Texas winter wx thread#4 - big changes on the way eventually

[TexasStooge]

The chance of flurries is taken back out of the forecast for DFW, of course residents in and around the Extreme Northwest portion of North Texas may get lucky and get a chance of wet snow. OK, I take it back, a 20% chance of rain/snow is back in DFW's forecast...ok, it's back out...it's back in...STOP CHANGING THE FORECAST!!! IT'S DRIVING ME CRAZY!!!

DALLAS/FORT WORTH
Today: 48°F
Tonight: 40°F
Christmas Day: 55°F

WICHITA FALLS
Today: 48°F
Tonight: 30°F
Christmas Day: 52°F

ARCHER CITY
Today: 48°F
Tonight: 31°F
Christmas Day: 52°F

VERNON
Today: 49°F
Tonight: 30°F
Christmas Day: 51°F

[JenBayles]

Hey! I think Extreme's weather balloon landed at NOAA!


West Houston NWS:

Christmas Day: A slight chance of rain and sleet before noon. Mostly cloudy during the morning, then mostly sunny during the afternoon, with a high near 55. Windy, with a west wind 5 to 10 mph becoming northwest between 20 and 25 mph. Winds could gust as high as 30 mph. Chance of precipitation is 20%.

[JenBayles]

As usual AFM chimes in to crush us all with reality. <sigh>

[Extremeweatherguy]

I know! I just saw that! 20% chance of rain/sleet sounds good to me. Let's just hope I end up being one of the places that sees it.

This is what the early morning discussion said:

A SECOND S/WV WILL APPROACH THE REGION MONDAY
MORNING WITH AN ADDITIONAL CHANCE OF LIGHT RAIN. ECMWF/NAM AND 00Z
GFS SHOW 850 TEMPS BETWEEN ZERO AND -2 WITH 1000-500 THICKNESS
AROUND 537 DM. FREEZING LEVEL IS BETWEEN 3-4000 FEET...SO THE
PRECIP TYPE WILL PROBABLY BE A MIX OF RAIN AND SLEET. AT THIS
TIME...FEEL THAT FROZEN PRECIP WILL LIKELY MELT BEFORE REACHING
THE SURFACE. NOT CONFIDENT WITH THE THE PRECIP TYPE OR EVEN IF WE
CAN GENERATE PRECIP AT ALL.

update: I just saw AFMs comment too. Let's just hope the NWS ends up right on this one so that I don't need my hot air balloon.

[Air Force Met]

I know! I just saw that! 20% chance of rain/sleet sounds good to me. Let's just hope I end up being one of the places that sees it.

This is what the early morning discussion said:

A SECOND S/WV WILL APPROACH THE REGION MONDAY
MORNING WITH AN ADDITIONAL CHANCE OF LIGHT RAIN. ECMWF/NAM AND 00Z
GFS SHOW 850 TEMPS BETWEEN ZERO AND -2 WITH 1000-500 THICKNESS
AROUND 537 DM. FREEZING LEVEL IS BETWEEN 3-4000 FEET...SO THE
PRECIP TYPE WILL PROBABLY BE A MIX OF RAIN AND SLEET. AT THIS
TIME...FEEL THAT FROZEN PRECIP WILL LIKELY MELT BEFORE REACHING
THE SURFACE. NOT CONFIDENT WITH THE THE PRECIP TYPE OR EVEN IF WE
CAN GENERATE PRECIP AT ALL.

update: I just saw AFMs comment too. Let's just hope the NWS ends up right on this one so that I don't need my hot air balloon.

Well...if someone will offer an explaination on how sleet forms without first melting the snow...they will be right.

Otherwise...the only other way you get sleet is a hidden melting layer above the 3-4000 foot freezing level....and right now...no model is showing it.

Anyone care to explain how it happens other than that process I'm all ears...

Sorry to be the grinch...but thats the meteorology behind sleet. It has nothing to do with the thickness or the 850mb temps...it has everything to do with melting and refreezing....and for once (when we DON'T want it)...we actually don't have a warm layer. Too bad it's going to be 10 degrees too warm for snow....which is another thing...I don't think I've ever seen sleet forecast with a LOW temp forecasted of 47 degrees...at least for Angleton...

Think about it....a LOW of 47 and sleet? Does that make any sense given a 4000 foot freezing level?

[Extremeweatherguy]

could evaporative cooling play any role in their forecast? Is dry air expected to be filtered in with the next system? Or may be they are thinking there will be a warm layer that the models aren't picking up on? I just don't understand how all the trained mets over at the NWS could get something like this wrong. Wouldn't this be one of the basic skills...knowing when sleet can form? I guess we will just have to see, but your right..if there is nothing else that they're seeing then it will be hard to get any sleet to the surface.

At this point I will just try to hope for the best!

[Yankeegirl]

I just noticed the rain sleet in the forecast too, I was like WTF????

[JenBayles]

Hey! There you are Extreme! I've been worried you had a heart attack and keeled over on us when you saw the forecast this morning.

So tell me - have you been talking to the NWS boys or something?

[Air Force Met]

could evaporative cooling play any role in their forecast? Is dry air expected to be filtered in with the next system? Or may be they are thinking there will be a warm layer that the models aren't picking up on? I just don't understand how all the trained mets over at the NWS could get something like this wrong. Wouldn't this be one of the basic skills...knowing when sleet can form? I guess we will just have to see, but your right..if there is nothing else that they're seeing then it will be hard to get any sleet to the surface.

At this point I will just try to hope for the best!

If evap cooling was to take place...it would be on the back side of the low and you would be more likely to get snow than sleet...because all evap cooling would do is lower the freezing level closer to the sfc...which would allow the snow to melt closer to the sfc.

So...in this kind of temp profile...snow is more possible than sleet because there is no opportunity to melt and refreeze into sleet. The only thing I can think of is the skeleton crew is working the holidays.

It's just not that cold. It's 46 in Amarillo! It's 54 in Lubbuck. There isn't a lot of cold air around. Again...I don't ever understand forecasting sleet when you forecast a LOW of 47. Yes...the thickness values are low...but the 500mb heights are low...so that's why...it has nothing to do with cold air being in place.

Who knows...maybe there is a warm layer somewhere...but looking at sounding across the area this morning...short of some radical radiational cooling overnight...there won't be one.

[southerngale]

Well, Lake Charles NWS doesn't have sleet in the forecast for Beaumont...just rain. Given the temps and everything AFM said, I'm guessing they'll be right. If something other than rain somehow sneaks through though, I'll be sure to let y'all know.

AFM, you need a Grinch avatar.


Seriously, thanks for explaining things in a way that we can all understand...much appreciated!

[Portastorm]

What is of interest to me is that the NAM appears to have won the "guess the track of the upper low" contest as it appears to be just west-southwest of Austin now (1:40 pm) and moving slowly east. Well, at least that is what the radar trends show me.

Remember the Euro had it going through far south Texas and the GFS runs from 36 hrs ago had it going across the middle part of the state.

Meanwhile, I'm enjoying this chilly rain, firing up the pecan wood in my smoker, and getting ready to make our family's Christmas brisket! At least it feels somewhat like Christmas outside!!

EWG -- I hope Santa brings you some sleet or snow before this is all over!

[Air Force Met]

EWG -- I hope Santa brings you some sleet or snow before this is all over!

Maybe some will fall off the back of the sled when he stops by his house...

[Yankeegirl]

Lol... or maybe he can get some of that instant snow they sell at the mall???

[JenBayles]

What's the latest news from Mt. Bastardi, Portastorm?

[Janie2006]

EWG -- I hope Santa brings you some sleet or snow before this is all over!

Maybe some will fall off the back of the sled when he stops by his house...

Hahahahahahahaha!

EWG just can't get a break.

[KatDaddy]

Sleet removed from the forecast on the Houston-Galveston NWS page.

[Extremeweatherguy]

Sleet removed from the forecast on the Houston-Galveston NWS page.

not where I am!!!! Instead it got better...

I now have a rain/snow forecast!

yes!!!

Christmas Day: A chance of rain, mixing with snow after 9am, then gradually ending. Cloudy, then gradually becoming partly sunny, with a high near 52. Northwest wind between 10 and 15 mph, with gusts as high as 20 mph. Chance of precipitation is 30%.

(looks like they must be counting on evap. cooling)

http://www.srh.noaa.gov/forecast/MapCli ... X&site=HGX

May be my dreams of a white christmas will come true..

[Brent]

Snow with temperatures in the 40's?

[Extremeweatherguy]

Snow with temperatures in the 40's?

I am sure if it actually happened it would probably drop into the 30s from the snow cooling the atmosphere, but at this point they are going with lower 40s and a rain/snow mix which is somewhat believable considering it has happened before in evap. cooling situations.

I am just happy to see the word "snow" in the forecast for Christmas day! Even if it doesn't happen, knowing that there is a chance that it may is exciting.

[Yankeegirl]

Mine also has a chance of snow as well.... Wow.... If it happens I think alotta people are going to be eating crow? Including me!! Hey, It can happen, the Texans beat the COlts today!!!