Texas winter wx thread (2009-2010)

[srainhoutx]

I'll post the morning e-mail from Jeff in this thread as well since it has some importance to those beyond SE TX...

Very fast upper level flow will keep changes in the forecast about every 2-3 days.



Arctic boundary entering our central counties this morning and will be moving off the coast after sunrise. Strong cold air advection will onset and even under clearing skies, temperatures will struggle in the 50’s most of the day and even the upper 40’s over our northern counties given upstream air mass over the TX panhandle in the 10’s and 1’s. Clear skies and light winds tonight will result in a freeze are most locations…however last Saturday was our killing freeze and no advisories will be needed. Temperatures may not bottom out as cold as they could get given increasing high level cirrus late tonight.



Next strong short wave in this fast southern branch flow arrives into TX Friday with deepening coastal low formation over the NW Gulf of Mexico with extensive isentropic lift above the cold dome at the surface. Expect clouds to rapidly increase Thursday evening and then lower Thursday night as light rain breaks out as the now dry low level saturate. Expect widespread rains on Friday as the coastal low moves up the coast producing strong lift. Strong long fetch ENE winds will also raise tide levels along the upper Texas coast and do expect some issues at the same locations that have had several issues this fall…starting to sound like a broken record with these coastal low events! This go around temperatures, while cold, will be well above freezing and all the precipitation will fall as liquid…it is hard to believe but snow is still rare in these parts!


This system passes on quickly east by Friday evening with dry weather Saturday before the next fast moving short wave arrives early next week. Polar jet buckles with continued indications of a 1045mb+ high nosing into the northern high plains. Will onset strong isentropic processes late Sunday as yet another NW Gulf coastal low develops…this looks to be the breeding ground for a potentially intense Nor’ easter next week over the east coast and the key to helping drive the building arctic dome over the northern plains southward. Expect wet conditions Monday and Tuesday followed by a strong arctic air intrusion into TX. Will keep the coldest air NE of the state with the heart of the high headed more toward the Great Lakes and not due south…however such cold and dense air masses tend to drop southward faster than models show and tend to be colder. GFS has a high of 67 on Tuesday and 61 next Wednesday…will undercut these numbers by at least 10 degrees especially on Wednesday and that may not be cold enough. All rainfall should be east of the area prior to the onset of the cold air so once again everything should be liquid although an earlier arrival of the cold could result in freezing rain to our north.



Pattern looks cold and stormy leading up to Christmas and numerous short waves transverse the southern branch with multiple shots of cold arctic air in a favorable pattern for delivery. GFS is keying in on the 21-25 for a fairly significant cold air outbreak with lots of sub-tropical moisture and disturbances…could see several winter weather events across TX.

[CaptinCrunch]

I'll post the morning e-mail from Jeff in this thread as well since it has some importance to those beyond SE TX...

Very fast upper level flow will keep changes in the forecast about every 2-3 days.



Arctic boundary entering our central counties this morning and will be moving off the coast after sunrise. Strong cold air advection will onset and even under clearing skies, temperatures will struggle in the 50’s most of the day and even the upper 40’s over our northern counties given upstream air mass over the TX panhandle in the 10’s and 1’s. Clear skies and light winds tonight will result in a freeze are most locations…however last Saturday was our killing freeze and no advisories will be needed. Temperatures may not bottom out as cold as they could get given increasing high level cirrus late tonight.



Next strong short wave in this fast southern branch flow arrives into TX Friday with deepening coastal low formation over the NW Gulf of Mexico with extensive isentropic lift above the cold dome at the surface. Expect clouds to rapidly increase Thursday evening and then lower Thursday night as light rain breaks out as the now dry low level saturate. Expect widespread rains on Friday as the coastal low moves up the coast producing strong lift. Strong long fetch ENE winds will also raise tide levels along the upper Texas coast and do expect some issues at the same locations that have had several issues this fall…starting to sound like a broken record with these coastal low events! This go around temperatures, while cold, will be well above freezing and all the precipitation will fall as liquid…it is hard to believe but snow is still rare in these parts!


This system passes on quickly east by Friday evening with dry weather Saturday before the next fast moving short wave arrives early next week. Polar jet buckles with continued indications of a 1045mb+ high nosing into the northern high plains. Will onset strong isentropic processes late Sunday as yet another NW Gulf coastal low develops…this looks to be the breeding ground for a potentially intense Nor’ easter next week over the east coast and the key to helping drive the building arctic dome over the northern plains southward. Expect wet conditions Monday and Tuesday followed by a strong arctic air intrusion into TX. Will keep the coldest air NE of the state with the heart of the high headed more toward the Great Lakes and not due south…however such cold and dense air masses tend to drop southward faster than models show and tend to be colder. GFS has a high of 67 on Tuesday and 61 next Wednesday…will undercut these numbers by at least 10 degrees especially on Wednesday and that may not be cold enough. All rainfall should be east of the area prior to the onset of the cold air so once again everything should be liquid although an earlier arrival of the cold could result in freezing rain to our north.



Pattern looks cold and stormy leading up to Christmas and numerous short waves transverse the southern branch with multiple shots of cold arctic air in a favorable pattern for delivery. GFS is keying in on the 21-25 for a fairly significant cold air outbreak with lots of sub-tropical moisture and disturbances…could see several winter weather events across TX.

As I stated yesterday in my Winter Outlook, that around Dec 20th a major change is coming and a white Christmas could be in the works for NTX, I got a Dec 22-23 date for a major winter event happing for much of NTX.

[srainhoutx]

Yeah CaptinCrunch. I think many of us that enjoy the Long Range stuff have seen a lot of potential around the 20th. MJO in Phase 5 back on November 22nd was a nice "hint". Looks like we are on track and add the noisy STJ and we're in business. Trends are looking good.

[snow and ice]

The long range Ensembles look very cold for latter December, blocking across the top with a west coast ridge and southern plains-eastern trough.

6z Ensembles:
http://www.meteo.psu.edu/~gadomski/ENSH ... /f288.html

[cctxhurricanewatcher]

Larry Cosgrove had some interesting thoughts tonight..

Since strong blocking signals will exist in three critical positions (+PNA, -AO, -NAO), this particular cold front will carry with it the same change seen late last week. The computer models drive the leading edge of the frigid blast into southern Mexico (no, I am NOT kidding...even Cuba will get into the colder air!). Cyclogenesis may occur twice over the western Gulf of Mexico between December 15 and 24 as subtropical jet stream energy interacts with the uplift created by cold values sliding over the warm water. Both storms may drag the tundra motherlode into the Great Lakes and Northeast, which can only mean intense cold in two spells before Christmas Eve.

And I might add that I will not rule out another (rare) frozen precipitation event for Houston later this month.

This is shaping up to be an interesting winter....

I'll add the La La Land 06Z GFS for grins just in time for Christmas...do I hear a little Bing Crosby music in the background SG?...

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_384l.gif

We would need some snow removal equipment in Corpus and Brownsville for sure!

[gboudx]

I got a Dec 22-23 date for a major winter event happing for much of NTX.

Could you push that to Dec 23/24? Much appreciated.

[CaptinCrunch]

I got a Dec 22-23 date for a major winter event happing for much of NTX.

Could you push that to Dec 23/24? Much appreciated.

I would love a 23-25 event, but time will tell.

[wxgirl69]

December 20 is still a long way away... I hope we get some cold.. I am not going to get excited yet..
Are the models showing a pattern of cold air coming down, or is still all over the place.

[Portastorm]

December 20 is still a long way away... I hope we get some cold.. I am not going to get excited yet..
Are the models showing a pattern of cold air coming down, or is still all over the place.

The short answer wxgirl69 is yes, the models are showing cold air coming down into Texas by the middle of next week ... although we have some cold air RIGHT NOW over us!

What till y'all see the 12z GFS run which I just peeked at. Oh my! Heart be still ...

[srainhoutx]

What till y'all see the 12z GFS run which I just peeked at. Oh my! Heart be still ...

Hang on Portastorm, it's going to be a long 2-3 weeks.

[msstateguy83]

you talking about the new soon to be used gfs or currently used gfs? details,details iam busy this am
i want details now lol

[iorange55]

Holy if that came true next friday. It would mean once again north texas would only get light precip :[ but still wow.

[srainhoutx]

Current GFS...


Hour 216

http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_216l.gif

Parallel...

http://www.nco.ncep.noaa.gov/pmb/nwpara ... p_216l.gif

[Portastorm]

Current GFS...


Hour 216

http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_216l.gif

Parallel...

http://www.nco.ncep.noaa.gov/pmb/nwpara ... p_216l.gif

I'll take the current GFS for $20, please!

[Portastorm]

And BTW, today's Polar airmass is nothing to scoff out. With strong cold air advection (CAA) continuing, we're only at 35 degrees at 11 a.m. here in Austin and the sun has been shining bright all morning. Brrr!

[iorange55]

And BTW, today's Polar airmass is nothing to scoff out. With strong cold air advection (CAA) continuing, we're only at 35 degrees at 11 a.m. here in Austin and the sun has been shining bright all morning. Brrr!

No kidding we were at 50 around 8pm here in Dallas, and by 5am it was 23 with a strong wind.

[srainhoutx]

Point of interest in the 12Z GFS run is noting the 300mb winds and 500mb Vort Max seen around hour 174 and there after. Another Upper Air disturbance and some phasing as well. Now where have we seen that before. Although this run shows some warming behind this cold air into Christams, I wouldn't bet the ranch on it. All in all, the trends continue to look good for some nice "unmodified" Arctic Air and a noisy STJ.

[wxgirl69]

December 20 is still a long way away... I hope we get some cold.. I am not going to get excited yet..
Are the models showing a pattern of cold air coming down, or is still all over the place.

The short answer wxgirl69 is yes, the models are showing cold air coming down into Texas by the middle of next week ... although we have some cold air RIGHT NOW over us!

What till y'all see the 12z GFS run which I just peeked at. Oh my! Heart be still ...

ok... now you are getting me excited...

[rhoby13]

How accurate are these GFS models 9-14 days out?

[srainhoutx]

How accurate are these GFS models 9-14 days out?

The GFS nailed the 2004 event at this range. Also note the Parallel GFS @ 384 Hours...

http://www.nco.ncep.noaa.gov/pmb/nwpara ... n_384l.gif