Cold for Thanksgiving

Some of the coldest air of the season will spill into the plains on Wednesday as a strong upper level storm establishes itself across the central US. 12Z NAM/WRF from this morning shows a cold air mass in place for Thanksgiving day.




The cold air will stay in place through the weekend while another storm may take shape in the southwest US. Depending on how this storm ejects to the east, there will be a chance for a round of wintry precip on the southern plains in the Fri/Sat/Sun (23-25) timeframe. Here's a graphic from Lubbock NWS.



ECMWF for Sat. morning shows the 500 hPa vort max situated over Arizona, a much slower solution than the GFS. Track of this low will be important for any snowfall throughout the region.

ECMWF:

GFS:

Locations in the eastern OK panhandle will likely see cold temps throughout the week with highs struggling to hit 40F. The coldest mornings seem to be Thursday and Friday mornings as widespread upper teens could be a reality. Very slight chance of a snow flurry or two Wednesday morning but a higher chance of some wintry precip may come later in the week (23-25) with the associated storm system mentioned above. Still a lot of details to pinpoint before a quality forecast could be made though.

Cold on the Way

A quick post to notify those interested in the storm system that will dig into the intermountain west during the week of Thanksgiving. Snow is quite possible on the front range and into western Kansas and maybe even TX/OK panhandle. Right now I won't go into much detail as the models are still in disagreement. I'll post a lengthy post about what I see over the weekend when hopefully my early forecast will be fine tuned. In the mean time, I think DDC forecast office sums up the situation pretty well as of now:

WEST TO NORTHWESTERLY FLOW ALOFT WILL BE SITUATED OVER THE
CENTRAL PLAINS AGAIN TO BEGIN THE PERIOD. NUMERICAL MODELS ARE IN
SOME AGREEMENT INDICATING THIS PATTERN CONTINUING THROUGH MONDAY
UNTIL AN UPPER LEVEL TROUGH OF LOW PRESSURE BEGINS TO COME ASHORE IN
THE PACIFIC NORTHWEST. HOWEVER, THE GFS AND CANADIAN ARE A JUST A
BIT MORE AMPLIFIED WITH THE TROUGH THAN THE ECMWF DIGGING SOUTHWARD
AS IT MOVES INTO THE ROCKY MOUNTAIN REGION BY EARLY TUESDAY. THE
MODELS REALLY BEGIN TO DIVERGE BY WEDNESDAY. THE ECMWF BEGINS TO
SHOW THE UPPER LEVEL TROUGH DIGGING DEEP OVER THE DESERT SOUTHWEST
WITH A MORE POSITIVE TILT AND CLOSING OFF OF THE LOW. THE GFS CLOSES
OFF THE LOW AS WELL BUT INDICATES THE UPPER LEVEL TROUGH BECOMING
LESS AMPLIFIED THAN THE ECMWF AND LESS POSITIVELY TILTED. THE MODELS
REALLY BEGIN TO SPLIT APART BY DAY SEVEN WITH THE GFS SHOWING THE
UPPER LEVEL LOW EJECTING NORTHEAST INTO THE GREAT LAKES REGION WHILE
THE ECMWF KEEPS THE UPPER LOW CLOSED OFF AND OVER THE DESERT
SOUTHWEST. THE 12Z GFS ENSEMBLE MEMBERS LEANED MORE TOWARDS THE
OPERATIONAL GFS BUT A LITTLE SLOWER. REGARDLESS, EXPECT MUCH COLDER
AIR TO BEGIN ADVECTING INTO WESTERN KANSAS BY TUESDAY IN WAKE OF A
PASSING COLD FRONT. ALSO EXPECT THE POSSIBILITY OF PRECIPITATION TO
PICK UP IN THE TUESDAY/WEDNESDAY TIME FRAME IN ASSOCIATION WITH THIS
UPPER LEVEL SYSTEM. HOWEVER, UNCERTAINTY PREVAILS THIS FAR OUT WITH
TIMING BEING AN ISSUE ALONG WITH PRECIPITATION TYPE. THE LATEST 12Z
GFS RUN AND 12Z GFS MODEL SOUNDING INDICATES COLDER LOW AND MID
LEVELS WITH TEMPERATURES WELL BELOW 0(C) BY 00Z THURSDAY. THE 12Z
ECMWF IS SOMEWHAT WARMER THAN THE GFS. THE GFS TRACKS THE LOW OVER
THE CWA WHILE THE ECMWF LAGS 24-48 HOURS BEHIND AND TRACKS THE LOW A
LITTLE FURTHER NORTH. WILL KEEP GOING POPS AND WEATHER TYPE DUE TO
THIS MUCH UNCERTAINTY THIS FAR OUT.

http://www.crh.noaa.gov/product.php?site=NWS&issuedby=DDC&product=AFD&format=CI&version=1&glossary=1

Boring Warm November so far

Not much to talk about with the quite weather pattern we've been in. Some medium-long range models are hinting at a more active pattern including some potentially cold air for the central and southern plains along with much of the east. Other than that, I've had plenty of time to think of new ideas for my website, www.capturethestorm.com , including a video section and some timelapse video segments. I'll have plenty of time in December to work on those types of things.

Sam