February: Tracking Rain/Wintry Mix & Arctic Front

[srainhoutx]

Light freezing drizzle reported in Wimberley (Hays County) in Central TX.

[srainhoutx]

Afternoon briefing from Jeff:

Light drizzle with occasional light rain falling across SE TX this afternoon.

Temperatures have been nearly steady in the low to mid 30’s from College Station to Livingston to upper 30’s along I-10 to lower 40’s along the coast. Temperatures have not moved much in the last 3-4 hours with the freeze line remaining from roughly Caldwell to Crockett and has shown very little southward movement since about 900am this morning.

Should see the freezing line begin to move southward late this afternoon and this evening reaching a Brenham to Conroe line by mid evening. Precipitation remains very light mostly in the form of drizzle with accumulations of less than .05 of an inch.

As temperatures fall to freezing north of a Columbus to Conroe to Cleveland line this evening wet roads and drizzle will likely begin to freeze on elevated surfaces including bridges and overpasses producing a thin glaze of ice.

South of Columbus to Conroe to Cleveland pockets of freezing temperatures will be possible after 1000pm, but precipitation should be gradually ending by this time. It is possible that a few wet bridges could have a few patches of ice across Waller, north Harris (Cypress to Spring to Kingwood) and southern Montgomery Counties especially if drizzle lingers a little longer than expected.

Decision Support Matrix:

Burleson, Houston, Madison, Walker, Trinity, San Jacinto, Polk:

Ice Accumulation: .03-.06 of an inch

Timing: 600pm Monday-600am Tuesday

Temperatures: 28-30 degrees

Winds: NNE 15-20mph

Confidence: high



Transportation: anti-ice operations in progress

Education: delays and cancellations possible

Aviation: anti-ice operations likely

Power: isolated outages possible

Brazos, Grimes, Washington, Montgomery, Waller, northern Liberty:

Ice Accumulation: .02-.04 of an inch

Timing: 600pm Monday-600am Tuesday

Temperatures: 30-32 degrees

Winds: NNE 10-15mph

Confidence: high



Transportation: anti-ice agent being deployed

Education: delays possible

Aviation: anti-ice operations likely

Power: isolated outages possible

Austin, Colorado, north Harris (Cypress-Spring-Kingwood), central Liberty:

Ice Accumulation: isolated ice accumulation possible

Timing: 1000pm Monday-600am Tuesday

Temperatures: 32-33 degrees

Winds: NNE 10-15mph

Confidence: moderate



Transportation: monitor trends/standby equipment and personnel…ice prevention operations in progress

Education: None

Aviation: anti-ice operations possible at Hooks and IAH

Power: None

Fort Bend, southern Harris, Wharton, Jackson, Matagorda, Brazoria, Galveston, Chambers:

Ice Accumulation: None expected at this time

Timing: N/A

Temperatures: 33-35 degrees

Winds: NNE 14-18mph

Confidence: moderate



Transportation: None

Education: None

Aviation: None

Power: None

[srainhoutx]

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE FORT WORTH TX
346 PM CST MON FEB 23 2015


HENDERSON-MILLS-HAMILTON-BOSQUE-HILL-NAVARRO-FREESTONE-ANDERSON-
LAMPASAS-CORYELL-BELL-MCLENNAN-FALLS-LIMESTONE-LEON-MILAM-
ROBERTSON-
INCLUDING THE CITIES OF...ATHENS...GUN BARREL CITY...
GOLDTHWAITE...HAMILTON...HICO...CLIFTON...MERIDIAN...
VALLEY MILLS...HILLSBORO...CORSICANA...TEAGUE...FAIRFIELD...
PALESTINE...LAMPASAS...COPPERAS COVE...GATESVILLE...KILLEEN...
TEMPLE...FORT HOOD...WACO...MARLIN...MEXIA...GROESBECK...
BUFFALO...CENTERVILLE...JEWETT...OAKWOOD...CAMERON...ROCKDALE...
HEARNE...FRANKLIN...CALVERT
346 PM CST MON FEB 23 2015

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 6 AM CST
TUESDAY...

* TIMING...NOW THROUGH 6 AM TUESDAY.

* PRECIPITATION TYPE...MAINLY LIGHT SLEET AND LIGHT FREEZING
RAIN.

* ACCUMULATIONS...ADDITIONAL SLEET ACCUMULATIONS UP TO 1/10 OF
AN INCH AND A FEW HUNDREDTHS OF AN INCH OF ICE ACCUMULATION
FROM FREEZING RAIN.

* TEMPERATURES...UPPER 20S TO NEAR 30 DEGREES.

* MAIN IMPACT...LIGHT SLEET AND ICE ACCUMULATIONS WILL CONTINUE
TO MAKE TRAVEL HAZARDOUS ON AREA BRIDGES AND OVERPASSES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY MEANS THAT PERIODS OF WINTER
PRECIPITATION MAY CAUSE TRAVEL DIFFICULTIES. BE PREPARED FOR
SLIPPERY ROADS AND PLAN ON SOME TRAVEL DELAYS.


GRAYSON-FANNIN-LAMAR-DENTON-COLLIN-HUNT-DELTA-HOPKINS-TARRANT-
DALLAS-ROCKWALL-KAUFMAN-VAN ZANDT-RAINS-JOHNSON-ELLIS-
INCLUDING THE CITIES OF...SHERMAN...DENISON...BONHAM...PARIS...
DENTON...LEWISVILLE...FLOWER MOUND...THE COLONY...PLANO...
GREENVILLE...COMMERCE...COOPER...SULPHUR SPRINGS...FORT WORTH...
ARLINGTON...DALLAS...ROCKWALL...TERRELL...KAUFMAN...FORNEY...
WILLS POINT...CANTON...GRAND SALINE...VAN...EDGEWOOD...EMORY...
POINT...EAST TAWAKONI...CLEBURNE...BURLESON...WAXAHACHIE...
ENNIS...MIDLOTHIAN...GLENN HEIGHTS
346 PM CST MON FEB 23 2015

...WINTER STORM WATCH IN EFFECT FROM LATE TUESDAY NIGHT THROUGH
WEDNESDAY MORNING...

THE NATIONAL WEATHER SERVICE IN FORT WORTH HAS ISSUED A WINTER
STORM WATCH...WHICH IS IN EFFECT FROM LATE TUESDAY NIGHT THROUGH
WEDNESDAY MORNING.

* TIMING...AFTER MIDNIGHT TUESDAY NIGHT THROUGH NOON WEDNESDAY.

* PRECIPITATION TYPE...SNOW.

* ACCUMULATIONS...1 TO 3 INCHES WITH LOCALLY HIGHER AMOUNTS
POSSIBLE.

* MAIN IMPACT...TRAVEL ON ALL ROADWAYS...BRIDGES AND OVERPASSES
MAY BE HAZARDOUS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT
SNOW...SLEET...OR ICE ACCUMULATIONS THAT MAY IMPACT TRAVEL.

[srainhoutx]

Heaviest light rain of the day across NW Harris County with a temperature drop to 35.7F. This passing light shower was far more than a drizzle.

[Paul Robison]

Heaviest light rain of the day across NW Harris County with a temperature drop to 35.7F. This passing light shower was far more than a drizzle.

General question for srainhoutx:

NWS will watch for a rain/sleet mix in Houston County on Wednesday. Does sleet glaze roads/elevated surfaces like ice does?
In other words: What is the difference between a rain/sleet mix and an ice storm?

P.S. What is your personal climate preference, srainhoutex? Hot or cold?

[BlueJay]

Down to 35F already. I hope we don't go below 33F, as David Paul has forecasted for our area. We will see.

Stay warm and safe everyone!

[Andrew]

00z sounding from kcll

[TxLady]

Snowing in Huntsville, as of a few minutes ago

[JulieC]

What does the sounding that was posted mean?

[jasons2k]

Moist at the surface with a very pronounced warm nose aloft. Virtually impossible for snow. I'd be curious to see where that report of "snow" from Huntsville came from. That sounding certainly does not support snow.

[TexasBreeze]

The NWS bought into the reports. Updated the discussion and added snow to the forecast.

[JulieC]

Impossible for snow.

Seems like this is turning into a non-event for the Katy area.

[Andrew]

Snow is possible in that profile if the origination of the precip was 900mb or lower. Small ice nuclei are possible with that sounding at -6C, just not common. Furthermore over hunstville that layer could be slightly deeper.

[Kludge]

Moist at the surface with a very pronounced warm nose aloft. Virtually impossible for snow. I'd be curious to see where that report of "snow" from Huntsville came from. That sounding certainly does not support snow.

I agree that the science would make it appear virtually impossible... but it was snow. Tiny flakes...not sleet, graupel, or freezing mist... flakes. Only lasted about 10 minutes. Likely a freakish occurrence.

And there was a small accumulation on the grill that was absolutely a powder... which I could easily blow off.

That said... I wanted frozen precip all winter, but not any longer. Bring on Spring!

[TxLady]

The snow report, that I posted about, came from friends (students) at SHSU. It is now "not" snowing in New Waverly. I'm trying to figure out how to post a couple of pics....

[jasons2k]

I'll eat my crow then. Yes, I have seen snow too from very low clouds, a few times along the escarpment in Lubbock. I didn't think we were having our precip from that low, but thinking through the drizzle scenario we are having, it would make sense.

Hey, I've witnessed sleet pellets before here a few years ago when it was almost 50 degrees at the surface and Wxman said the sounding showed it was impossible too, so I believe you

[TxLady]

I posted the pics to the "Houston Weather Board" on Facebook.

[Ptarmigan]

Impossible for snow.

Seems like this is turning into a non-event for the Katy area.

It is not over until it is over.

[wxman57]

Snowing in Huntsville, as of a few minutes ago

That appears to be what is called snow grains. Snow grains differs from snow in that it can form in stratus clouds not far above the surface (where it's below freezing in Huntsville). The crystals are small and elongated, less than 1mm in size. They aren't true snowflakes, which form higher up in the atmosphere.

[Heat Miser]

It is not over until it is over.

It's over, at least for the majority of the area. And, I'm not sure Katy was ever in an area that was threatened to begin with.