Prognostic Meteorological Discussion
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FXUS02 KWBC 090613
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
113 AM EST TUE FEB 09 2016

VALID 12Z FRI FEB 12 2016 - 12Z TUE FEB 16 2016

...RECORD COLD FOR PORTIONS OF THE NORTHEAST THIS WEEKEND...


...OVERVIEW...

THE ARCTIC WILL UNLOAD ITS COLD AIR DIRECTLY INTO THE NORTHEASTERN
CONUS THIS WEEKEND BEFORE SETTLING INTO A MORE TYPICAL
RIDGE/TROUGH PATTERN FROM WEST TO EAST EARLY NEXT WEEK. RECORD
COLD TEMPERATURES ARE LOOKING MORE AND MORE LIKELY FOR PORTIONS OF
THE GREAT LAKES/MIDWEST/CENTRAL AND SOUTHERN
APPALACHIANS/MID-ATLANTIC/NORTHEAST AND PERHAPS INTO FLORIDA AS
WELL.


...GUIDANCE EVALUATION/PREFERENCES...

BIGGEST SHIFT IN THE GUIDANCE OVER THE PAST 24-36 HRS HAS BEEN IN
THE PAC NW WHERE THE GEFS WERE FIRST TO CLUE INTO A DIFFERENT
HANDLING OF A N-S ELONGATING TROUGH ALONG 135W AROUND FRIDAY. THE
ECMWF/CANADIAN ENSEMBLES SHIFTED TOWARD THE GEFS SOLUTION BUT MORE
OR LESS MET IN THE MIDDLE. THIS SHOULD RESULT IN A DETACHED CLOSED
LOW WELL SOUTHWEST OF CALIFORNIA THIS WEEKEND INTO EARLY NEXT WEEK
RATHER THAN OVER THE SW STATES PER SOME EARLIER DETERMINISTIC
RUNS. AS THE DEEP TROUGH IN THE EAST LIFTS OUT, THIS WILL LEAVE
ROOM FOR THE WESTERN SHORTWAVE TO FILL IN BEHIND IT AND SLIDE
SOUTHEASTWARD NEXT MON/TUE. THE MODELS/ENSEMBLES ARE IN RELATIVELY
GOOD AGREEMENT ON THE SYNOPTIC PATTERN BUT THE GFS REMAINS SLOWER
THAN THE ECMWF/CANADIAN AND NEARLY ALL ENSEMBLE MEMBERS IN THE PAC
NW SAT/SUN. 12Z/08 CANADIAN WAS CLOSER TO THE ECMWF/ENSEMBLES SO
THAT CLUSTER WAS USED FOR THE SECOND HALF OF THE FORECAST --
SUN-TUE WHILE A CONSENSUS INCLUDING SOME OF THE GFS WAS USED FOR
THE FRI/SAT FORECAST.

BY NEXT MON/TUE... MODELS HAVE SHOWN SOME INTERESTING SOLUTIONS IN
THE EAST... WITH THE POTENTIAL FOR THE SHORTWAVE TO MANIFEST
ITSELF MORE FORCEFULLY AT THE SURFACE. FOR NOW, WILL STICK WITH A
BROAD ENSEMBLE COMPROMISE AND DEPICTED A PAIR OF SFC LOWS IN THE
SOUTHEAST WITH ROOM TO ADJUST. DEPTH/STRENGTH OF COLD AIR EXITING
THE EAST WILL PLAY A ROLE IN HOW THINGS PLAY OUT, INCLUDING ANY
NORTHERN STREAM ENERGY MOVING THROUGH THE UPPER MIDWEST AND GREAT
LAKES -- ANOTHER UNKNOWN.


...SENSIBLE WEATHER HIGHLIGHTS...

WEST: AREAS GENERALLY WEST OF 100W SHOULD SEE NEAR TO ABOVE NORMAL
TEMPERATURES WITH SOME LOCATIONS APPROACHING/EXCEEDING RECORD HIGH
MAXES AND HIGH MINS. PRECIPITATION SHOULD FOCUS MOST ON WASHINGTON
AND INTO NORTHERN IDAHO AND WESTERN MONTANA AS THE SHORTWAVE
PUSHES THROUGH.

EAST: WELL BELOW AVERAGE TEMPERATURES CENTERED IN THE CENTRAL
APPALACHIANS INTO THE MID-ATLANTIC. DAYTIME TEMPERATURES WILL BE
QUITE COLD AND COULD BREAK RECORD LOW MAXES BY SEVERAL DEGREES IN
SOME LOCATIONS, DEPENDING ON TEMPERATURES JUST PAST MIDNIGHT ON
SATURDAY. COLD AIR WILL HELP MAINTAIN THE LAKE EFFECT MACHINE AND
WILL ALSO FAVOR THE UPSLOPE AREAS IN THE APPALACHIANS UNTIL THE
SURFACE HIGH MOVES THROUGH. BY NEXT WEEK, FOCUS WILL TURN TO THE
SOUTHEASTERN STATES WHERE PRECIPITATION SHOULD EXPAND
NORTHEASTWARD. COLD AIR IS USUALLY LOATHE TO RETREAT AS FAST AS
THE MODELS INDICATE -- ESPECIALLY RECORD COLD -- SO ICING MAY BE
AN ADDITIONAL THREAT DEPENDING ON HOW THINGS DEVELOP.


FRACASSO

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