Texas Winter 2010-2011

[Air Force Met]

18Z NAM coming in much more wet...and moist. RH levels at 700MB are much higher and NAM now showing snow over SE TX and LA by Thursday afternoon. Predicted radar really lighting up on the coast by 48 hrs...and by 00Z Friday (Thursday evening)...NAM showing 1" snow depths already. This is a huge change.

Much of the moisture seems to be much further east though . It looks like it is trending with the GFS.

I don't see that at all. There is much more snow cover and qpf...everywhere. Now..the heaviest stuff is trending further east...into E Tx and Cntl LA...but its expanding SW every model run.

Here is a ball-park guess of the diff b/w the 12z run and the 18z (in inches of snow cover):

CITY: 12Z RUN / 18Z RUN
Bay City: T / 1
CLL: T / .5-1
AUS: T / T
LFK: .5 / 2
HOU: 1 / 2.5
IAH: .75 / 2.5
GLS: 1 / 2.5-3
LBX: 1 / 2.25
BPT: 2-2.5 / 4
JASPER: 2 / 4
FT POLK: 4 / 4

So...lots of snow being forecasted by the NAM. If THIS forecast were to verify...you can assume there will be bands of 6-8" within the 4" area...and bands of 4-6" in the 2" area.

[downsouthman1]

18Z NAM coming in much more wet...and moist. RH levels at 700MB are much higher and NAM now showing snow over SE TX and LA by Thursday afternoon. Predicted radar really lighting up on the coast by 48 hrs...and by 00Z Friday (Thursday evening)...NAM showing 1" snow depths already. This is a huge change.

Much of the moisture seems to be much further east though . It looks like it is trending with the GFS.

I don't see that at all. There is much more snow cover and qpf...everywhere. Now..the heaviest stuff is trending further east...into E Tx and Cntl LA...but its expanding SW every model run.

Here is a ball-park guess of the diff b/w the 12z run and the 18z (in inches of snow cover):

CITY: 12Z RUN / 18Z RUN
Bay City: T / 1
CLL: T / .5-1
AUS: T / T
LFK: .5 / 2
HOU: 1 / 2.5
IAH: .75 / 2.5
GLS: 1 / 2.5-3
LBX: 1 / 2.25
BPT: 2-2.5 / 4
JASPER: 2 / 4
FT POLK: 4 / 4

So...lots of snow being forecasted by the NAM. If THIS forecast were to verify...you can assume there will be bands of 6-8" within the 4" area...and bands of 4-6" in the 2" area.

The one thing I think the models aren't seeing right now is a certain pattern I've noticed by looking at water vapor loops over the past month, & based on my inference, I would say that the storm will develop at the base of the trough & cause more wintry precip further west of where it shows it beginning. The pattern I'm referring to is the same pattern that caused the snow in the southeast & numerous nor'easters is currently causing ARKLATEX/OK snows & then the system will move up to like MI, IN, IL, MO, OH, & parts of KY & TN. Thus spreading the more significant winter precip further west. So the nor'easters should be done for now because the pattern is shifted west.

Not an official forecast!

[South Texas Storms]

18Z NAM coming in much more wet...and moist. RH levels at 700MB are much higher and NAM now showing snow over SE TX and LA by Thursday afternoon. Predicted radar really lighting up on the coast by 48 hrs...and by 00Z Friday (Thursday evening)...NAM showing 1" snow depths already. This is a huge change.

Much of the moisture seems to be much further east though . It looks like it is trending with the GFS.

I don't see that at all. There is much more snow cover and qpf...everywhere. Now..the heaviest stuff is trending further east...into E Tx and Cntl LA...but its expanding SW every model run.

Here is a ball-park guess of the diff b/w the 12z run and the 18z (in inches of snow cover):

CITY: 12Z RUN / 18Z RUN
Bay City: T / 1
CLL: T / .5-1
AUS: T / T
LFK: .5 / 2
HOU: 1 / 2.5
IAH: .75 / 2.5
GLS: 1 / 2.5-3
LBX: 1 / 2.25
BPT: 2-2.5 / 4
JASPER: 2 / 4
FT POLK: 4 / 4

So...lots of snow being forecasted by the NAM. If THIS forecast were to verify...you can assume there will be bands of 6-8" within the 4" area...and bands of 4-6" in the 2" area.

AFM, do you expect this trend of the snow to gradually continue to shift SW with each model run until the event?

[Portastorm]

Thanks to a former S2K member (aggiecutter), I now have some hope for snow in our area ... so, those of you fellow Austinites and downsouthman1 up in Killeen, take heart. The 12z GFS ensembles do, for the most part, support a lot more qpf/snow for us than the operational run.

http://www.meteo.psu.edu/~gadomski/ENSPRS_12z/f72.html

So we need to hope on these ensembles as well as the Canadian. It's a small flame ... but it hasn't been snuffed out yet!

[TeamPlayersBlue]

Well the trend towards more moisture is very positive. Now we need to pinpoint where the moisture and storm shall be!

[South Texas Storms]

Thanks to a former S2K member (aggiecutter), I now have some hope for snow in our area ... so, those of you fellow Austinites and downsouthman1 up in Killeen, take heart. The 12z GFS ensembles do, for the most part, support a lot more qpf/snow for us than the operational run.

http://www.meteo.psu.edu/~gadomski/ENSPRS_12z/f72.html

So we need to hope on these ensembles as well as the Canadian. It's a small flame ... but it hasn't been snuffed out yet!

Good news Portastorm! Let's hope all the models trend to the GFS ensembles and Canadian so that we can have a snow parade on Friday!

[Ntxw]

The one thing I think the models aren't seeing right now is a certain pattern I've noticed by looking at water vapor loops over the past month, & based on my inference, I would say that the storm will develop at the base of the trough & cause more wintry precip further west of where it shows it beginning. The pattern I'm referring to is the same pattern that caused the snow in the southeast & numerous nor'easters is currently causing ARKLATEX/OK snows & then the system will move up to like MI, IN, IL, MO, OH, & parts of KY & TN. Thus spreading the more significant winter precip further west. So the nor'easters should be done for now because the pattern is shifted west.

Not an official forecast!

NAO is no longer negative and the +PNA (trough in the middle of the country) and a southeast ridge (small one) so far. PNA is going negative so middle of the month should switch for a time warmer east, colder west. But then again, when has this winter listened?

[Air Force Met]

AFM, do you expect this trend of the snow to gradually continue to shift SW with each model run until the event?

I do. If anything, I expect the models to trend towards the CMC/Euro solutions rather than vice versa. Now...there may be some shifts back to drier...but the overall trend should be wetter. The dpts behind this front are nto bone dry. Even up in the panhandle there is only a 10 deg dpt depression. the trof is very strong...and with the flow coming off the pacific for so long...it can't help but pick up moisture. I am a little surprised to see the NAM starting the snow thursday afternoon now...but that is how much wetter this run was than the last. As I said...BIG difference and it starts the precip sooner...which is what the CMC does.

[cctxhurricanewatcher]

Any of you want to take a stab in the dark on how much frozen precip the Corpus Christi area might (if any) get?

[jasons2k]

Everything is wrapped and ready to go here. We dipped to about 32-33F for a brief bit but we've been at 35-36 for a few hours now.

I think this will be the final stake for a lot of my plants. I say bring on the snow and I'll plant a more cold-hardy garden!

[Ntxw]

Thanks to a former S2K member (aggiecutter), I now have some hope for snow in our area ... so, those of you fellow Austinites and downsouthman1 up in Killeen, take heart. The 12z GFS ensembles do, for the most part, support a lot more qpf/snow for us than the operational run.

http://www.meteo.psu.edu/~gadomski/ENSPRS_12z/f72.html

So we need to hope on these ensembles as well as the Canadian. It's a small flame ... but it hasn't been snuffed out yet!

Some SREF members also suggest the upper low itself will be vigorous enough to generate some precip

[Rgv20]

Interesting that the 12z GFS Ensembles are colder and wetter than the operational GFS for thursday in south texas....Perhaps some snow in the offering??

[BrokenGlass]

FTW AFD still only discussion through tonight. Current forecast there still show 20% chance of snow Thurs evening and Friday.

Area forecast discussion
National Weather Service Fort Worth Texas
1219 PM CST Tuesday Feb 1 2011


Update...
cold advection is strong and deep enough that it has caused nearly
adiabatic lapse rates in the first 3000 feet. Moisture is still
sufficient for weak convective snow showers...which are being
forced by horizontal convective rolls as seen on radar. Have added
scattered light snow showers to most of the County Warning Area...but minimal new
accumulations are expected. These convective clouds should
dissipate with sunset and leave much of the area with mostly clear
skies. Have lowered overnight lows tonight based on temperatures
upstream...strong cold advection continuing...and the few degrees
that will be lost to radiational cooling. This should result in
min temperatures well into the single digits across the northwest half of the
area...and low teens elsewhere. Due to the extreme cold and danger
to exposed pipes...a hard freeze warning has been issued. Tr.92


&&

[Portastorm]

Thanks to a former S2K member (aggiecutter), I now have some hope for snow in our area ... so, those of you fellow Austinites and downsouthman1 up in Killeen, take heart. The 12z GFS ensembles do, for the most part, support a lot more qpf/snow for us than the operational run.

http://www.meteo.psu.edu/~gadomski/ENSPRS_12z/f72.html

So we need to hope on these ensembles as well as the Canadian. It's a small flame ... but it hasn't been snuffed out yet!

Some SREF members also suggest the upper low itself will be vigorous enough to generate some precip

At this point Ntxw, I'll take anything I can get.

[South Texas Storms]

AFM, do you expect this trend of the snow to gradually continue to shift SW with each model run until the event?

I do. If anything, I expect the models to trend towards the CMC/Euro solutions rather than vice versa. Now...there may be some shifts back to drier...but the overall trend should be wetter. The dpts behind this front are nto bone dry. Even up in the panhandle there is only a 10 deg dpt depression. the trof is very strong...and with the flow coming off the pacific for so long...it can't help but pick up moisture. I am a little surprised to see the NAM starting the snow thursday afternoon now...but that is how much wetter this run was than the last. As I said...BIG difference and it starts the precip sooner...which is what the CMC does.

Yay! Thanks AFM! That's what I wanted to hear! Hopefully both SA and Austin can get some snow too. I would love for my sisters back at home in San Antonio to be able to see it for the first time.

[Ntxw]

I don't want to overhype this or anything but signals are just getting too strong. North Texas/Oklahoma is frozen, Houston is going to get snow and the potential true 'motherload' of cold air is lurking for early next week while everyone is still freezing their bums off. Is this not reminiscent of 1899 or what? Of course not that cold, but something else is at play here.

[Ptarmigan]

Temperature Comparisons for Superbowl fans:
Dallas - |011853|19.9F|10.9F|67.5%|330|022|037|30.14|999|OVC|Light Snow

Green Bay - |011853|19.9F|14.0F|77.3%|030|019|025|30.40|999|OVC|Light Snow

Pittsburgh - |011903|35.0F|32.0F|86.6%|360|005|000|29.99|999|OVC|Light Drizzle , Mist

Looks like Dallas pulled out the red carpet to make both teams feel like they are at home. Kind of hot at Pittsburgh, though.

Green Bay and Dallas are the same temperature. Pittsburgh is warmer and that place is cold.

[orangeblood]

Another note: that 500 mb chart for the Thursday system looks really good for a storm across Texas once again but where are we going to find the moisture ?

Two places...1st place is that huge body of water known as the Pacific. 700mb flow will be sucking in Pacific moisture...moistening up the column. 2nd place is the Gulf. The low will throw plenty of moisture in.

This is very similar to Christmas 2004...but perhaps with a little more moisture available...and colder temps (so a higher ratio).

It appears this upper low won't dig as far south thus causing less moisture to be pulled up from the gulf. If you want a 2004 storm, that storm needs to dig much further south.

[South Texas Storms]

18z GFS starting to update! I hope it continues the trend of more snow for Central/SE Texas!

[Air Force Met]

It appears this upper low won't dig as far south thus causing less moisture to be pulled up from the gulf. If you want a 2004 storm, that storm needs to dig much further south.

That is incorrect.

The 2004 storm had the 300 DM line down just to the Red River of TX/OK. It ran from about a Perryton-CD-SPS-TXK line. The 320 DM line ran from the extreme corner of SE NM to about 50 miles N of Del Rio to Longview. The 330 line was down into Mex.

This storm has the 300 DM line along the west Tx/E NM borde - to the big bend of TX...south of Del Rio - to CLL to GGG. The 320 line is ovr west tx...into Mex...to Houston.

Another diff is the 700Mb moisture. The 2004 storm had the 90% RH's (precip threshold) just along the coast...this system has 90% over the eastern 1/3 of TX.

This is a stronger shotwave than 2004 (for example...heights over San Angelo will be 45 meters LOWER in this system than 2004)...it diggs much further south...and there is much more moisture progged.