Texas winter wx thread#5 - big changes on the way eventually

[southerngale]

Continue the TX winter discussion here.

Last thread: http://www.storm2k.org/phpbb2/viewtopic.php?t=91867

[southerngale]

wxman57 posted this on a Houston board and said it was ok to post here. He didn't realize we had a Texas thread in here talking about winter weather, so I invited him to join us.

Anyway, this is what he said on Thursday:

Posted: Thu Jan 04, 2007 11:09 am Post subject:

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Unfortunately, there is a major pattern change in the works that could bring some bitterly-cold Arctic air south into the U.S. for the last half of January. THe cold air over Siberia is migrating toward Alaska this week. As a ridge builds over the Gulf of Alaska next week, the Arctic air will be on the move southward. It's looking very stormy (snowy) for the Central Rockies through the Plains over the coming weeks. Possibly another big Colorado blizzard by the 12th-15th.. Beyond that time, the Arctic air may be reaching the Gulf coast and we may see frozen precip in Texas.

[jeff]

Battling the sea fog this evening along the coast with visibilities at or below 1.0 miles. Offshore platforms and vessels have been really locked in with less than 250 ft of visibility today. NEXRAD is showing increasing light showers over the area per latest sweeps as a result of the upper trough pushing into the area. Feel widespread light rains will occur tonight, but overall totals will be below 1/4th of an inch.

Seasonal weather on tap from Monday through Thursday with cold mornings (30-40's) and cool afternoons (50-60's). Warm up is in store for Thursday into Saturday and then the bottom falls out. Moisture return and increasing SW flow aloft will spell better rain chances Thursday peaking late Friday and early Saturday ahead of a major arctic front.

Extended:

Significant pattern amplification with potential major arctic air outbreak and nasty winter storm next weekend. Medium range guidance continues to show large scale ridging along the west coast building into Alaska and grabbing very cold arctic and Siberian air and surging it southward. Massive 1050mb to 1055mb arctic high pours out of the NW Territories and surges down the front range of the Rockies by late Thursday. Arctic boundary slows over OK Friday as surface low pressure develops over TX and then takes the final plunge through the state on the 14th. Dramatic temp. falls appear likely with temps. falling rapidly from the 60/70's into the 30/40's and then on below freezing. Arctic air mass looks very shallow in the guidance with 700mb temps. remaining above freezing, however the surface may be at or below freezing suggesting a potential icing event.

Will need to take a very close look at potential for an icing /ice storm /winter storm event across the state in the coming days. Models have been fairly consistent is producing a period of precip. behind the arctic boundary as the upper trough lags behind. Additionally, arctic air mass looks to lock into place and remain for several days with multiple reinforcing shots and per GFS many hours/days below freezing across the central and northern portion of the state.

El Nino winters can be quite nasty when arctic air comes in phase with an active southern branch jet...something we may see play out in the coming weeks.

[double D]

Very interesting write up Jeff. It has been a long time since we have experienced multiple days of below freezing in Central Texas. At this time where do you think the majority of the freezing rain would take place?

[jeff]

Very interesting write up Jeff. It has been a long time since we have experienced multiple days of below freezing in Central Texas. At this time where do you think the majority of the freezing rain would take place?

Hard to say this far out...but the models are likely too warm and maybe too slow with the arctic boundary as they tend to be in such situations. Feel central and north TX could very well see a significant ice/winter storm event...a little more questionable for points south and east (Houston). Looks mainly like a ZR or IP event given cold surfaces and warm nose then below freezing again higher up...maybe all ZR given large warm nose and shallow sub-freezing surface. Of course this is still days away and this winter has already proven that things forecast 7 days out will change...although I will say this looks like the best cold outbreak and winter weather potential since the 11/30 event.

[Ptarmigan]

I've notice before there is a freeze, there are periods of unusual warmth.

NOAA Climvis

[Portastorm]

OK folks, the 0z GFS run is cracked.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... /fpc.shtml

And no, I'm not saying this because it's showing a scenario that I don't like! In fact, it spins up a nice snowstorm for Austin on Jan. 19th ... and who wouldn't love that?!

My biggest problem with this run is that it basically meanders a low around the state of Texas all weekend and shows no arctic air impacting the state other than the Panhandle. That just seems implausible given what the Euro has consistently shown along with the NCEP ensembles for next weekend.

I don't think this run can be trusted much. Might as well throw out the 6z run, too, since it's based off the 0z run. Sheesh.

[Extremeweatherguy]

The 0z GFS continues the COLD look...


http://www.nco.ncep.noaa.gov/pmb/nwprod ... _192.shtml
^^Evening of Sunday the 14th. Cold air rushing south. Lots of snow/ice over central and northern parts of the state.^^

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _204.shtml
^^Morning of Monday the 15th. Some residual winter-type precip. showers across the state. Freeze line reaches all the way to the coast.^^

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _216.shtml
^^Evening of Monday the 15th. Temperatures below freezing for much of the state with freezing rain (and possibly sleet) developing over many areas of east and southeast Texas.^^

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _228.shtml
^^Morning of Tuesday the 16th. Pretty much the entire state of Texas is below freezing. Freezing rain (and possibly sleet) continues to fall in southeast and even south Texas!^^

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _240.shtml
^^Evening of Tuesday the 16th. Still cold everywhere (below freezing in most places). The freezing rain is slowly coming to an end.^^

Basically: If the 0z is correct then a major winter event looks likely starting next Sunday and lasting into the Tuesday after. It is even showing the potential for a major ice storm in SE Texas with highs likely below 35-degrees for many areas for at least 2 days. Could get VERY interesting if this plays out.

BTW, here are the actual 2-meter 0z GFS temps. for IAH during the time period shown above...

6pm Sunday the 14th = 39-degrees
6am Monday the 15th = 28-degrees
6pm Monday the 15th = 25.5-degrees
6am Tuesday the 16th = 25-degrees
6pm Tuesday the 16th = 27-degrees

[Extremeweatherguy]

OK folks, the 0z GFS run is cracked.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... /fpc.shtml

And no, I'm not saying this because it's showing a scenario that I don't like! In fact, it spins up a nice snowstorm for Austin on Jan. 19th ... and who wouldn't love that?!

My biggest problem with this run is that it basically meanders a low around the state of Texas all weekend and shows no arctic air impacting the state other than the Panhandle. That just seems implausible given what the Euro has consistently shown along with the NCEP ensembles for next weekend.

I don't think this run can be trusted much. Might as well throw out the 6z run, too, since it's based off the 0z run. Sheesh.

Actually, if you look at my post below (actually above now), the 0z GFS is still showing a VERY cold look. It may be cracked, but the arctic air is certainly still there on the latest run.

The reason it looks warm is because it is a very shallow airmass and the 850mb temps. are pretty warm. However, it is the surface temps. that will be cold. This means an ice storm is the most likely at this point (instead of snow). For a look at the surface temps, refer to the right column of the NCEP GFS page.

[Portastorm]

OK folks, the 0z GFS run is cracked.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... /fpc.shtml

And no, I'm not saying this because it's showing a scenario that I don't like! In fact, it spins up a nice snowstorm for Austin on Jan. 19th ... and who wouldn't love that?!

My biggest problem with this run is that it basically meanders a low around the state of Texas all weekend and shows no arctic air impacting the state other than the Panhandle. That just seems implausible given what the Euro has consistently shown along with the NCEP ensembles for next weekend.

I don't think this run can be trusted much. Might as well throw out the 6z run, too, since it's based off the 0z run. Sheesh.

Actually, if you look at my post below (actually above now), the 0z GFS is still showing a VERY cold look. It may be cracked, but the arctic air is certainly still there on the latest run.

EWG, I'm not saying it doesn't look cold. I'm saying it doesn't look cold early enough. I suspect the arctic air, albeit shallow, will be covering much more of the state by Sunday than this run shows.

Like aggiecutter has been saying ... it's a race between the developing low and the arctic air.

Once these arctic airmasses start coming down the lee side of the Rockies, it's "Katie, bar the door." We do have some snow cover, too, on that lee side so any "moderating" affects may be limited. I'm thinking the surface temps from Laredo to San Antonio to Tyler will be colder by Sunday than what we see on this run.

As for our weather after the 16th ... oh yeah, if this run were to verify, we'd all be partying Arctic style.

[cctxhurricanewatcher]

Portastorm,

We need the old timers from the Brownsvillle NWS to chime in.

[Johnny]

If freezing rain is the only possibility then y'all can have it. I traveled to the panhandle last weekend in search of snow and got caught up in some nasty icy roads caused by freezing rain. I'd rather have cold rain than freezing rain, that's for sure.

[aggiecutter]

I just looked at the 0z run of the GFS, and it has 78 written all over it. There are multiple shots of arctic air and 3-4 El Nino systems coming within the next 2 weeks, starting the beginning of next weekend. I think the one next weekend-early next week will be a moderate icing event(freezing rain) for the central and northern parts of the state as the low pulls out. It looks like the southern coastal areas will get a little icing from an overrunning setup as the arctic boundary stalls in the gulf.

However, beyond that, there is a strong likely hood that the northern and southern branch will phase, and Texas will see a major winter storm. This is as good as get for winter weather in the southern plains, so enjoy this setup for the next 2-4 weeks.

[Extremeweatherguy]

If freezing rain is the only possibility then y'all can have it. I traveled to the panhandle last weekend in search of snow and got caught up in some nasty icy roads caused by freezing rain. I'd rather have cold rain than freezing rain, that's for sure.

yeah, freezing rain is no fun, especially because it does more than just make roads slick. A good ice storm can also lead to power outages and tree/powerline damage. Being powerless in a freezing environment with branches falling through the roof cannot be a pleasant experience to go through.

I would much rather see a nice, calm 2-3" snowfall.

= BAD

= GOOD

Let's hope the models eventually trend more toward that good scenario.

[Yankeegirl]

My birthday is the 19th of Jan, would be awfully if you great people of Storm 2 K show me some love, since I have been a loyal member forever, and send me some snow!!!!

[aggiecutter]

The morning Ensembles continue to look very wintry for the southern plains. It looks like the pattern is going to lock in for atleast the next couple weeks.

Morning Ensembles 1-07:
http://www.cdc.noaa.gov/map/images/ens/ ... times.html

[double D]

FWIW the San Angelo NWS office wants to bring the front down next Friday instead of Sunday. They think the models are almost always to slow with these type of fronts.

Hopefully we will get more professional mets in here as the event draws near to give us an idea of which areas will see winter precip.

[Extremeweatherguy]

Latest from JB:

-He said that the period from Jan. 15th - Feb. 15th could be top 10 coldest 30 day stretch in 50 years!

-Abnormally high amounts of ice and snow should fall across the south and then east during this period.

-"number destroying" cold will work down into the plains later this week.

-Southern plains may get "real ugly" during the week of the 14th.

continues to look like this will be the real deal.

[Extremeweatherguy]

I know this is just some random weather site, but it is still interesting to look at:

http://weather.msn.com/tenday.aspx?weal ... c:USTX1290

The forecast for Spring, TX on the 15th is sleet with a high of 38-degrees and then on the 16th it shows PM snow with a low of 28-degrees. Though this is likely not an accurate forecast, it is always interesting to see one like this for a place where snow/ice is rare.

[wxman22]

Intellicast has the same thing

http://www.intellicast.com/IcastPage/Lo ... odnav=none