Texas Winter 2014-2015

[TexasF6]

WINTER WEATHER ADVISORY POSTED FOR AUSTIN AREA

[Portastorm]

WINTER WEATHER ADVISORY POSTED FOR AUSTIN AREA

Yep ... things are getting a little more interesting.

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1015 AM CST WED DEC 31 2014

...FREEZING RAIN AND DRIZZLE EXPECTED TODAY THROUGH THE MORNING
OF NEW YEARS DAY...

.A SHALLOW...COLD...ARCTIC AIR-MASS HAS SETTLED OVER SOUTH
CENTRAL TEXAS TODAY...AND WILL REMAIN IN PLACE THROUGH NEW YEARS
DAY. AREAS OF FREEZING RAIN AND FREEZING DRIZZLE ARE DEVELOPING
ACROSS THE SOUTHERN EDWARDS PLATEAU AND THE WESTERN HILL COUNTRY
EARLY THIS MORNING...AND ARE EXPECTED TO CONTINUE FOR MUCH OF
THIS NEW YEARS EVE AND INTO THE LATE MORNING HOURS OF NEW YEARS
DAY. TEMPERATURES MAY ONLY BRIEFLY CLIMB ABOVE FREEZING LATE
TODAY BEFORE QUICKLY FALLING BACK BELOW FREEZING EARLY THIS
EVENING. THERE IS A GOOD CHANCE THAT SIGNIFICANT ICE
ACCUMULATIONS WILL DEVELOP TODAY INTO THIS EVENING...ESPECIALLY
ALONG AND NORTH OF A COMSTOCK TO BOERNE TO BURNET LINE. MOST ICE
ACCUMULATIONS SHOULD BE LESS THAN 1/10 INCH...BUT A AREAS OF
SLEET MIXED IN WITH THE RAIN COULD PRODUCE LOCALLY HIGHER ICE
ACCUMULATIONS OF AROUND 1/4 INCH. WITH STEEP ROAD INCLINES FOUND
OVER MUCH OF THE EDWARDS PLATEAU AND HILL COUNTRY...EVEN A
FREEZING RAINFALL AMOUNT OF ONE HUNDREDTH OF AN INCH COULD
PRODUCE EXTREMELY HAZARDOUS TRAVEL CONDITIONS.

TXZ173-191-192-202>206-010015-
/O.NEW.KEWX.WW.Y.0010.150101T0600Z-150101T1800Z/
WILLIAMSON-HAYS-TRAVIS-KINNEY-UVALDE-MEDINA-BEXAR-COMAL-
INCLUDING THE CITIES OF...GEORGETOWN...SAN MARCOS...AUSTIN...
BRACKETTVILLE...UVALDE...HONDO...SAN ANTONIO...NEW BRAUNFELS
1015 AM CST WED DEC 31 2014

...WINTER WEATHER ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO
NOON CST THURSDAY...

THE NATIONAL WEATHER SERVICE IN AUSTIN/SAN ANTONIO HAS ISSUED A
WINTER WEATHER ADVISORY FOR AREAS WEST OF THE I35
CORRIDOR IN CLOSE PROXIMITY TO THE EDWARDS
PLATEAU...SPECIFICALLY ALONG AND NORTHWEST OF A LINE FROM
BRACKETVILLE...TO LAGUNA...TO HELOTES...TO WIMBERLEY...TO LAGO
VISTA...TO LIBERTY HILL. THE ADVISORY WILL BE IN EFFECT FROM
MIDNIGHT TONIGHT TO NOON CST THURSDAY.

* TIMING...MIDNIGHT TONIGHT THROUGH TOMORROW MORNING. (NEW YEARS DAY)

* MAIN IMPACT...PATCHY SLICK SPOTS ON AREA ROADWAYS DUE TO MINOR
SLEET AND ICE ACCUMULATIONS SPECIFICALLY IN CLOSE PROXIMITY TO
THE EDWARDS PLATEAU.

* WHILE ACCUMULATIONS ARE EXPECTED TO BE MINOR...A VERY LIGHT
GLAZING OF ICE ON EXPOSED SURFACES...SIDEWALKS...AND LIGHTLY
TRAVELLED ROADWAYS MAY RESULT IN POTENTIALLY HAZARDOUS DRIVING
CONDITIONS. THIS AREA OF CONCERN IS NOT EXPECTED TO IMPACT METRO
AREAS OF SAN ANTONIO OR AUSTIN BUT COULD POTENTIALLY IMPACT
TRAVELLERS COMING FROM THOSE METRO AREAS AND TRAVELLING TOWARDS
NORTHERN AND WESTERN RURAL LOCATIONS IN THOSE COUNTIES.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY MEANS THAT PERIODS OF SLEET OR FREEZING
RAIN WILL CAUSE TRAVEL DIFFICULTIES. BE PREPARED FOR SLIPPERY
ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE DRIVING.

[WeatherNewbie]

The difficulty of this event has made for some amusing forecasts from WFAA in DFW. A couple days ago, it was no chance of winter weather in the Metroplex. Then it was a tiny chance of some ice in the far western portions. Now they are pretty much saying they have no clue due to the significant difference in 1 to 2 degrees on the type of precipitation. Pete Delkus has tweeted out anything ranging from entombed in ice to a soaking cold rain. This is of course the correct forecast, but I really don't know why they couldn't have said it several days ago when it was becoming obvious this was the case. A lot of people made plans to be out this evening that they might have not made if they knew there was a chance of winter weather in the Metroplex tonight.

[Tammie]

Let's be smart this time about the Austin winter weather advisory. NOBODY mention the 'L' word or the 'GG', and maybe Porta will have a shot at some fun!

[Portastorm]

Reports coming in that I-10 is at a standstill near Fort Stockton due to ice, accidents.

[iorange55]

The difficulty of this event has made for some amusing forecasts from WFAA in DFW. A couple days ago, it was no chance of winter weather in the Metroplex. Then it was a tiny chance of some ice in the far western portions. Now they are pretty much saying they have no clue due to the significant difference in 1 to 2 degrees on the type of precipitation. Pete Delkus has tweeted out anything ranging from entombed in ice to a soaking cold rain. This is of course the correct forecast, but I really don't know why they couldn't have said it several days ago when it was becoming obvious this was the case. A lot of people made plans to be out this evening that they might have not made if they knew there was a chance of winter weather in the Metroplex tonight.

It's such a difficult forecast. Obviously, the temps are playing a major role, but the amount of precip we are expected to get is what makes this situation scary.

This could be a major event if the temps drop lower and/or don't rise as fast tomorrow.

[TeamPlayersBlue]

Dew point is now at 20 here, is it possible that wet bulbing lowers are temperatures so much here that the warm air advection doesn't get us back above freezing?

Correct.

[TheProfessor]

The 12z RGEM continues to show a significant ice storm that looks to affect folks along I-35E and Westward, it has 1-2 inches of QPF in those areas too . I don't know how trust worthy this model is, but if the other short range start trending toward this, especially the RAP then Winter Storm Warnings might be needed in Parker, Wise, Denton, Collin and maybe Tarrant.

[SouthernMet]

Dew point is now at 20 here, is it possible that wet bulbing lowers are temperatures so much here that the warm air advection doesn't get us back above freezing?

This is a great question, and it's something we are worried about... Esp if the predominate precip were sleet...

[WeatherNewbie]

The difficulty of this event has made for some amusing forecasts from WFAA in DFW. A couple days ago, it was no chance of winter weather in the Metroplex. Then it was a tiny chance of some ice in the far western portions. Now they are pretty much saying they have no clue due to the significant difference in 1 to 2 degrees on the type of precipitation. Pete Delkus has tweeted out anything ranging from entombed in ice to a soaking cold rain. This is of course the correct forecast, but I really don't know why they couldn't have said it several days ago when it was becoming obvious this was the case. A lot of people made plans to be out this evening that they might have not made if they knew there was a chance of winter weather in the Metroplex tonight.

It's such a difficult forecast. Obviously, the temps are playing a major role, but the amount of precip we are expected to get is what makes this situation scary.

This could be a major event if the temps drop lower and/or don't rise as fast tomorrow.

Agreed. If that colder air in Oklahoma (15 degrees cooler in OKC compared to DFW) continues to slowly sink south over the next 12 hours, it could be a major ice event for the Metroplex tonight assuming the QPF verifies.

[Tammie]

Still sitting at 28 in Denton. Progged temps were 36 at 11:00 this morning. Pretty big bust IMO.

[Ntxw]

Dew point is now at 20 here, is it possible that wet bulbing lowers are temperatures so much here that the warm air advection doesn't get us back above freezing?

This is a great question, and it's something we are worried about... Esp if the predominate precip were sleet...

I was thinking about this several days ago. I don't think wet bulbing will have a lot of effect on the immediate surface regarding freezing rain but it may have an impact on the air column. Freezing rain and frz drizzle has been the concern for the WFO but Im wondering if sleet may actually be more prevalent

[TexasF6]

Dallas is at freezing now per NWS site! Hmmmmm....

[TheProfessor]

I rarely use weather.com and in the past I've noticed their temperatures are usually too warm usually making them inadequate to decide on winter weather, my sister convinced me too look at it because she thought they were forecasting snow and it had a high of 34 on Thursday, That's 4 degrees lower than NWS and could make for a very serious situation on Thursday depending on when that high was reach if that verified. Also I was wondering, if we got ice on the ground in the morning, couldn't that keep temps at the surface colder on Thursday, which could keep freezing rain longer?

[Portastorm]

I gotta say that up until about two hours ago I thought we'd be fine in the Austin metro area tonight/tomorrow morning with maybe a little freezing rain/light sleet mixed with rain, at the worst. But now I'm beginning to wonder. I'm hearing "chatter" that the storm system out west is moving further south than the models progged and dewpoints continue falling here in south central Texas and are approaching the mid 20s. Any wet-bulbing effect (and yes, I've seen it happen with freezing rain as well as sleet) here could definitely drop surface temps to 32 or slightly lower. And if the low system is further south into Texas that would mean a potential greater impact of wintry weather a little further south and east. I'm really starting to wonder though ...

[aggiecutter]

The "Ozark Shadow" as Bastardi refers to it might save NE Texas from a catastrophic ice storm as it has in the past. I mentioned this phenomenon a couple years ago and some on here scoffed at it. Actually, two things are at play here. The Quachita Mountains are on east-west range running from Little Rock, Arkansas to just outside Talihina, Oklahoma in SE Oklahoma. Some of the peaks in this region are well above 2,000', with Rich Mountain in West Arkansas-SE Oklahoma being over 2,600'. Depending on the trajectory of the low level arctic air, it sometimes has problems traversing this mountain range. Also, depending on the trajectory of the wind, you get what is more or less a down-sloping effect off the Ozark Plateau in Northern Arkansas. The effects downstream can have significant effects on temperatures in east Texas and western Louisiana all the way to the coast.

[TeamPlayersBlue]

I saw that tweet and yeah i completely believe in the ozark shadow. There was a large arctic event last year where it kept temps here in SE Tx above what they expected for some period of time. Looking back at other events, this one seems to be kind of similar to Dec 1990. More west based and leaving us here with a cold rain. A trough or cut off low in the west is keeping much of the cold air there. It's colder in Yuma this morning where my family lives than here in Houston! Lol

Anyways, the pattern looks like lots of fun for us. For this event, everybody stay safe and have fun!

[Portastorm]

I know we're all focused on the immediate event (as we should be), but if y'all want some entertainment ... check out the 12z GFS. It has a dhweather-approved "Cat 5 in the Gulf!" winter storm for Texas around January 12th-13th.

[orangeblood]

After analyzing MOS guidance numbers for this mornings model runs, we obviously still have some discrepancies in how this event will unfold....NAM seems to be doing a better job with current temps (still too warm) but is really cranking the warm advection tomorrow and warming things up as the precip intensifies, warming temps above freezing across majority of North Texas by afternoon. However, the GFS actually shows the wet bulbing effect taking over, lowering temps as precip falls, keeping dew points in the 20's for DFW all day tomorrow. If GFS verifies/wet bulbing negates the warm advection and frozen precip accumulates, I don't see how temps will rise above freezing in the Metroplex until Friday at the earliest.

[Ralph's Weather]

Analyzing MOS guidance numbers for this mornings model runs, we obviously still have some discrepancies in how this event will unfold....NAM seems to be doing a better job with current temps (still too warm) but is really cranking the warm advection tomorrow and warming things up as the precip intensifies, warming temps above freezing across majority of North Texas by afternoon. However, the GFS actually shows the wet bulbing effect taking over, lowering temps as precip falls, keeping dew points in the 20's for DFW all day tomorrow. If GFS verifies/wet bulbing negates the warm advection and frozen precip accumulates, I don't see how temps will rise above freezing in the Metroplex until Friday at the earliest.

I agree with this, I think a large portion of the Metroplex struggles to reach freezing tomorrow especially east of Dallas. Locally in E TX along the I-20 corridor temps will not rise hardly tomorrow though the "Ozark Shadow" or whatever we are calling it may prevent freezing temps as DPs are around 30 and east winds will not advect drier air. The models are showing the 925mb freezing line in our area so a bit of sleet could mix in if we get heavier showers early in the day.