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

[gboudx]

DFW update tonight.

AREA FORECAST DISCUSSION...UPDATE (CORRECTED WORDING 2ND PARA)
NATIONAL WEATHER SERVICE FORT WORTH TX
845 PM CST TUE DEC 19 2006

.UPDATE...
...
AS FOR THE UPCOMING WEEKEND STORM...ALTHOUGH WE DO NOT HAVE ANY NEW
DATA TO WORK WITH THIS EVENING...WE STILL HAVE SOME CONCERN FOR THE
TRACK OF THE UPPER LOW...HOW COLD IT WILL BE AND THE POTENTIAL FOR
WINTRY PRECIPITATION OVER THE WESTERN COUNTIES. AN EVALUATION OF
EARLIER MODELS RUNS SHOWS THIS POTENTIAL NEARING I-35 ON SUNDAY
MORNING. IF THE UPPER SYSTEM TRACKS FURTHER SOUTH ALONG I-10...THEN
OUR FAR SOUTHWEST COUNTIES WILL BE AT RISK. IF IT TRACKS 100 MILES
FURTHER NORTH...ALONG A SAN ANGELO TO ATHENS LINE...THEN OUR ENTIRE
WESTERN CWA COULD SEE A SIGNIFICANT WINTER PRECIPITATION. DUE
TO MODEL INCONSISTENCY OVER THE PAST SEVERAL DAYS...WE HAVE NOT
DECIDED TO ADD WINTRY PRECIPITATION TO THE FORECAST AT THIS TIME.

[aggiecutter]

By Friday, the models should have a good handle on what is going to happen. There will still be a lot of model run to run discrepancy the next 48 hours. I will say this, the one trend that I have seen the past 48 hours is that the models, at least the GFS, wants to take the upper level system on a Northeastern track from the Big Bend area to NE Texas-NW Louisiana. Looks like a real headache for forecasters late this weekend into early next week as temperatures will be marginal for winter precipitation. A long the path of the upper level system, you could get anything from light rain to heavy snow. That is how unpredictable systems like these are.

[Yankeegirl]

Like I said before, Bring it ON!!!

[Portastorm]

After my Wednesday morning perusal of the GFS runs and the Euro ... I'm thinking that unless you're just north of the eventual track of the upper low this weekend ... you'll be getting nothing more than a meteorological lump of coal. The air profiles seem too warm to support any kind of decent outbreak of snow/ice unless you're in the path of this system.

The GFS is trending a move more to the northeast (as aggiecutter pointed out in an earlier post) for the system ... Big Bend to Tyler. The 0z Euro actually moves it southeast from the Big Bend area to down near Victoria.

I have growing doubts that this will amount to much of anything for us in the Austin area. Sorry ... but as of now, that's how I see it. However, I won't get too excited about any model scenario until Friday morning.

Meanwhile, I'm about to trek back up Mt. Bastardi to see what the wise one has to offer.

[double D]

I agree Portastorm, I don't think we will see much out of this at all. In fact, the gfs has been showing less QPF for our area than previous runs. I wouldn't be surprised if a few places got some light snow, but I don't see any major problems for anyone in Texas.....at least right now anyway.

Oh well, at least this pattern favors some future snow/ice events in Texas.

[aggiecutter]

Hey Portastorm, It looks like the GFS has picked on your Guru's early-mid month cold spell. Checkout that 1056mb monster in NW Canada.

GFS 6Z:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _384.shtml

[Burn1]

That looks like some cold days early in the year for the folks in Florida!

[Extremeweatherguy]

hmm.. this is interesting.

The 12z GFS is now showing a stronger high coming down the plains with this system (1040mb) than in earlier runs.

Here is the comparison:

12z at 72hrs. = http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_072l.gif
^^1040mb^^

6z at 78hrs. = http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_078l.gif
^^1036mb^^

0z at 84hrs. = http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_084l.gif
^^1036mb^^

I wonder how this could affect the end result of the situation?

[Extremeweatherguy]

The strangest thing is that even with the stronger high, the 12z is showing a warmer situation with less cold air. This is probably due to the fast movement of the low it is showing (and showing it be well offshore). If the low is slower, however, then I think this has major potential. The main questions from a few days ago seem to still be in place..

-How cold will it be?

-How cold will the upper levels be?

-How much moisture will there be to work with?

-where will the weather systems be (lows and highs and fronts)?

-What will the speeds of the weather systems be?

Hopefully we will have answers to these questions soon...

[CaptinCrunch]

The Akron, CO forecast....those lucky doggs!!

Today: Periods of snow with widespread blowing snow. The snow could be heavy at times. High near 29. Blustery, with a north northeast wind between 23 and 28 mph, with gusts as high as 41 mph. Chance of precipitation is 100%. Total daytime snow accumulation of 6 to 10 inches possible.

Tonight: Periods of snow with widespread blowing snow. The snow could be heavy at times. Low around 17. Blustery, with a north northwest wind between 23 and 29 mph, with gusts as high as 44 mph. Chance of precipitation is 100%. New snow accumulation of 4 to 8 inches possible.

Thursday: Snow showers likely with areas of blowing snow, mainly before noon. Cloudy, then gradually becoming partly sunny, with a high near 28. Wind chill values between -1 and 9. Blustery, with a north northwest wind between 14 and 23 mph, with gusts as high as 28 mph. Chance of precipitation is 70%. New snow accumulation of 2 to 4 inches possible.

[gboudx]

Man, I think 12" of snow would cripple DFW for a few days.

[double D]

The strangest thing is that even with the stronger high, the 12z is showing a warmer situation with less cold air. This is probably due to the fast movement of the low it is showing (and showing it be well offshore). If the low is slower, however, then I think this has major potential. The main questions from a few days ago seem to still be in place..

-How cold will it be?

-How cold will the upper levels be?

-How much moisture will there be to work with?

-where will the weather systems be (lows and highs and fronts)?

-What will the speeds of the weather systems be?

Hopefully we will have answers to these questions soon...

Especially with a pretty decent snowpack up to our north and west. I don't see how the gfs would paint a warmer solution because the air would not modify as much.

I still don't think we will know the details until 24 hours out of the event. The gfs just has not performed well lately.

[Extremeweatherguy]

The strangest thing is that even with the stronger high, the 12z is showing a warmer situation with less cold air. This is probably due to the fast movement of the low it is showing (and showing it be well offshore). If the low is slower, however, then I think this has major potential. The main questions from a few days ago seem to still be in place..

-How cold will it be?

-How cold will the upper levels be?

-How much moisture will there be to work with?

-where will the weather systems be (lows and highs and fronts)?

-What will the speeds of the weather systems be?

Hopefully we will have answers to these questions soon...

Especially with a pretty decent snowpack up to our north and west. I don't see how the gfs would paint a warmer solution because the air would not modify as much.

I still don't think we will know the details until 24 hours out of the event. The gfs just has not performed well lately.

yeah, that's what i'm thinking too. That snowpack should be a dent in any warmer scenario.

[Portastorm]

The consensus that this weekend will NOT bring a winter weather event to much of Texas appears to be growing, unfortunately.

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1141 AM CST WED DEC 20 2006

.UPDATE...
QUICK UPDATE TO CONTINUE DROPPING POPS IN THE WEST AS PRECIP MOVES
EAST. HAVE LOOKED AT WEEKEND AGAIN...AND MODELS JUST DO NOT KEEP
ENOUGH MOISTURE OVER NORTH TEXAS FOR MORE THAN A SLIGHT CHANCE OF
PRECIP IN THE WEST AN SOUTH...SO HAVE LOWERED WEEKEND POPS. THIS IS
JUST NOT A WINTER OUTBREAK SCENARIO FOR OUR AREA. 84

[Extremeweatherguy]

The consensus that this weekend will NOT bring a winter weather event to much of Texas appears to be growing, unfortunately.

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1141 AM CST WED DEC 20 2006

.UPDATE...
QUICK UPDATE TO CONTINUE DROPPING POPS IN THE WEST AS PRECIP MOVES
EAST. HAVE LOOKED AT WEEKEND AGAIN...AND MODELS JUST DO NOT KEEP
ENOUGH MOISTURE OVER NORTH TEXAS FOR MORE THAN A SLIGHT CHANCE OF
PRECIP IN THE WEST AN SOUTH...SO HAVE LOWERED WEEKEND POPS. THIS IS
JUST NOT A WINTER OUTBREAK SCENARIO FOR OUR AREA. 84

let's just hope we are surprised.

Remember, a few days ago Denver was not expected to get too much snow for today and now they are being slammed by a blizzard and will probably be recieving feet of the white stuff. Shows how hard these events really are to forecast.

I do doubt we will see a major winter storm across TX though. However, I do think a few places could see some snow/sleet around the holiday, which is exciting.

[double D]

The consensus that this weekend will NOT bring a winter weather event to much of Texas appears to be growing, unfortunately.

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1141 AM CST WED DEC 20 2006

.UPDATE...
QUICK UPDATE TO CONTINUE DROPPING POPS IN THE WEST AS PRECIP MOVES
EAST. HAVE LOOKED AT WEEKEND AGAIN...AND MODELS JUST DO NOT KEEP
ENOUGH MOISTURE OVER NORTH TEXAS FOR MORE THAN A SLIGHT CHANCE OF
PRECIP IN THE WEST AN SOUTH...SO HAVE LOWERED WEEKEND POPS. THIS IS
JUST NOT A WINTER OUTBREAK SCENARIO FOR OUR AREA. 84

let's just hope we are surprised.

Remember, a few days ago Denver was not expected to get too much snow for today and now they are being slammed by a blizzard and will probably be recieving feet of the white stuff. Shows how hard these events really are to forecast.

I do doubt we will see a major winter storm across TX though. However, I do think a few places could see some snow/sleet around the holiday, which is exciting.

Not only moisture, but temps seem to be a problem for winter weather. With temps in the upper 40's also doesn't help our chances for winter weather. I was hoping that the gfs was going to trend towards a cooler solution but the opposite has happened. Only those lucky enough to be directly under the cold core of the low will likely see any snow and that is still a big IF.

Also unfortunately the gfs has backed off on a major cold blast for New Years (and snow) the last few runs, let's hope it will waffle back to the colder solution.

[Extremeweatherguy]

I question those temperatures though. If we do happen to have precipitation falling, then I doubt we will make it into the upper 40s. Evaporative cooling and CAA will likely keep us much cooler if precipitation is in fact falling. Either way though, most places will still likely be too warm for any siginificant winter weather.

The snowpack to our NW will be interesting though. Once the GFS picks up on that, I will be interested in seeing how it's scenario changes in the coming days. I still feel the GFS is not to be completely trusted until Friday (at least) though. Even minor changes could lead to major changes in the outcome. It has just been way to inconsistant lately.

[aggiecutter]

Portastorm, you mentioned that Bastardi stated there would be an arctic outbreak the first to middle of January because of upper level changes. Was the reason because the ridge went up east of the Caspian. When that happens, there is usually a two week lull before the arctic air hits the lower 48.

[southerngale]

[Portastorm]

Portastorm, you mentioned that Bastardi stated there would be an arctic outbreak the first to middle of January because of upper level changes. Was the reason because the ridge went up east the Caspian. When that happens, there is usually a two week lull before the arctic air hits the lower 48.

Isn't that the "Cahir's Connection" that you're talking about?

Well, JB hasn't mentioned that. He has referred to the 10mb upper low moving from our side of the pole to the north shore of Siberia ... which he says is often a precursor to Arctic outbreaks several weeks after the fact. He also referred to the large Aleutian low moving from Bering Straits to Gulf of Alaska.

And yes he has backed off on possibilities of a central Texas snow/ice event this weekend. On his video today, he still likes the idea of west Texas getting some action (like the Lubbock area down to San Angelo). Says the system will be moving too fast to create much havoc though.