A
WIND ADVISORY...WHICH IS IN EFFECT FROM NOON TODAY TO 6 PM CST
THIS EVENING.

* EVENT...NORTH WINDS 20-30 MPH THIS AFTERNOON AND A HARD FREEZE
FOR SEVERAL HOURS OF TEMPERATURES AT OR BELOW 24 DEGREES TONIGHT.

* TIMING...THIS AFTERNOON.

* IMPACT...SECURE LOOSE OUTDOOR ITEMS...LIKE LAWN CHAIRS OR YARD
DECORATIONS. THERE IS ALSO THE POTENTIAL FOR EXPOSED PIPES TO
FREEZE AND SENSITIVE VEGETATION TO BE DAMAGED.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DRIVERS OF VANS...CAMPERS...TRAILERS...AND OTHER HIGH-PROFILE
VEHICLES SHOULD BE ALERT TO THE DANGER OF THESE WINDS...
ESPECIALLY WHEN DRIVING ALONG EAST TO WEST ORIENTED ROADS

[ticka1]

Where is the front located now?

I think the surface temps are too warm to be a major icing issue - but time will tell what happens.

[Portastorm]

Winter weather looking more and more likely for south central Texas:


000
WWUS84 KEWX 071019
SPSEWX

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
419 AM CST WED JAN 7 2015

TXZ171>173-183>194-202>209-217>225-228-072300-
LLANO-BURNET-WILLIAMSON-VAL VERDE-EDWARDS-REAL-KERR-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...DEL RIO...
ROCKSPRINGS...LEAKEY...KERRVILLE...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
419 AM CST WED JAN 7 2015

...WINTER WEATHER OUTLOOK FOR FRIDAY NIGHT THROUGH SATURDAY
MORNING...

TWO SURGES OF ARCTIC AIRMASSES WILL BRING MUCH COLDER WEATHER TO
SOUTH CENTRAL TEXAS BEGINNING TODAY. AN UPPER LEVEL DISTURBANCE
WILL APPROACH THE AREA FRIDAY NIGHT AND WILL BRING WITH IT A
CHANCE OF PRECIPITATION TO THE REGION. AS OF TODAY...THE
FORECASTED LOCATION OF THE FREEZING LINE SATURDAY MORNING IS
EXPECTED TO BE NEAR A LANGTRY TO UVALDE TO FLORESVILLE TO
GIDDINGS LINE. AREAS NORTH OF THIS LINE ARE FORECASTED TO BE
BELOW FREEZING FRIDAY NIGHT/SATURDAY MORNING AND A MIXTURE OF
FREEZING RAIN AND SLEET IS POSSIBLE. THIS AREA INCLUDES THE
AUSTIN AND SAN ANTONIO METRO AREAS. THE COLDEST TEMPERATURES WILL
BE IN THE HILL COUNTRY AND THIS IS WHERE MOST IMPACTS ARE
EXPECTED. DEPENDING ON HOW MUCH PRECIPITATION FALLS...THERE COULD
BE ICING CONDITIONS ON ROADWAYS WHICH WOULD LEAD TO HAZARDOUS
DRIVING CONDITIONS. THE FORECAST WILL CONTINUE TO BE REFINED OVER
THE NEXT 48 TO 72 HOURS AND RESIDENTS SHOULD KEEP UP TO DATE FOR
ANY POSSIBLE FORECAST CHANGES.

$$

HAMPSHIRE

[srainhoutx]

Where is the front located now?

The wind shift has passed College Station, but the colder air is lagging behind back up into N Texas. The strongest barometric pressure I could find this morning was near Rapid City, SD with a 1054mb reading. Lots of light snow and negative temperatures across the Northern Plains and the Northern Rockies this morning. Still some -36F readings in Eastern Alaska and some -40C readings in the NW Territories of Canada.

[nuby3]

I am running Bandera 100K on Saturday. Looking awesome for it!!!

[srainhoutx]

Here is the 03Z SREF ensemble precipitation types valid for Saturday...

[srainhoutx]

Morning briefing from Jeff:

Strong arctic cold front will arrive this morning.

Hard Freeze Warning is in effect for tonight for area north of HWY 105

Wind Advisory in effect all counties this afternoon

Gale Warning in effect all coastal and offshore waters today and tonight

Freezing rain and sleet possible north of a line from Columbus to Livingston Friday night/Saturday.

Discussion:
Massive 1055mb arctic high crashing through the plains with leading edge of the arctic front approaching the northern counties of SE TX. Dense cold air mass is lagging the wind shift by about 3-4 hours and the onset of strong cold air advection and falling temperatures will be midday across SE TX. Very strong winds of 25-35mph with gust to 40mph will onset with the cold air advection especially along and west of I-45 and across the coastal counties. Cold air advection will drive the freezing line southward this afternoon and into SE TX this evening and across nearly all of the area by Thursday morning. Still looking at some mid and high level clouds and gusty winds overnight to help prevent the bottom from falling out of the temperatures…but a widespread freeze is nearly certain at this point. Winds in the 10-15mph range overnight will lower wind chill values into the 10’s across much of the area Thursday morning.

Main forecast concerns this morning as how cold tonight and then how cold this weekend with a secondary surge of arctic air and P-type across the region.

Low Temperatures Thursday Morning:

North of HWY 105: 19-25

North of US 59: 26-30

Inside Beltway 8: 29-32

N of HWY 35: 29-32

Beaches: 32-35

Area north of Hwy 105 will likely experience sub freezing conditions for 8-14 hours with hard freeze conditions of 25 or below for up to 2-6 hours. North of US 59 will likely see freezing temperatures of 6-8 hours.

Precautions for sub-freezing temperatures should be rushed to completion today.

Friday-Saturday:
Weak short wave will cross the area Friday morning with sub freezing temperatures in place. Feel the low level air mass will be very dry and little if any precipitation will reach the ground. If it does it would likely be in the College Station to Livingston area and fall as sleet or sleet/freezing rain mix. Think this is overall a very low threat.

Bigger concern is taking shape for Friday night into Saturday as a stronger short wave and secondary arctic surge moves across the region.

Will have to go ahead and introduce freezing/frozen precipitation into the area for Friday night and Saturday morning. Latest guidance has been trending colder and colder with incoming secondary arctic surge Friday afternoon and now has at least the northern ½ of the area subject to freezing temperatures overnight Friday into Saturday morning. GFS is most aggressive in pushing the surface freezing line to I-10 and even south of that to the west of Houston supporting freezing rain very far south. Other models including the NAM are warmer by a degree or two and keep the precipitation liquid over Harris County.

I am becoming concerned that the models may be under-estimating the incoming cold air slightly since the trend since yesterday has been for colder and colder. Additionally very low dewpoints (25-30) suggest a bit of room for evaporational cooling of the air column to near freezing or below even if guidance temperatures suggest above freezing.

As for P-types warm nose in the mid levels supports a freezing rain sounding with a shallow freezing layer near the surface. Warm air advection processes will attempt to erode this surface freezing layer…but it is going to be hard to do. Could see some sleet mixed with the onset of the precipitation Friday night, but the overall profile is a freezing rain one.

For now will go with freezing rain and sleet mix Friday night into Saturday morning north of a line from Columbus to Conroe to Livingston with some ice accumulation expected on elevated surfaces. Bridges and overpasses will be “very cold” from the hard freeze tonight in this area so ice accumulation on these surface is certainly possible.

Will keep all precipitation south of the Columbus to Livingston line liquid for now, but any additional cooling trends in the model guidance will require the freezing rain line to be adjusted southward close to metro Houston and the I-10 corridor.

Forecasted QPF amounts are concerning especially when dealing with freezing rain as 1-2 inches of liquid are expected over the region from late Friday-Monday. Critical period of Friday night/Saturday morning suggest at least .25-.50 of an inch of liquid QPF across the region and some of this will be in the form of ice across the northern counties. Would like to be more certain on surface temperatures before trying to hammer out ice accumulations.

Not sure temperatures will warm much if at all on Saturday and this could linger freezing rain and ice potential into Saturday night and Sunday allowing greater accumulation amounts across those northern areas.

As with all winter weather events in this area there is a large amount of uncertainty and the difference of 1-2 degrees will make the difference between an ice storm and all rain.