Texas Winter 2013-2014

[gboudx]

Some light returns are beginning to show up on the radar across Dallas-Fort Worth. Doubt any of it is reaching the ground at this point, but it'll be interesting to see how these returns evolve.

I've noticed the sky darkening here at the SE corner of 75/Bush. If it starts spitting outside, I'm telling the boss I'll continue my workday from the confines of home.

[TexasF6]

Abc Local met said cold drizzle all weekend!? Really?

[wxman57]

If I am reading that last meteogram right it looks like almost .10 for possible ice, that would be enough to drive this city crazy (pun intended for driving on ice). Correct me if I am wrong Portastorm or someone else.

Looks closer to .05" liquid falling with sub-freezing temps. Not enough to cause problems with power lines or trees, but enough for ice on bridges and overpasses - probably not surface streets. Of course, if the surface temp drops to 28-29 or lower then surface streets may have issues.

[cheezyWXguy]

that band of light precip on top of dfw might not be reaching the ground right now, but it is decreasing temps underneath it. Temp in in plano has decreased from 34.5 to 33.7 according to wunderground.

[orangeblood]

Update from DFW NWS

UPDATE...
STRONG COLD AIR ADVECTION BEHIND LAST NIGHT/S COLD FRONT WILL
NEGATE THE EFFECTS OF DIURNAL HEATING TODAY...ALLOWING
TEMPERATURES TO REMAIN NEAR CURRENT READINGS THROUGH THE AFTERNOON
HOURS. TEMPERATURES MAY IN FACT DROP A COUPLE OF DEGREES IN A FEW
SPOTS. RADAR INDICATES A BROAD SWATH OF LIGHT PRECIPITATION JUST
NORTHWEST OF THE BOWIE AND JACKSBORO AREAS. MUCH OF THIS MAY NOT
BE ACTUALLY REACHING THE GROUND...BUT WE EXPECT THIS AREA TO INTENSIFY
OVER THE NEXT FEW HOURS AS IT SHIFTS EAST INTO OUR NORTHWEST
COUNTIES. THE 18Z / NOON LOCAL ONSET OF THE WINTER STORM WARNING
OVER THE NORTHWESTERN PARTS OF NORTH TEXAS LOOKS PRETTY MUCH ON
TRACK AT THIS TIME.

PRECIPITATION WILL BEGIN TO AFFECT AREAS FARTHER EAST...INCLUDING
THE DALLAS-FORT WORTH METROPLEX...THIS EVENING THROUGH FRIDAY
MORNING. 12Z GUIDANCE CONTINUES TO SUPPORT TEMPERATURES FALLING
BELOW FREEZING IN THE REST OF THE WINTER STORM WARNING AREA AS
PRECIPITATION INCREASES LATE TONIGHT. WE WILL CONTINUE WITH THE 6
PM / 00Z START TIME OF THE WINTER STORM WARNING FOR THE METROPLEX
AND SURROUNDING COUNTIES...EVEN THOUGH THE MORE SIGNIFICANT
PRECIPITATION MAY HOLD OFF UNTIL THE 9 PM - 12 AM TIME FRAME. IT
STILL LOOKS LIKELY THAT A QUARTER TO A HALF INCH OF ICE IS A REAL
POSSIBILITY FOR A GOOD PORTION OF THE WARNED AREA...AND ISOLATED
HIGHER TOTALS CANNOT BE RULED OUT.

What I find odd about their ice accumulation amounts of 1/4 to 1/2 inch is that all of the major models show low end 3/4 inch QPF with the GFS showing 1.25 inches of QPF. Are they assuming 25-40% of this precip will melt upon contact ? Appears like there should be a wide area of greater than 1/2 inch ice accumulations

[dhweather]

From the FTW NWS via twitter

[Tejas89]

Temps starting to creep back up or at least stabilize at DFW for now.

If we can a big chunk of the precip. outta here before temps fall into the 20's late tonight (faster moving system?) maybe we'll have a "rooftop" event instead of a skating rink. Neither is good.. only a hope not a forecast.

[ndale]

If I am reading that last meteogram right it looks like almost .10 for possible ice, that would be enough to drive this city crazy (pun intended for driving on ice). Correct me if I am wrong Portastorm or someone else.

Looks closer to .05" liquid falling with sub-freezing temps. Not enough to cause problems with power lines or trees, but enough for ice on bridges and overpasses - probably not surface streets. Of course, if the surface temp drops to 28-29 or lower then surface streets may have issues.

Thanks, still learning to read these graphs, but I agree with Portastorm, any ice on bridges or overpasses here can cause real traffic headaches.

[Texashawk]

Considering weather stations just outside of Brenham are already knocking on the door of the 30's, I'm not sure I trust the Houston temperature forecasts at this time. They seem either too late with the cold or too warm by about 2-4 degrees.

[Tireman4]

Considering weather stations just outside of Brenham are already knocking on the door of the 30's, I'm not sure I trust the Houston temperature forecasts at this time. They seem either too late with the cold or too warm by about 2-4 degrees.

Way too warm. This is IAH. It is 57 there now...25 miles north it is 53 in the Woodlands.

A 30 percent chance of showers. Cloudy, with a temperature falling to around 61 by 5pm. North wind around 15 mph.

[ColdFusion]

Light rain definitely reaching the ground here in North Dallas. Tollway @ 635.

that band of light precip on top of dfw might not be reaching the ground right now, but it is decreasing temps underneath it. Temp in in plano has decreased from 34.5 to 33.7 according to wunderground.

[gboudx]

Latest post from Steve McCauley:

The new data sets are coming in, and they continue to confirm: The Metroplex will become entombed in ice tonight into early tomorrow morning. Rain will be falling while temperatures are in the 20s, freezing solid on impact. Winds will be gusting over 20 mph which will take down tree limbs, sending them into power lines.

Upper-level winds are amplifying into a full-blown McFarland which will send temperatures into the teens by Saturday morning with single digits along the Red River. This is going to be dangerous, folks.

I will be posting more specifics (with graphics) once I get out of class today. Bottom Line: Prepare for this storm!

He replied to someone that the TT model is still showing all rain though. But that seems very unlikely.

Disclaimer: This is my opinion.

[wxman57]

What I find odd about their ice accumulation amounts of 1/4 to 1/2 inch is that all of the major models show low end 3/4 inch QPF with the GFS showing 1.25 inches of QPF. Are they assuming 25-40% of this precip will melt upon contact ? Appears like there should be a wide area of greater than 1/2 inch ice accumulations

Calculating ice accumulations from predicted precipitation amounts is certainly not an exact science. Suffice it to day that if 1" of rain is forecast to fall and surface temps are 28-30 deg that only a fraction of that rain will accumulate on elevated surfaces (trees/power lines). Besides the surface temperature, the rate of rainfall is another factor. Heavier rain will accumulate less than a light rain or drizzle. So predicting ice accumulations is not easy.

[cheezyWXguy]

Light rain definitely reaching the ground here in North Dallas. Tollway @ 635.

that band of light precip on top of dfw might not be reaching the ground right now, but it is decreasing temps underneath it. Temp in in plano has decreased from 34.5 to 33.7 according to wunderground.

yeah seems to be getting a bit stronger. temp in plano is down to 33.2 now

[BrokenGlassRepublicn]

Light rain definitely reaching the ground here in North Dallas. Tollway @ 635.

that band of light precip on top of dfw might not be reaching the ground right now, but it is decreasing temps underneath it. Temp in in plano has decreased from 34.5 to 33.7 according to wunderground.

yeah seems to be getting a bit stronger. temp in plano is down to 33.2 now

Surface temp and humidity at my house haven't budged all morning...but it is clear from the WunderMap that locations under the precip are 3-5 degrees colder than dry locations. Decatur is 33 and Post Oak, just west of there is 27.

[WeatherNewbie]

Light rain definitely reaching the ground here in North Dallas. Tollway @ 635.

that band of light precip on top of dfw might not be reaching the ground right now, but it is decreasing temps underneath it. Temp in in plano has decreased from 34.5 to 33.7 according to wunderground.

yeah seems to be getting a bit stronger. temp in plano is down to 33.2 now

Light rain coming down just north of the PBGT and DNT intersection in Carrolton as well.

[Texashawk]

Katy now reporting 49 degrees. Waller in mid-40's. These temperatures are dropping FAST!!! And the dew points are dropping into the 30's already at many of the NW Houston-area stations.

[gboudx]

With the DFW radar lighting up, I hope we don't start icing up already. The commute this evening could be bad.

[Tireman4]

HGX Morning AFD:


FXUS64 KHGX 051634
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1034 AM CST THU DEC 5 2013

.UPDATE...
SURFACE COLD FRONT CONTINUES TO PUSH RAPIDLY THROUGH SOUTHEAST
TEXAS THIS MORNING AND IS ALREADY MOVING THROUGH THE CITY OF
HOUSTON. TEMPERATURES WILL CONTINUE TO FALL THROUGH THE DAY WITH
LIGHT RAIN EXPANDING IN COVERAGE ACROSS THE REGION. HAVE ADJUSTED
TEMPERATURES TODAY TO REFLECT THE FASTER FRONTAL MOTION AND ALSO
ADJUSTED PRECIPITATION COVERAGE THROUGH TONIGHT. 38

&&

.AVIATION...
COLD FRONT MOVING THROUGH IAH/SGR AT 16Z AND WILL CONTINUE TO
PROGRESS SOUTHWARD. CIGS NORTH OF THE FRONT 1000-1700 FT WHILE SOUTH
OF THE FRONT 400-1000 WITH FOG. LIGHT PRECIP ACCOMPANIES THE FRONT
WITH ISENTROPIC UPGLIDE STRENGTHENING OVERNIGHT AND FRIDAY WHICH
SHOULD BRING -DZ/-RA AND POSSIBLY SOME BANDS OF -SHRA. TEMPERATURES
NEAR CLL AROUND 12Z STILL LOOK VERY CLOSE TO 32 AND PROFILE MIGHT
SUPPORT A SHORT PERIOD OF -FZRA.

45

&&

.MARINE...
DENSE SEA FOG STILL PLAGUING THE UTCW AND THIS FOG SHOULD FINALLY BE
CLEARING WITH THE FRONTAL PASSAGE. EXTENDED THE DENSE FOG ADVISORY
TO AROUND NOON AND HOISTED THE SCA FOR TONIGHT. NORTH WINDS IN THE
WAKE OF THE FRONT INCREASE TO 15 TO 20 KNOTS THIS AFTERNOON THEN
INCREASE FURTHER TONIGHT AND FRIDAY TO 20-25 KNOTS.



http://forecast.weather.gov/product.php ... glossary=1

[GRAYSONCO.WX]

Anyone see the 12Z GEM for next week?