Southern Plains winter wx thread (2008-2009)

[Stephanie]

I'm surprised at the lack of snowpack in the Rockies - that really caught my eye. The second thing to catch my eye was the patch of white in Southern New Jersey, of all places (where I live)!

[Extremeweatherguy]

Latest from the Norman, OK NWS office...

THERE STILL ARE INDICATIONS OF AN ARCTIC INTRUSION WITH MORE BITE
TO IT ARRIVING NOT LONG AFTER THE CURRENT 7-DAY FORECAST...
POSSIBLY INTO OK AS EARLY AS MONDAY 3 DECEMBER PER LATEST
GFS/ECMWF. 00Z GFS HAS RELENTED FROM THE 1062MB CANADIAN SFC HIGH
ON LAST NIGHT`S 06Z RUN... BUT STILL DEPICTS A DECIDEDLY COLD
LONGWAVE PATTERN FOR MUCH OF THE NATION BY DAY 10. STRONG UPPER
RIDGE NEAR W COAST AND STRONGLY MERIDIONAL N FLOW DOWNSTREAM WITH
BL TEMPS IN THE 30S F AND 850MB TEMPS APPROACHING -10C OVER OK.
ECMWF LIKEWISE LOOKS COLD... EVEN WORKING THE ARCTIC AIR
INTO/ACROSS THE ROCKIES INTO THE INTERMOUNTAIN WEST. THIS DOES
NOT CURRENTLY LOOK LIKE A RIVAL TO SOME OF THE MORE INFAMOUS
RECORD COLD OUTBREAKS OF DECEMBER 1983 AND 1989... BUT IF IT PANS
OUT IT WILL LIKELY BE THE COLDEST SO FAR THIS SEASON WITH AN
ATTENDANT INCREASING POTENTIAL FOR WINTER-TYPE PRECIP THE WEEK
AFTER NEXT.

[Kennethb]

Most of the ensembles take the AO negatively off the charts:

http://www.cpc.ncep.noaa.gov/products/p ... ensm.shtml

[Extremeweatherguy]

Most of the ensembles take the AO negatively off the charts:

http://www.cpc.ncep.noaa.gov/products/p ... ensm.shtml

Very interesting. That is usually a good sign that an arctic plunge is on its way.

[Ed Mahmoud]

Most of the ensembles take the AO negatively off the charts:

http://www.cpc.ncep.noaa.gov/products/p ... ensm.shtml

Very interesting. That is usually a good sign that an arctic plunge is on its way.

Interesting duel of the models in about a week...

[Extremeweatherguy]

I hope he doesn't mind me quoting him here, but this is what our old buddy wxman57 had to say about the upcoming cold on another weather board...

GFS and ECMWF have backed off on the predicted cold outbreak early next week. There is a pattern change in the works, though. I'd look for the cold air to reach us the 2nd-3rd week of December, not the first week.

[iorange55]

I hope he doesn't mind me quoting him here, but this is what our old buddy wxman57 had to say about the upcoming cold on another weather board...

GFS and ECMWF have backed off on the predicted cold outbreak early next week. There is a pattern change in the works, though. I'd look for the cold air to reach us the 2nd-3rd week of December, not the first week.

If that's true, that would line up with the old farmers almanac forecast. Calling for snow and ice and record cold. But I'm not sure how accurate they are.

[Extremeweatherguy]

From the Norman, OK morning AFD...

THEREFORE...THE EXTENDED FORECAST IS BASED HEAVILY ON THE
ECMWF...AND FEATURES RELATIVELY COOL AND DRY NORTHWEST FLOW FOR OUR
REGION. WE DID INCLUDE LOW POPS FOR A JET STREAK ON SUNDAY.
POTENTIALLY THE MOST NOTEWORTHY EVENT...THOUGH...IS AN ALASKAN
ARCTIC FRONT THAT THE ECMWF BRINGS DOWN NEXT TUESDAY NIGHT. ALTHOUGH
WE DO NOT HAVE CONFIDENCE IN THE EXACT TIMING OR MAGNITUDE OF THE
COLD AIR...THE EVENT IS PLAUSIBLE GIVEN THE UPPER AIR PATTERN AND
TIME OF YEAR. DESPITE DIFFERING IN THE DETAILS...THE MODELS HAVE
HINTED AT THIS FOR SEVERAL CONSECUTIVE RUNS.

[Extremeweatherguy]

The Norman, OK NWS office is still excited about arctic air for next week...

BY FRIDAY...RAIN SHOULD TAPER OFF IN THE SOUTHEAST...AND COLD HIGH
PRESSURE WILL SETTLE INTO THE REGION...KEEPING HIGHS IN THE 40S AND
50S. NORTHWEST FLOW SETS UP...BUT THE MODELS CONTINUE TO DIFFER IN
HANDLING WAVES WITHIN THE FLOW...AND HOW MUCH COLD AIR WILL SLIDE
DOWN THROUGH THE PLAINS. THE PATTERN IN THE OPERATIONAL GFS LOOKS
REASONABLE...BUT THAT MODEL HAS TENDED TO MOVES SHORT WAVES TOO
QUICKLY...AND IS TAPPING UNUSUALLY COLD AIR...CONSIDERING THAT THE
SOURCE REGION IS NORTH OF THE GREAT LAKES...AND THAT AIR USUALLY
SLIDES TO OUR EAST. WE ADJUSTED THE MOS TOWARD NUMBERS FROM THE GFS
ENSEMBLE MEAN...WHICH IS NOT QUITE AS COLD. THE PERIOD OF REAL
INTEREST...THOUGH OUT AT DAY 8...NEXT TUESDAY NIGHT/WEDNESDAY. THE
ENSEMBLE AND THE ECMWF HAVE CONSISTENTLY INDICATED THAT A SHOT OF
ARCTIC AIR WILL COME AT US FROM A MORE FAVORABLE TRAJECTORY OUT OF
WESTERN CANADA. STAY TUNED.

[cheezyWXguy]

The Norman, OK NWS office is still excited about arctic air for next week...

BY FRIDAY...RAIN SHOULD TAPER OFF IN THE SOUTHEAST...AND COLD HIGH
PRESSURE WILL SETTLE INTO THE REGION...KEEPING HIGHS IN THE 40S AND
50S. NORTHWEST FLOW SETS UP...BUT THE MODELS CONTINUE TO DIFFER IN
HANDLING WAVES WITHIN THE FLOW...AND HOW MUCH COLD AIR WILL SLIDE
DOWN THROUGH THE PLAINS. THE PATTERN IN THE OPERATIONAL GFS LOOKS
REASONABLE...BUT THAT MODEL HAS TENDED TO MOVES SHORT WAVES TOO
QUICKLY...AND IS TAPPING UNUSUALLY COLD AIR...CONSIDERING THAT THE
SOURCE REGION IS NORTH OF THE GREAT LAKES...AND THAT AIR USUALLY
SLIDES TO OUR EAST. WE ADJUSTED THE MOS TOWARD NUMBERS FROM THE GFS
ENSEMBLE MEAN...WHICH IS NOT QUITE AS COLD. THE PERIOD OF REAL
INTEREST...THOUGH OUT AT DAY 8...NEXT TUESDAY NIGHT/WEDNESDAY. THE
ENSEMBLE AND THE ECMWF HAVE CONSISTENTLY INDICATED THAT A SHOT OF
ARCTIC AIR WILL COME AT US FROM A MORE FAVORABLE TRAJECTORY OUT OF
WESTERN CANADA. STAY TUNED.

sounds like theyre the only ones...I havent heard anything about this from any other office, let alone any model anymore. The only thing close I can find is that weather.com predicts rain with a low of 36 for next week sometime, but we all know how reliable weather.com is...

[iorange55]

The Norman, OK NWS office is still excited about arctic air for next week...

BY FRIDAY...RAIN SHOULD TAPER OFF IN THE SOUTHEAST...AND COLD HIGH
PRESSURE WILL SETTLE INTO THE REGION...KEEPING HIGHS IN THE 40S AND
50S. NORTHWEST FLOW SETS UP...BUT THE MODELS CONTINUE TO DIFFER IN
HANDLING WAVES WITHIN THE FLOW...AND HOW MUCH COLD AIR WILL SLIDE
DOWN THROUGH THE PLAINS. THE PATTERN IN THE OPERATIONAL GFS LOOKS
REASONABLE...BUT THAT MODEL HAS TENDED TO MOVES SHORT WAVES TOO
QUICKLY...AND IS TAPPING UNUSUALLY COLD AIR...CONSIDERING THAT THE
SOURCE REGION IS NORTH OF THE GREAT LAKES...AND THAT AIR USUALLY
SLIDES TO OUR EAST. WE ADJUSTED THE MOS TOWARD NUMBERS FROM THE GFS
ENSEMBLE MEAN...WHICH IS NOT QUITE AS COLD. THE PERIOD OF REAL
INTEREST...THOUGH OUT AT DAY 8...NEXT TUESDAY NIGHT/WEDNESDAY. THE
ENSEMBLE AND THE ECMWF HAVE CONSISTENTLY INDICATED THAT A SHOT OF
ARCTIC AIR WILL COME AT US FROM A MORE FAVORABLE TRAJECTORY OUT OF
WESTERN CANADA. STAY TUNED.

sounds like theyre the only ones...I havent heard anything about this from any other office, let alone any model anymore. The only thing close I can find is that weather.com predicts rain with a low of 36 for next week sometime, but we all know how reliable weather.com is...

I know, no one else seems to be talking about it. Although i haven't really looked at any ecmwf models so I don't know.

[Extremeweatherguy]

The ECMWF is definitely showing a much chillier pattern than the GFS in the long range, and since it is usually better than the GFS in the 168 hour+ timeframe, it is certainly exciting.

In the shorter term - It is looking pretty chilly when I return to OKC on Sunday. The latest NWS forecast is calling for a high of 47F Sunday afternoon and a low of 27-28F Sunday night under "Mostly cloudy skies with isolated sprinkles". Given the expected depth of the cold air, it would not surprise me one bit if the wording "sprinkles" eventually turned into "flurries" in future NWS forecasts. I am crossing my fingers!

[Extremeweatherguy]

Brrr! The 18z GFS is showing a decent snowstorm (and very cold air) impacting the southern plains on December 4th and 5th...







...If this plays out, then it may be Oklahoma City's first accumulating snowfall of the winter.

[iorange55]

Brrr! The 18z GFS is showing a decent snowstorm (and very cold air) impacting the southern plains on December 4th and 5th...







...If this plays out, then it may be Oklahoma City's first accumulating snowfall of the winter.

If that plays out I'm making the 2 or 3 hour drive up north.

[Extremeweatherguy]

The 00z GFS is not as aggressive with a winter storm next week, but it does have an overall stormier look to it than some of the previous GFS runs.

[iorange55]

I just wonder why the GFS doesn't really show the cold cold cold air next week. I thought the GFS was more aggressive with cold outbreaks and storms?

[iorange55]

New Noaa discussions not looking all that great, even the cold air next week doesn't seem as cold. This is depressing, it's still early though not even December I guess it's just more depressing since everyone is saying December will be the coldest month.



Happy thanksgiving everyone.

[Extremeweatherguy]

From the Norman, OK NWS morning forecast discussion...

ANOTHER STRONG JET STREAK ENTERS THE BASE OF OUR LOCAL TROUGH
SUNDAY...AND WE MAINTAINED A FORECAST OF SPRINKLES/VIRGA. IT IS
LIKELY TO BE A RAW DAY WITH BRISK WINDS. FROM MON-WED...WE FOLLOWED
THE ENSEMBLE MEAN...WHICH SEEMS TO BETTER HANDLE THE NEXT MEDIUM
WAVELENGTH TROUGH COMING OUT OF THE PACIFIC. THIS ONE IS IN PRIME
POSITION TO TAP COLD AIR OUT OF NORTHWEST CANADA...WHICH SLIDES DOWN
THE HIGH PLAINS AS A 1036 HIGH NEXT TUESDAY NIGHT/WEDNESDAY. THIS
SHOULD BE THE COLDEST AIR YET THIS SEASON...BUT IT MAY NOT BE TOO
DRAMATIC...GIVEN HOW QUICKLY IT DEVELOPS AND DISLODGES...RATHER THAN
BUILDING UP OVER A LONGER PERIOD OF TIME.

[jinftl]

First CPC Outlook that shows deep trough and below normal temps in east starting to lift out in the extended outlook...

[Extremeweatherguy]

00z ECMWF = Brrr.

http://www.ecmwf.int/products/forecasts ... 00!!!step/