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

[Yankeegirl]

EWG, you better take a snapshot of the forecast with snow in it, its not going to happen again for another few years!!

[Johnny]

Yea, snow is in my forecast for the morning period also. AFM, why are they trying to tease us like this? It's not gonna happen folks.

[Extremeweatherguy]

BTW, Austin and Fort worth NWS offices are also now calling for a rain/snow mix tomorrow.

Here is Austin's Forecast:

Christmas Day: A slight chance of sprinkles and flurries before 10am. Mostly cloudy, then gradually becoming mostly sunny, with a high near 56. Northwest wind between 10 and 20 mph, with gusts as high as 25 mph.

Here is Waco's Forecast:

Christmas Day: A slight chance of sprinkles and flurries before 10am. Cloudy through mid morning, then gradual clearing, with a high near 52. Windy, with a north northwest wind between 15 and 25 mph, with gusts as high as 30 mph.

Here in and around Houston though we may have more luck. We will have more moisture to work with leading to possible rain/snow showers instead of just sprinkles and flurries.

[Air Force Met]

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..

Well...I still don't think it will happen...but a snow flurry making it to the ground in this environment makes a LOT more sense than sleet...given the temp profile.

Early in the morning...on the back side of the low in the northern zones it is possible to have some mixed in...but the NAM has the freezing level (at Conroe) at about 4500 feet at 12z...and 4000' at 15Z. The GFS keeps it at 4500' for 12Z at 15Z. BY 18Z it is 3300'. IT stays at that level and then drys out with the low passage.

So...it appears that the lowest the freezing level gets is about 3500'. The environment appears saturated and there is no dry air advecting in until the low passes...so rule out any evap-cooling of the air column.

So...unless you go up a couple thousand feet...I still think snow is a stretch...but it is less of a stretch than sleet....at least snow is possible.

One clue for us ought to be the fact there is no sleet or snow anywhere in the state. If the airmass is not cold enough to produce sleet or snow at a higher elevation with the given dynamics...how is it going to produce snow/sleet at a lower elevation one day later when it has had further chances to modify away from its source region? By the time any air can advect in from the plains that is colder...it is a lot dryer and the upper level energy is long gone.

[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..

Well...I still don't think it will happen...but a snow flurry making it to the ground in this environment makes a LOT more sense than sleet...given the temp profile.

Early in the morning...on the back side of the low in the northern zones it is possible to have some mixed in...but the NAM has the freezing level (at Conroe) at about 4500 feet at 12z...and 4000' at 15Z. The GFS keeps it at 4500' for 12Z at 15Z. BY 18Z it is 3300'. IT stays at that level and then drys out with the low passage.

So...it appears that the lowest the freezing level gets is about 3500'. The environment appears saturated and there is no dry air advecting in until the low passes...so rule out any evap-cooling of the air column.

So...unless you go up a couple thousand feet...I still think snow is a stretch...but it is less of a stretch than sleet....at least snow is possible.

One clue for us ought to be the fact there is no sleet or snow anywhere in the state. If the airmass is not cold enough to produce sleet or snow at a higher elevation with the given dynamics...how is it going to produce snow/sleet at a lower elevation one day later when it has had further chances to modify away from its source region? By the time any air can advect in from the plains that is colder...it is a lot dryer and the upper level energy is long gone.

correct me if i'm wrong AFM, but isn't the colder airmass not really even in the state yet?

http://www.hpc.ncep.noaa.gov/sfc/satsfcnps.gif

According to what I have been seeing it shouldn't reach the northern areas of the state until tonight and then swing SE after that (reaching Houston just after sunrise).

Even the Amarillo NWS image here says the front should not arrive there until evening: http://www.srh.noaa.gov/ama/fxc/ghwo.php

wouldn't it be the drying, colder air behind this front that brings us the chance of a changeover to snow before the precip. ends?

Also, Dan Meador over at KHOU is saying that the "dew point depression" would favor either sleet or snow tomorrow morning.

[Air Force Met]

Yea, snow is in my forecast for the morning period also. AFM, why are they trying to tease us like this? It's not gonna happen folks.

NOt sure...but I can guarantee they were giggling when they wrote it.

Don't look for the evap cooling situation that brought the snow in 2004...the column will already be saturated and the most cooling you could get would be lowering the freezing level to about 2500' and temps near 40...and that is if it was pouring rain outside. The NAM is calling for .01" of precip b/w 06-12Z and none afterwards. The GFS is calling for the same. Not the kind of situation that sets of evap cooling.

Extreme northern zones...maybe eastern Texas closer to the upper low where the lapse rates are steeper and the freezing level is lower...more likely.

Let's be honest...this hasn't been the best NWS office when it comes to winter forecasting. I think it is them. I just checked the Tyler forecast, the Shreveport forecast, the Lufkin forecast, Jasper...nobody has any mention of it. DFW mentions it...but...that makes a little more sense.

I hope it gets a little colder tonight...but I think we are going to have a precip problem. There won't be any.

[Extremeweatherguy]

From the afternoon HGX AFD:

SHORTWAVE IN CNTRL TX EJECTING EASTWARD LATE THIS AFTERNOON WHICH
SHOULD BRING ANOTHER ROUND OF PRECIP ACROSS SE TX THIS EVENING AS IT
MOVES THRU. WV IMAGERY SHOWS ANOTHER SHORTWAVE IN COLORADO DIVING
SOUTHWARD TO TAKE THE FIRST ONES PLACE IN CNTRL TX. THIS DISTURBANCE
SHOULD ALSO KICK OUT AND MOVE EWD ACROSS THE REGION XMAS MORNING AND
INTO LA DURING THE AFTERNOON. COLD FRONT WILL BE FILTERING IN ABOUT
THE SAME TIME. TRICKY PART IS FORECASTING WHETHER THERE WILL BE
PRECIP OR NOT. AND IF SO - WHAT FLAVOR? MODELS SHOWING PW`S FALLING
TO AROUND 0.7" AS THIS EVENINGS SHORTWAVE PUSHES EAST. HOWEVER FCST
SOUNDINGS ACROSS THE NORTHERN 1/2 TO 2/3 OF THE CWA SHOWING A FAIRLY
SATURATED LAYER BETWEEN 3400-22000 FT THAT IS ALL BELOW FREEZING
GENERALLY AS THE DISTURBANCE MOVES THROUGH. 1000-500MB THICKNESS
ALSO BELOW 540DM AROUND THAT TIMEFRAME. SO...THERE IS A NARROW
OPPORTUNITY IF PRECIPITATION DOES FALL THERE IS A CHANCE IT`LL BE
MIXED WITH SOME LIGHT SNOW OR FLURRIES DURING THE MID MORNING TO
EARLY AFTERNOON HOURS. LIMITING FACTOR...IN ADDITION TO SPARSE
MOISTURE AVAILABILITY...APPEARS TO BE LACK OF LIFT WITH THE ONGOING
CAA. SFC TEMPS WILL BE WELL ABOVE FREEZING SO DO NOT ANTICIPATE ANY
SIGNIFICANT ACCUMULATIONS NOR ANY ICING PROBLEMS.

Still "iffy" but the chance is definitely there.

[JenBayles]

Is anyone else getting annoyed with the lack of radar from HGX today? Since this morning it's been down, then the message it was "maintenance", and the last couple of hours the topo page is all we get. Guess our NWS guys are enjoying the holiday - or maybe busy whipping up some flurries for Exteme!

[TexasStooge]

The chance of snow has moved to Christmas Morning in DFW. Seems we could get a chance of a White Christmas after all.

DALLAS/FORT WORTH
Tonight: 38°F
Christmas Day: 49°F

Of course, I wouldn't hold my breath on that forecast.

Is anyone else getting annoyed with the lack of radar from HGX today? Since this morning it's been down, then the message it was "maintenance", and the last couple of hours the topo page is all we get. Guess our NWS guys are enjoying the holiday - or maybe busy whipping up some flurries for Exteme!

I've noticed the same thing on my weather site.

[Air Force Met]

correct me if i'm wrong AFM, but isn't the colder airmass not really even in the state yet?

http://www.hpc.ncep.noaa.gov/sfc/satsfcnps.gif

According to what I have been seeing it shouldn't reach the northern areas of the state until tonight and then swing SE after that (reaching Houston just after sunrise).

Even the Amarillo NWS image here says the front should not arrive there until evening: http://www.srh.noaa.gov/ama/fxc/ghwo.php

wouldn't it be the drying, colder air behind this front that brings us the chance of a changeover to snow before the precip. ends?

Also, Dan Meador over at KHOU is saying that the "dew point depression" would favor either sleet or snow tomorrow morning.

1) You're right...that's why I said "By the time any air can advect in from the plains that is colder...it is a lot dryer and the upper level energy is long gone."...That means the cold air that is going to advect down will be too late to play in the game. It won't factor in because there won't be any precip.

2) The Dew point Depression is favorable for sleet...IF there was a melting layer then a re-freezing layer...which there isn't. Don't know if Dan has looked at a forecast Skew-T but there isn't one model that shows a warm layer that could melt the snow aloft...then alllow for it to refreeze into snow.

Also...the WBZ (which is what he is alluding to...I guess...with the dew point depression remark) is still high...near 2500'...because the air column is still saturated. It's only dry near the sfc.

[AL Chili Pepper]

I know Jackson, MS is a little north of Houston, but they have a rain/snow mix forecast for tomorrow night. Wish I was off on Tuesday....I might would take a road trip.

[JenBayles]

Still hanging at 46 under the Dome today. So much for that 52 degree high! What a GREAT day for Christmas Eve!

[Extremeweatherguy]

18z GFS showing more moisture sticking around tomorrow:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _018.shtml
^^sunrise^^

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _024.shtml
^^around noon^^

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _030.shtml
^^around 6pm^^

Though it is not much...it shows most places getting a little bit of precip. throughout the day tomorrow. May be moisture sticking around won't be as big of an issue as first thought?

ALSO: as we have seen with today's highs...forecast temperatures are not always correct. Who knows..may be that low of 42F tonight will bust and we will wake up in the 30s. Temperatures will be another big thing to watch. The colder they are, the better the chance of wintry precipitation reaching the ground.

[Extremeweatherguy]

cold front is through parts of the TX panhandle already. Amarillo's winds have shifted to the north at the last report and Dalhart, TX is currently getting 47mph gusts out of the north with a temperature of 36-degrees.

[aggiecutter]

Looking at the 12Z and 18Z runs of the GFS(see EWG's post above), I might get some moderate snow tomorrow. Maybe even enough to get an accumulation on grassy surfaces. Of course, this is all contingent on the models being right, but I am encouraged by the last 2 model runs. The trend is my friend.

[TexasStooge]

Still hanging at 46 under the Dome today. So much for that 52 degree high! What a GREAT day for Christmas Eve!

You too, huh?

[KatDaddy]

Never say never I say but stay very realistic. Snow is very very difficult to forecast here in SE TX.......really its not the forecast but the conditions we need at many different levels for snow to occur. 2004 for a dream event for the Upper TX Coast. Perhaps all will align again tomorrow and a few flurries may fall on Christmas day. All I can say EWG is to hold your breath but not to long.....you may likely passout

Hey I would love to see another significant snowfall especially for my daughter who will be 3 next year.

[Extremeweatherguy]

the strangest thing is that it is raining here right now, yet there is no rain over my area on radar. This has been happening for most of the day too...

[JenBayles]

I don't care if it snows or doesn't snow. I got what I wanted: a cold, gloomy, and even rainy holiday that is perfect for holing up by the fireplace. Now that we look to stay that through tomorrow, I'm a pretty happy camper.

[Extremeweatherguy]

Never say never I say but stay very realistic. Snow is very very difficult to forecast here in SE TX.......really its not the forecast but the conditions we need at many different levels for snow to occur. 2004 for a dream event for the Upper TX Coast. Perhaps all will align again tomorrow and a few flurries may fall on Christmas day. All I can say EWG is to hold your breath but not to long.....you may likely passout

Hey I would love to see another significant snowfall especially for my daughter who will be 3 next year.

I know, it is very difficult and will likely be a long shot. However, this time there is a better chance than usual and that is enough to make me watch this closely. Should be interesting to see what's going on by tomorrow morning.