Texas winter wx thread (2009-2010)

[southerngale]

Very interesting discussion from LCH for SE TX/SW LA. They're giving me hope that I'm sure will be crushed later. lol

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
412 PM CST WED FEB 10 2010

.DISCUSSION...
SFC ANALYSIS SHOWS HIGH PRESSURE CENTERED OVER ERN KS AND OK/NERN
TX PROVIDING FOR A MAINLY LIGHT NERLY FLOW OVER THE FORECAST AREA.
MEANWHILE AN INVERTED TROF IS DEPICTED UP THE LOWER/MID TX COAST.
WATER VAPOR IMAGERY SHOWS A ZONAL FLOW ALOFT WITH PLENTIFUL PACIFIC
MOISTURE NOW STREAMING OVER THE AREA...AND SATELLITE PIX SHOW THE
EXPECTED THICK CIRRUS SHIELD NOW OVERHEAD. REGIONAL 88DS SHOW AN
AREA OF LIGHT PRECIP ALONG THE MIDDLE TX COAST AND UP INTO CNTL
TX. SFC OBS ARE GRADUALLY SHOWING MORE AND MORE RAINFALL WITH THIS
ACTIVITY AS LOWER ATMOSPHERE GRADUALLY MOISTENS.

NOT MUCH TO ADD TO EARLIER THINKING REGARDING UPCOMING RAIN/WINTER
WX EVENT. THE RAINFALL TO OUR WEST SHOULD CONTINUE MOVING EWD
TOWARD THE AREA WHILE ALSO MOISTENING THE AIRMASS. EXPECT LIGHT
RAIN TO DEVELOP OVER THE WRN ZONES AFTER SUNSET THEN GRADUALLY
SPREAD EWD THROUGH THE NIGHT. FORECAST SOUNDINGS THIS EVENING SHOW
THE LOWER ATMOSPHERE STAYING JUST ABOVE FREEZING BUT EVAPORATIVE
COOLING SHOULD ALLOW SOME SLEET TO DEVELOP MAINLY OVER THE NRN 1/2
OF THE AREA. TOWARD SUNRISE AS TEMPS COOL TO AROUND FREEZING OVER
THIS SAME REGION WOULD EXPECT SOME FLURRIES TO BEGIN DEVELOPING.
LITTLE TO NO ACCUMULATION EXPECTED OVERNIGHT.

THE SFC LOW IS PROGGED TO DEVELOP OFF THE LOWER TX COAST TOMORROW.
MEANWHILE STRONG MID-LEVEL SHORTWAVE AND RRQ OF H2 JET MAX WILL
MOVE INTO THE REGION. ALL OF THIS WILL HELP PRODUCE AN INCREASE IN
RAINFALL COVERAGE AND INTENSITY WITH CATEGORICAL CHANCES OVER THE
ENTIRE AREA BY THE AFTERNOON. MODEL SOUNDINGS INDICATE A LIKELY
CHANGEOVER FROM RAIN TO SNOW OR POSSIBLY A MIX OVER THE NERN
ZONES WILL START BY LATE-AFTERNOON AS MOST OF THE LAYER ABOVE 800
OR SO FEET COOLS TO BELOW FREEZING. ABOVE-FREEZING SFC TEMPS
SHOULD PRECLUDE ACCUMULATIONS.

AS WE MOVE INTO THURSDAY NIGHT WILL LIKELY SEE A COMPLETE
CHANGEOVER TO SNOW OVER THE NRN 1/2 OF THE AREA ALTHOUGH WILL HOLD
ONTO A RAIN/SNOW MIX IN THE GRIDS/ZONES FOR NOW WITH LATER
FORECASTS ALLOWED TO BETTER REFINE THE PRECIP TYPE. ALSO AS SFC
TEMPS FALL CLOSER TO THE FREEZING MARK WE WILL BEGIN TO SEE
STICKING ON GRASS AND ELEVATED SURFACES. THIS WILL PERSIST INTO
FRIDAY MORNING BEFORE THE SHORTWAVE AND SFC LOW BOTH MOVE EAST OF
THE AREA AND PRECIP TAPERS OFF INTO THE AFTERNOON. IN ADDITION
SLIGHT GRADUAL WARMING SHOULD ALLOW ALTHOUGH A CHANGEOVER BACK TO
RAIN...ALTHOUGH THIS IS NOT A DEFINITE OVER THE EXTREME NERN ZONES
WHERE TEMPS MAY NOT GET OUT OF THE 30S. IT SHOULD ALSO BE NOTED
THAT FLURRIES ARE DEFINITELY POSSIBLE ALONG THE I-10 CORRIDOR...
ESPECIALLY EAST OF JENNINGS WHERE SLIGHTLY COOLER TEMPS THROUGH
THE COLUMN ARE SEEN IN FORECAST SOUNDINGS. HOWEVER ATTM HAVE
ELECTED TO KEEP ONLY RAIN MENTIONED FOR THESE AREAS.

HIGHEST ACCUMULATIONS ATTM LOOK TO BE OVER THE EXTREME NERN ZONES
WHERE UP TO 2 INCHES WILL BE POSSIBLE...THEN TREND DOWNWARD TO SAY
A 1/4 INCH NORTH OF THE I-10 CORRIDOR. FOR THIS REASON WILL BE
ISSUING A WINTER WEATHER ADVISORY FOR THURSDAY NIGHT AND FRIDAY
FOR THE NRN 1/2 OF THE AREA. IT SHOULD BE NOTED THAT SOME GUIDANCE
CALLS FOR AMOUNTS DEFINITELY HIGHER THAN 2 INCHES FOR THE EXTREME
NERN ZONES...AS WELL AS BRINGING WINTER PRECIP INTO THE SRN ZONES.
HAVE ELECTED TO GO THE CONSERVATIVE ROUTE FOR NOW AND ALLOW LATER
SHIFTS TO BETTER REFINE THE WINTER WEATHER THREAT AND THE POSSIBLE
NEED TO UPGRADE THE ADVISORY TO A WATCH OR WARNING.

BEYOND THIS EVENT...EXPECT DRY WEATHER FRIDAY NIGHT THROUGH
SATURDAY AS NWRLY FLOW TAKES OVER ALOFT AND SFC HIGH PRESSURE
PASSES THE AREA. CUTOFF LOW DROPPING THROUGH THE PLAINS IS PROGGED
TO PULL A COLD FRONT ACROSS THE AREA SUNDAY USHERING IN A BRIEF
PERIOD OF RAINFALL. DRY WEATHER SHOULD THEN PERSIST FOR THE
REMAINDER OF THE PERIOD.

[ColdFusion]

With a forecast high of 47 for friday, and no indication so far that there will be a major road icing event, i dont see why any school should be cancelled simply because a snow accumulation will occur.

[msstateguy83]

[natlib]

As usual, San Angelo is right on the edge of the snow/rain line. There is a Winter Weather Advisory 1 county to our north for 1 to 3 inches, but we're in the rain/snow or little accumulation area. Oh well...maybe next year.

[Weatherdude20]

With a forecast high of 47 for friday, and no indication so far that there will be a major road icing event, i dont see why any school should be cancelled simply because a snow accumulation will occur.

Sorry totally misread.

[Ntxw]

With a forecast high of 47 for friday, and no indication so far that there will be a major road icing event, i dont see why any school should be cancelled simply because a snow accumulation will occur.

upper 20s for Thurs night to Friday morning. It's not going to be 47 in the morning hours. With possible snow on the ground that number itself looks optimistic. I think at least there would be a 2 hour delay maybe.

[TornadoAlleyMom]

No crickets tonight, my invisible friends!!!!

I don't post often, but I sure do enjoy following you guys and your discussions!!!

Thank you for the knowledge and insight....

At this point, has any mention been made as to whether or not we're in any danger with this storm (i.e. accumulations on powerlines, etc.)?

[jeff]

Light sleet in Richmond now going on 2 hours....mixing with Rain at times.

[iorange55]

I'm glad to see things in our favor for once. Although NWS is still making me scared with this it could be all rain stuff. I've got my video camera ready, jacket. I do need gloves, though.

[Dustan78]

With a forecast high of 47 for friday, and no indication so far that there will be a major road icing event, i dont see why any school should be cancelled simply because a snow accumulation will occur.

And yesterday the forecast was for a snow/rain mix with less than an inch on grass. Just saying

[Ntxw]

I'm glad to see things in our favor for once. Although NWS is still making me scared with this it could be all rain stuff. I've got my video camera ready, jacket. I do need gloves, though.

NWS is giving you the full spectrum, from no snow (low too far south), to rain (warming layer), to snow (current forecast), to possibly heavy snow (possible winter storm warning if temps are colder), to finally a combo of all the above. That's what I call forecasting! Im surprised they haven't put the idea that we might get into a cloud clearing pocket for bright sunshine!

Edit: Something i've noticed not that it really matters from the past snow\ice events, FW doesn't seem to like putting up winter storm watches lol. Maybe they don't like the blue color.

[PineyWoods]

Light sleet here in Spring Branch also.

Wouldn't it be nice if you had a few snow events like in '73?

[iorange55]

I'm glad to see things in our favor for once. Although NWS is still making me scared with this it could be all rain stuff. I've got my video camera ready, jacket. I do need gloves, though.

NWS is giving you the full spectrum, from no snow (low too far south), to rain (warming layer), to snow (current forecast), to possibly heavy snow (possible winter storm warning if temps are colder), to finally a combo of all the above. That's what I call forecasting! Im surprised they haven't put the idea that we might get into a cloud clearing pocket for bright sunshine!

"forecasting"

[msstateguy83]

powerline issue was brought up... doubt that we see any sort of widespread probs with power outages.. it would take ALOT of snow to cause that, we will not be seeing much in the way of frz rain should be mostly all snow...

[WacoWx]

when does the next set of model data come out?

[msstateguy83]

around 7:30 this evening the 00z nam will be running

[vbhoutex]

Light sleet here in Spring Branch also.

Wouldn't it be nice if you had a few snow events like in '73?

Still not out of the question, but becoming less likely with each day.

[wxman57]

Here's the lower part of a vertical temperature profile (RUC 21Z) centered on southwest Houston to show what's happening aloft. For those who can't read the chart, it shows snow falling from a height of 18,000 to 6000ft up. Below 6000 ft there is a warm layer which melts the snowflakes (they're delicate). Below about 3000 ft the raindrops (melted snow) hit a sub-freezing layer for a couple thousand feet. This freezes the raindrops into ice (sleet). The sleet falls through about 1000-2000 ft of above-freezing air, surviving to hit the ground. They're small because much of the sleet is melting off on the way down.

Now currently there is only a thin layer of above freezing temperatures aloft, with the exception of the very lowest layer that reaches the mid 40s. There's a slim chance that if the airmass modifies slightly between 3000-6000 ft and drops closer to freezing that a few snowflakes may make it to the ground, though somewhat melted. I think I MAY have seen 1-2 of these on my drive home, as the spot on my windshield looked more like slushy snow than sleet at least once.

Don't get your hope up (even slightly) that you'll awaken tomorrow to a snow-covered landscape (Houston area). That airmass aloft should WARM overnight, reducing the chances for sleet or snow. It's cold rain for us tomorrow, but you still COULD see a trace of sleet tomorrow night.

Note: Heights on the chart are very approximate

[msstateguy83]

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org. For official information, please refer to NWS products.

[DentonGal]

Something FROZEN is falling from the sky here in Denton! Snow granules? Definitely not sleet and not flakes......