Texas Winter 2014-2015

[Ntxw]

Unless I'm mistaken the GFS has been switched to the new updates. Old GFS is now upgraded (think parallel).

[Portastorm]

Unless I'm mistaken the GFS has been switched to the new updates. Old GFS is now upgraded (think parallel).

Correct. The new GFS (the old parallel GFS) is switched as of today's 12z run which is rolling out now.

[cycloneye]

Unless I'm mistaken the GFS has been switched to the new updates. Old GFS is now upgraded (think parallel).

Correct. The new GFS (the old parallel GFS) is switched as of today's 12z run which is rolling out now.

Yes,GFS upgrade is underway.

[aggiecutter]

Unless I'm mistaken the GFS has been switched to the new updates. Old GFS is now upgraded (think parallel).

Correct. The new GFS (the old parallel GFS) is switched as of today's 12z run which is rolling out now.

Yes,GFS upgrade is underway.

I read yesterday where it will take a year before all the upgrades are fully implemented.

[TeamPlayersBlue]

GFS has a mean blizzard for the Panhandle and OK, and a nice looking Nor'Easter for New England.

This is for Thursday and Friday next week.

[Yukon Cornelius]

240 hours out, but still interesting.

[gboudx]

Unless I'm mistaken the GFS has been switched to the new updates. Old GFS is now upgraded (think parallel).

If you missed it, DFW had a good discussion about the new GFS and the use of MOS data for temp forecasting on a microscale.

/GFS MODEL UPGRADE/
AT 12Z TODAY A MAJOR UPGRADE TO THE GFS MODEL WILL OCCUR. THE
EFFECTIVE HORIZONTAL RESOLUTION WILL GO FROM 27 KM GRID SPACING TO
13 KM. IT WILL USE AN IMPROVED INITIALIZATION ANALYSIS...AND MANY
UPDATED PHYSIC SCHEMES...WHICH IN GENERAL ARE COMPUTATIONALLY MORE
INTENSIVE BUT ARE MORE ACCURATE. WE HAVE CASUALLY VIEWED THIS NEW
VERSION OF THE GFS OVER THE LAST FEW MONTHS WHICH WAS RUN IN
PARALLEL TO THE CURRENT VERSION. USUALLY THE TWO VERSIONS WERE
FAIRLY SIMILAR IN FORECAST...BUT THERE WERE MANY FORECAST EVENTS
THE NEW GFS PERFORMED BETTER.

THE UPGRADE IS CERTAINLY GOOD NEWS...BUT IT WILL COME AT SOME
COST TO THE GFS MOS WHICH FORECASTERS RELY HEAVILY ON TO PRODUCE
POINT SPECIFIC TEMPERATURE AND POP FORECASTS. MOS FORECASTS USE
STATISTICS AT SPECIFIC FORECAST POINTS TO CORRECT FOR SYSTEMATIC
BIASES IN THE RAW MODEL DATA. TO GIVE AN EASY EXAMPLE...AT A 27
KM RESOLUTION LOCAL TERRAIN FEATURES...LIKE A LARGE LAKE OR URBAN
AREA ARE STILL TOO SMALL TO SHOW UP IN THE MODEL GRID AND
THUS CANT BE REPRESENTED OR EXPLICITLY FORECAST FOR. SO AT A SITE
LIKE DFW WHICH SHOWS AN URBAN HEAT ISLAND EFFECT ON MOST NIGHTS...
THE RAW MODEL FORECAST MAY BE ON AVERAGE 4 DEGREES TOO COOL WITH
LOW TEMPS. THE MOS USES ERROR AND BIAS STATISTICS GATHERED OVER
YEARS TO CORRECT THE FORECAST...AND ALL THINGS CONSIDERED IT IS
REALLY GOOD AT IT. WHEN THE NEW HIGHER RESOLUTION MODEL COMES
ALONG...IT MAY NOW HAVE THE RESOLUTION TO SEE MORE OF THE URBAN
HEAT ISLAND AND THEREFORE DOES NOT NEED AS MUCH CORRECTING.
HOWEVER THE STATISTICS WE HAVE GLEANED FROM TRACKING THESE ERRORS
BECOME LESS USEFUL SINCE IT IS NOT CALIBRATED SO TO SPEAK TO THE
NEWER VERSION OF THE MODEL. THERE IS A NEW ERROR DATABASE GOING
FOR THE NEW GFS BUT IT IS ONLY A FEW MONTHS WORTH OF DATA AND IS
NOT NEARLY AS ROBUST. IN THEORY THE MOS WILL STILL BE PRETTY GOOD
DATA...BUT WE DO EXPECT IT TO PERFORM POORER THAN THE CURRENT MOS
WOULD HAVE FOR A WHILE. WE ARE TOLD BY THE MODEL DEVELOPERS THAT
THIS IS ESPECIALLY TRUE FOR THE 6Z AND 18Z MOS BULLETINS AND
THOSE SHOULD BE USED WITH CAUTION.

[Texas Snowman]

The winter of no snow but plenty of chilly temps and gray and gloomy skies continues. Cloudy and still 36 degrees here in Denison at high noon.

Meanwhile, restless crowds are said to be gathering outside of the PWC offices in scenic southwest Austin: "We want snow, we want snow, we want snow!"

[Ntxw]

Thanks for sharing that, I didn't realize MOS was effected as well. I use that product a lot for verification of raw output, and frankly often it is better as mentioned for reasons stated above. Definitely worth keeping in mind.

CFSv2 sees the cold now as well after this thaw, perfect weekend to come out of our hibernation briefly and enjoy the weather before it changes.

[PineyWoods]

I have a question now regarding making the meteograms. Are the excel speadsheets going to need to be edited to get the new GFS model to work with the current templates? I can't get the long range GFS model to work. It now goes from 240-384h instead of the old 192-384h. Not enough data points for copy and paste.
Thx

[orangeblood]

In addition to the teleconnection indices mentioned above turning much more favorable for another Arctic Outbreak, The Pacific Decadal Oscillation (PDO) just set a record positive index for the month of December...this normally translates into much below normal temps for February as well. The last month it was even close to that level was in December of 2002

Positive Phase

[wxman57]

I have a question now regarding making the meteograms. Are the excel speadsheets going to need to be edited to get the new GFS model to work with the current templates? I can't get the long range GFS model to work. It now goes from 240-384h instead of the old 192-384h. Not enough data points for copy and paste.
Thx

I just updated the spreadsheets to work with the upgraded GFS. Here's the link:

http://www.storm2k.org/phpbb2/viewtopic.php?f=22&t=109958

[orangeblood]

As Ntxw mentioned, get out and enjoy the warmup this weekend....GFS ENS releases the Arctic Hounds on the 12Z runs for the latter 10 days of the month....that is some really cold air for a mean this far out!!! What's scary is how cold Siberia looks, that air will be pouring over to North America continually reinforcing the cold North American trough...

[wxman57]

I don't see any really cold air over Texas through 384hrs on the new GFS. And look at those 500mb heights (in the 570+ decameter range)! Way high for this time of year (indicating no deep cold air). Cold for the Great Lakes & Northeast, though.



The 12Z GFS has below-normal temps across Texas, but mainly because it keeps the highs down in the 50s. Lows are in the 40s. Generally warmer than we've seen over the past week but still below normal:

[TeamPlayersBlue]

We need a nice Greenland block to really dump the cold air down. Pair that with a -EPO and Voila.

[orangeblood]

I don't see any really cold air over Texas through 384hrs on the new GFS. And look at those 500mb heights (in the 570+ decameter range)! Way high for this time of year (indicating no deep cold air). Cold for the Great Lakes & Northeast, though.

http://mag.ncep.noaa.gov/data/gfs/12/gf ... ort_ht.gif

The 12Z GFS has below-normal temps across Texas, but mainly because it keeps the highs down in the 50s. Lows are in the 40s. Generally warmer than we've seen over the past week but still below normal:

Grasping at straws are we ?? If that GFS ENS mean map I posted above doesn't worry you, I'm not sure what will....

[PineyWoods]

I have a question now regarding making the meteograms. Are the excel speadsheets going to need to be edited to get the new GFS model to work with the current templates? I can't get the long range GFS model to work. It now goes from 240-384h instead of the old 192-384h. Not enough data points for copy and paste.
Thx

I just updated the spreadsheets to work with the upgraded GFS. Here's the link:

http://www.storm2k.org/phpbb2/viewtopic.php?f=22&t=109958

Thank you

[wxman57]

I don't see any really cold air over Texas through 384hrs on the new GFS. And look at those 500mb heights (in the 570+ decameter range)! Way high for this time of year (indicating no deep cold air). Cold for the Great Lakes & Northeast, though.

http://mag.ncep.noaa.gov/data/gfs/12/gf ... ort_ht.gif

The 12Z GFS has below-normal temps across Texas, but mainly because it keeps the highs down in the 50s. Lows are in the 40s. Generally warmer than we've seen over the past week but still below normal:

Grasping at straws are we ?? If that GFS ENS mean map I posted above doesn't worry you, I'm not sure what will....

Not too worried about extreme cold. Again, note how high the 500mb heights are across Texas. 570+ decameters is quite high for winter. Oh, sure, highs may be a little below normal, but no significantly cold lows are indicated.

[orangeblood]

But we don't live at 500 MB though do we ? You and I both know the signatures for Arctic Outbreaks and the GFS ENS/Euro ENS means are both depicting those signatures at this time.

[Tireman4]

I don't see any really cold air over Texas through 384hrs on the new GFS. And look at those 500mb heights (in the 570+ decameter range)! Way high for this time of year (indicating no deep cold air). Cold for the Great Lakes & Northeast, though.

http://mag.ncep.noaa.gov/data/gfs/12/gf ... ort_ht.gif

The 12Z GFS has below-normal temps across Texas, but mainly because it keeps the highs down in the 50s. Lows are in the 40s. Generally warmer than we've seen over the past week but still below normal:

Grasping at straws are we ?? If that GFS ENS mean map I posted above doesn't worry you, I'm not sure what will....

Not too worried about extreme cold. Again, note how high the 500mb heights are across Texas. 570+ decameters is quite high for winter. Oh, sure, highs may be a little below normal, but no significantly cold lows are indicated.

But below normal temperatures (even low 30's which is not extreme cold) can produce interesting weather sir. Just sayin!!