Texas winter wx thread (2009-2010)

[snow and ice]

I don't believe the 0z GFS and 0z Euro can be in better agreement. Below are both models depiction of the 500mb flow at 168 hours (Christmas Day). Cold for Texas? You better believe it! Probably 15-20 degrees BELOW NORMAL. Snow or ice? Uh, not looking too good for that.

The 0z GFS



The 0z Euro

Looks very chilly for Christmas Day. Things begin to get interesting in the period between Christmas and New Years Day though. With very a cold air mass in place and an active N/NW Flow Aloft with reinforcing surges of much colder air as well as a noisy SJT, the stage is being set for what appears to be 'active' period. Add to the mix any embedded shortwave activity that cannot be forecast at this range in the Upper N/NW flow as well as a surface Low developing yet again in the NW GOM, the stage may be set for some wintry weather for many across TX and the S Plains. Stay Tuned.

That's what a lot of people are failing to realize. You need the cold air in place ahead of the storm, not behind the storm like the one next week. The mid-late week cold front will set the table, a long with reinforcing shots, for winter weather the next couple weeks. BTW, the 0z GFS took away everyone's white Christmas on the east coast.

[snow and ice]

To say the 0z EURO is dumping the very cold air straight down the plains would be an understatement. It's also no longer showing the east coast storm for next week. The people at accuweather will be doing a 180 today as they were advertising a major east coast storm for Christmas week.

0z EURO:
http://www.ecmwf.int/products/forecasts ... 9121800!!/

[gofrogs]

Is that good or bad for us

[srainhoutx]

If the 00z EC and GFS is correct, there will be a lot of back side (wrap around) moisture falling in a very cold Upper Air mass. Surface temps will not be an issue at all. We are expecting temps to be in the mid 20's or lower Christmas morning in SE TX. The thing to watch for is embedded Upper Air disturances rotating in behind the pre Christmas Arctic Front in the N/NW flow. Those features are impossible to forecast this far out. With that said, the stage is set for many in TX to see some wintry weather. We shall see

[HockeyTx82]

For what it's worth check out the 28th - 30th. Cold temps with precip........................ Hmmmmmm..............

http://wxweb.meteostar.com/sample/sampl ... ?text=kftw

[iorange55]

For what it's worth check out the 28th - 30th. Cold temps with precip........................ Hmmmmmm..............

http://wxweb.meteostar.com/sample/sampl ... ?text=kftw

Looks like it could be an ice storm if that happened

[srainhoutx]

For what it's worth check out the 28th - 30th. Cold temps with precip........................ Hmmmmmm..............

http://wxweb.meteostar.com/sample/sampl ... ?text=kftw

Looks like it could be an ice storm if that happened

Verbatim, yes. Those plots you see in the 500-1000mb thickness are based off the GFS. That is a long way out for any guidance to be accurate with the 'finer' details beyond 96 hours or so. The pattern overall looks very good with a deep trough from the Inter Mountain West to the East Coast. If you will notice, the 200mb and 300mb charts suggest a very deep trough across TX. Those will need to be watched carefully as well as the 500mb for "hints" of shortwaves in the Upper flow.

[msstateguy83]

i havent looked at the 12z yet just came out, but remember you guys we are talking RUN TO RUN, rightnow
just becouse one run says one thing does not mean its gonna happen.. like the 12z might be totally diffrent
again from the overnight run, when we get closer to monday is when the picture should start becoming more
clear what in reality is going to happen.

[Ntxw]

Well, the Christmas storm has officially gone too far north as of now, which lines up with the EC pretty well. Cold though

[mysterymachinebl]

Well, the Christmas storm has officially gone too far north as of now, which lines up with the EC pretty well. Cold though

Well, if there can't be snow, at least it should be quite chilly, which is good enough for me! I've been quite happy with the cold weather we've been having as opposed to the past few years!

[Big O]

In the North Texas Winter topic, CaptinCrunch wrote:

"Well the cold is coming and when it gets here it's sticking around for awhile. Timing of the arctic airmass is later than expecting and looks to be in here Christmas Eve or early Christmas Day, with highs hoovering around the freezing mark and lows in the lower 20's. The weekend looks to be slightly colder with highs in the upper 20's and may even see teens for lows. Several arctic fronts will drop down over the week through New Years and yes the chance for winter precip is still there but more for the new year.

Several waves will swind around the upper high and we could see a few flurries Christmas day and night, but better chance of something by Tuesday 29th. The upper air patteren favors a stormy January with arctic intrusions."

My questions are as follows:

1. Which models and/or indices are showing wintery precipitation in the new year?

2. What about 12/29? What are you relying on for snow on this date? Is this strictly for north Texas?

3. What pattern are you referring to that favors a stormy January with arctic intrusions? Do you really think the pattern we are in is going to lock in through January? How long into January? It's my understanding that the NAO is going to go neutral to positive in early January? Not sure about the AO, EPO, or PNA.

Any opinions are welcomed?

[Ntxw]

In the North Texas Winter topic, CaptinCrunch wrote:

"Well the cold is coming and when it gets here it's sticking around for awhile. Timing of the arctic airmass is later than expecting and looks to be in here Christmas Eve or early Christmas Day, with highs hoovering around the freezing mark and lows in the lower 20's. The weekend looks to be slightly colder with highs in the upper 20's and may even see teens for lows. Several arctic fronts will drop down over the week through New Years and yes the chance for winter precip is still there but more for the new year.

Several waves will swind around the upper high and we could see a few flurries Christmas day and night, but better chance of something by Tuesday 29th. The upper air patteren favors a stormy January with arctic intrusions."

My questions are as follows:

1. Which models and/or indices are showing wintery precipitation in the new year?

2. What about 12/29? What are you relying on for snow on this date? Is this strictly for north Texas?

3. What pattern are you referring to that favors a stormy January with arctic intrusions? Do you really think the pattern we are in is going to lock in through January? How long into January? It's my understanding that the NAO is going to go neutral to positive in early January? Not sure about the AO, EPO, or PNA.

Any opinions are welcomed?

Several runs ago, the gfs did depict this scenario, however the latest runs have gradually evened out with the EC which at this time doesn't show much with precipitation. Cold is there however.

[HockeyTx82]

Are we talking cold for the whole state or just the northern half? As we all know Texas is a big state and I am not sure where everyone is when they post about the weather in there area.

[srainhoutx]

FYI: The CPC Super Ensembles have suggested that the strong -NAO will relax for a few days, to only reload and go back to a stronly negative state, hence the "wash, rinse and repeat" pattern we are seeing in the Longer Range.

[HockeyTx82]

FYI: The CPC Super Ensembles have suggested that the strong -NAO will relax for a few days, to only reload and go back to a stronly negative state, hence the "wash, rinse and repeat" pattern we are seeing in the Longer Range.

So in other words we are going to have a real winter this year? I am not sure what -NAO and the information after means, but I am guessing cold with more cold?

[srainhoutx]

FYI: The CPC Super Ensembles have suggested that the strong -NAO will relax for a few days, to only reload and go back to a stronly negative state, hence the "wash, rinse and repeat" pattern we are seeing in the Longer Range.

So in other words we are going to have a real winter this year? I am not sure what -NAO and the information after means, but I am guessing cold with more cold?

Basically yes. A point I will make, and certainly one of our "pros" can correct me if I'm wrong, is the Model Guidance from systems not onshore or near a surface observation station (like Corpus Christi and Lake Charles for us in Houston are launched) are derived from Satellite Data that does not pick all of the actual dynamic nuances with any given disturbance. The actual data that is derived from RAOBS (Radiosonde Observation/Upper-Air Sampling) is entered into the data set once the systems are onshore. Just some food for thought.

[srainhoutx]

Alright folks. I have to run for now, but the 12Z ECMWF as well as the CMC will likely start some conversation back in the thread again.

[Big O]

FYI: The CPC Super Ensembles have suggested that the strong -NAO will relax for a few days, to only reload and go back to a stronly negative state, hence the "wash, rinse and repeat" pattern we are seeing in the Longer Range.

That is true, but the core of the cold is centered over the eastern US. Moreover, the pattern depicted is for December 28, not for January.

A question I have is do we really want a -NAO? Does anyone know what the various indicies were during our record cold snaps in 1983 and 1989 (i.e., AO, NAO, EPO, PNA)? In what state would the various indicies have to be in to induce a McFarlane (sic?) signature?

[Ntxw]

Wow the 12z EC...I sure hope it's reputation as a trend setter is in fruition! Not all is lost

[Portastorm]

Alright folks. I have to run for now, but the 12Z ECMWF as well as the CMC will likely start some conversation back in the thread again.

I'm trying hard not to say much ... but for those who haven't seen those runs yet, the Arctic front around Christmas looks "wetter" -- before AND after -- on these runs than previous runs. But, we gotta keep in mind it is just one run. If these solutions are showing up Sunday and Monday ... then it'll be time to buy those ice scrapers and snowplows. Heh, heh.