Southern Plains winter wx thread (2008-2009)

[ntxweatherwatcher]

... Ice Storm Warning in effect from 6 PM this evening to 12 PM
CST Wednesday...
... Winter Storm Watch no longer in effect...

The National Weather Service in Fort Worth has issued an Ice
Storm Warning for significant icing across the northern two thirds
of North Texas from 6 PM this evening to 12 PM CST Wednesday. The
Winter Storm Watch for Tuesday and Tuesday night is no longer in
effect.

Periods of freezing rain will develop late this evening and
overnight along and northwest of a Lampasas... hillboro... to Canton
line. Temperatures will remain below freezing through Wednesday
morning and periods of light freezing rain will continue. Total
ice accumulations of one quarter inch are likely with isolated one
half inch amounts.

All precipitation will end Wednesday morning but temperatures should
remain below freezing until afternoon.

An Ice Storm Warning means severe winter weather conditions are
expected or occurring. Significant amounts of ice accumulations
will make travel extremely dangerous or impossible.

[Ed Mahmoud]

Hi Ed,

Yes, a pro-met would have to chime-in with the actual calculations that will tell you.

I can tell you this much, it depends on a number of factors; not just the thickness. The temp-dewpoint spread and also how supercooled the droplets are enter into the equation as well -- but I'm sure you already knew that much

I can eyeball it and be right most of the time, but as far as doing the calculations, not so much...I go into model watching mode (& observations) at that point.

FWIW I think the accuracy rate of determining one over the other in borderline situations isn't the best.

This link may help: http://www4.ncsu.edu/~nwsfo/storage/cst ... terial.ppt

Childress is -4º (24º F) and freezing drizzle. I don't know how thick or thin the cold air is, but I'm always impressed by sub-freezing liquid when the air is that cool.

[somethingfunny]

Well, it doesn't look like I'm going ANYWHERE after sunset tonight!

[Extremeweatherguy]

Here is some video I shot of icy cars here in SE OKC: http://www.youtube.com/watch?v=eX62buKquBE

[iorange55]

Well, looks like it'll be getting bad here tomorrow. I'm already planning on staying home, i got some steak and potatoes i can cook tomorrow, that is if the power stays on.

[ntxweatherwatcher]

I hope my kids school close for the day, not start and send them home early!! Same for my husband...I hope we don't lose power!!

[Extremeweatherguy]

The 00z GFS is showing a big burst of precipitation forming over the area tomorrow morning through about noon. Southeast Oklahoma City, where I am located, is shown to get 0.25-0.50" of precipitation with this burst. Could be an interesting morning if this plays out:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_018l.gif

It is also worth noting that the latest RUC model run seems to agree with this idea as well; showing a big increase in precipitation over central and southern Oklahoma tomorrow morning.

[Ed Mahmoud]

The 00z GFS is showing a big burst of precipitation forming over the area tomorrow morning through about noon. Southeast Oklahoma City, where I am located, is shown to get 0.25-0.50" of precipitation with this burst. Could be an interesting morning if this plays out:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_018l.gif

It is also worth noting that the latest RUC model run seems to agree with this idea as well; showing a big increase in precipitation over central and southern Oklahoma tomorrow morning.

NAM and GFS quite different in total precip...w/ GFS huge ice storm for Dallas area

Midnight-early Wednesday morning

GFS

NAM

[Extremeweatherguy]

Some heavier freezing rain/sleet showers are starting to pop south and east of OKC. Might even be some thunder in a few of these...

http://www.wunderground.com/radar/radbl ... rainsnow=0

...It will be interesting to see if these heavier showers start to expand in coverage back westward over the next few hours.

[Extremeweatherguy]

It looks like things are about to get really interesting for OKC...

http://www.wunderground.com/radar/radbl ... rainsnow=0

[Extremeweatherguy]

I just looked outside and it is white everywhere! I think it is snow! I had been asleep for the last hour, so this is definitely a surprise to wake up and see.

[somethingfunny]

I just looked outside and it is white everywhere! I think it is snow! I had been asleep for the last hour, so this is definitely a surprise to wake up and see.

Bah humbug. We're hovering around freezing and will be for some time based on all the liquid on the ground currently.

Some sort of mist is flying through the air under the streetlights.

[iorange55]

I just looked outside and it is white everywhere! I think it is snow! I had been asleep for the last hour, so this is definitely a surprise to wake up and see.

Lol, I saw on the NWS that oklahoma city was reporting light snow, I guess that was accurate. Lucky maybe my miracle will happen after all. The new GFS 06z run is showing a lot of precip for us.

[Extremeweatherguy]

We're getting a few flashes of lightning now too. This is certainly strange.

[Extremeweatherguy]

Now we are getting sleet. I can hear it hitting the windows.

[iorange55]

Nws update dallas.

...PROLONGED PERIOD OF FREEZING RAIN AND SOME SLEET TO CREATE SIGNIFICANT
IMPACTS ACROSS NORTH TEXAS LATER TODAY THROUGH WEDNESDAY
MORNING...

.SYNOPSIS...A SHALLOW ARCTIC AIRMASS CONTINUES TO SEEP SOUTH ACROSS
SOUTHERN NORTH TEXAS THIS MORNING. MEANWHILE...AN UPPER LEVEL STORM
SYSTEM OVER THE SOUTHERN ROCKIES WILL CONTINUE MOVING IN FROM THE
WEST. HIGH TEMPERATURES WILL LIKELY OCCUR THIS MORNING... THEN FALL
THROUGH THE DAY AS THE ARCTIC FRONT SLIDES SLOWLY SOUTH TOWARD THE
UPPER TEXAS COAST AND CENTRAL TEXAS. MOST AREAS WILL SEE RAIN OR
FREEZING RAIN THIS MORNING...WITH A GRADUAL CHANGEOVER TO FREEZING
AND SLEET LATE THIS AFTERNOON AND THROUGH TONIGHT. ICE AND SLEET
ACCUMULATIONS BETWEEN 0NE TENTH AND ONE QUARTER OF AN INCH ARE PROBABLE
MOST AREAS...WITH ISOLATED AMOUNTS TO ONE THIRD OF AN INCH POSSIBLE.

WINTER PRECIPITATION SHOULD END ACROSS THE NORTHWEST HALF OF NORTH TEXAS
AFTER DAYBREAK WEDNESDAY...WITH PRECIPITATION ENDING ACROSS THE SOUTHEAST
HALF OF NORTH TEXAS BY WEDNESDAY AFTERNOON.

[somethingfunny]

My county gets its own update!

TXZ093-271745-
/O.CAN.KFWD.IS.W.0001.090127T1200Z-090128T1800Z/
/O.NEW.KFWD.WS.W.0001.090127T1200Z-090128T1200Z/
GRAYSON-
INCLUDING THE CITIES OF...SHERMAN...DENISON
338 AM CST TUE JAN 27 2009

...WINTER STORM WARNING IN EFFECT UNTIL 6 AM CST WEDNESDAY...
...ICE STORM WARNING IS CANCELLED...

THE NATIONAL WEATHER SERVICE IN FORT WORTH HAS ISSUED A WINTER
STORM WARNING FOR SIGNIFICANT ICING FROM FREEZING RAIN AND
SLEET...WHICH IS IN EFFECT UNTIL 6 AM CST WEDNESDAY. THE ICE STORM
WARNING FOR FREEZING RAIN ONLY HAS BEEN CANCELLED.

TEMPERATURES ARE EXPECTED TO FALL AND REMAIN BELOW FREEZING
THROUGH TONIGHT...AS ARCTIC AIR SETTLES OVER THE REGION. ISOLATED
THUNDERSTORMS WILL BE POSSIBLE...PROVIDING A POTENTIAL FOR HEAVY
SLEET TO MIX IN WITH ANY FREEZING RAIN. ANY ISOLATED THUNDERSTORMS
WILL ENHANCE THE POTENTIAL FOR SIGNIFICANT AMOUNTS OF ICING THROUGH
TONIGHT. TOTAL ICE ACCUMULATIONS UP TO ONE QUARTER INCH ARE
LIKELY.

THE FREEZING RAIN AND SLEET WILL END AFTER SUNRISE WEDNESDAY...YET
TEMPERATURES SHOULD REMAIN BELOW FREEZING UNTIL AFTERNOON.

ROADS...BRIDGES...AND OVERPASSES IN THE WARNING AREA WILL BE
SLICK AND HAZARDOUS. EXERCISE EXTREME CAUTION IF TRAVEL IS
NECESSARY. KEEP AN EXTRA BLANKET...FLASHLIGHT...FOOD...AND WATER
IN YOUR VEHICLE IN CASE YOU BECOME STRANDED.

A WINTER STORM WARNING MEANS SIGNIFICANT AMOUNTS OF ICE AND SLEET ARE
EXPECTED OR OCCURRING. THIS WILL MAKE TRAVEL VERY HAZARDOUS OR IMPOSSIBLE.

$$

I'm not sure if sleet is any better than freezing rain. It's less likely to stick to the trees and power lines, but as long as the two are mixed together it will just solidify on the ground, making travel impossible....

Please, note that the remainder of DFW is still under an Ice Storm Warning.

[Extremeweatherguy]

Its all windblown sleet now in OKC. We probably have about a good 1/2" to 1" of sleet on the ground already and even more looks to be on the way...

http://www.wunderground.com/radar/radbl ... rainsnow=0

BTW, here is a brief video of the sleet that I just went outside and shot a few minutes ago: http://www.youtube.com/watch?v=oaGvi7vL9D4

[somethingfunny]

Hey EWG, iorange: Have you guys slept at all tonight? My excuse is I have an English paper due tomorrow/tonight.


The temperature at the airport 5 miles south of my home is 32° (with "Unknown Precip") - the ground is covered with water, and a peek outside showed that even the railings (which I imagine would freeze first) are merely wet complete with freely dripping liquid water.

As a weather n00b I have a question: Wouldn't the presence of all this water on the ground tend to moderate the air temperatures immediately above ground level?

[iorange55]

I always stay up late anyways so this is nothing new for me lol. Sometimes I only get 2 or 3 hours of sleep. I'll probably need to catch a nap pretty soon before all the good stuff starts. As for your question, I'm not sure about that I don't think it matters all that much...but I'm sure EWG knows.