Prognostic Meteorological Discussion
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000
FXUS02 KWBC 231600
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1159 AM EDT THU MAR 23 2017

VALID 12Z SUN MAR 26 2017 - 12Z THU MAR 30 2017

...OVERVIEW/GUIDANCE EVALUATION/PREFERENCES...

A RATHER ACTIVE MEDIUM RANGE PERIOD PERIOD COMING UP FOR THE
LATTER PART OF THE WEEKEND INTO NEXT MID WEEK... AS PATTERN
ADJUSTS TO SPRING. A SERIES OF SPLIT FLOW PAC STORM SYSTEMS WILL
MOVE INTO THE WEST COAST BEFORE THE SOUTHERN STREAM INTENSIFIES
AND TAKES CONTROL. THUS A PARADE OF ACTIVE SYSTEMS WILL MOVE FROM
THE DESERT SW... EJECT INTO THE PLAINS/MS VALLEY AND EVENTUALLY
REACH THE EAST. THIS COULD SPELL SEVERAL DAYS FOR SEVERE WEATHER
AND POSSIBLE EXCESSIVE RAINS.

THE FIRST SUCH ACTIVE UPPER JET AND SHORT WAVE TROUGH IS ALREADY
ADVANCING THROUGH THE FOUR CORNERS REGION TODAY. THIS SYSTEM IS
PROGGED BY THE GUIDANCE TO BE LOCATED OVER THE MID MS/WESTERN OH
VALLEYS. THE MODELS HANDLE THIS FEATURE REASONABLY WELL... AS IT
SLOWLY PRESSES DOWNSTREAM... WEAKENS AND RUNS INTO A RATHER
FORMIDABLE UPPER RIDGE. THE ADVANCEMENT OF THIS FEATURE INITIALLY
IS FROM A KICKER SYSTEM UPSTREAM WHICH ON SUN WILL BE OVER THE
FOUR CORNERS REGION AND EJECTING OUT INTO THE CENTRAL/SRN PLAINS.
THIS SYSTEM WILL TAKE A SIMILAR STORM PATH FROM THE PLAINS INTO
THE MID MS VALLEY AND OH VALLEY BEFORE MESHING OR PARTIALLY
INTERACTING WITH AN ACTIVE NORTHERN STREAM SYSTEM ON TUES. THE
RESULTING SYSTEM WILL THEN MOVE THROUGH THE EAST TUES/WED. ALSO
LATE SUN INTO MON... THE NEXT PAC/MARITIME UPPER TROUGH WILL MOVE
INTO THE WEST COAST. ONCE AGAIN... DIGGING SRN BRANCH WILL DRIVE A
POTENT SYSTEM THROUGH THE DESERT SW AND FOUR CORNERS REGION INTO
THE CENTRAL/SRN PLAINS... THOUGH A FAIR AMOUNT OF SPREAD SURROUNDS
THE PROGRESSION OF THIS FEATURE.

OVERALL WPC PREFERRED TO FOLLOW A MAJORITY BLEND OF THE
OPERATIONAL 00Z/06Z GFS AND 00Z ECMWF/UKMET WITH SMALL PERCENTAGES
OF THE GEFS/EC/NAEFS MEAN THROUGH TUES... THOUGH MEANS INCREASING
EACH DAY. THEN GIVEN THE LARGE PROGRESSION SPREAD... EC FAST AND
GFS SLOW... ON THE SYSTEM KICKING OUT INTO THE PLAINS/MS VALLEY ON
WED AND THURS... WHILE NEXT PAC SYSTEM MOVES INTO WEST COAST AND
DIGS INTO THE DESERT SW. WPC HERE PREFERRED A MAJORITY BLEND OF
THE GEFS/EC/NAEFS MEANS WITH VERY SMALL PERCENTAGES OF THE
OPERATIONAL GFS/ECMWF.

...SENSIBLE WEATHER/HIGHLIGHTS...

CONCERNING THE SYSTEM STARTING OVER THE MID MS VALLEY AND OH/TN
VALLEYS... EXPECT SCATTERED SHOWERS/STORMS FROM THE OH/TN VALLEYS
AND APPALACHIANS INTO THE MID-ATL AND NORTHEAST ON SUN AND MON...
WITH A LOCALIZED MAX FOR QPF OF WARM SECTOR AND OVERRUNNING INTO
COLD SECTOR FROM THE EASTERN OH VALLEY INTO PA TO THE
NORTHEAST/SRN NEW ENGLAND COAST COAST... WHILE VERY NRN EDGE OF
THIS SYSTEM COULD DELIVER MORE WINTER WEATHER FOR NRN NEW ENGLAND
AND MAINE.

FOR THE STORM SYSTEM EMERGING FROM THE CENTRAL/SRN ROCKIES INTO
THE PLAINS ON SUN AND PROCEEDING THROUGH THE MIDWEST AND EAST SUN
THROUGH WED. EXPECT SCATTERED SHOWERS/STORMS FROM IA/KS/MO SOUTH
AND WEST INTO TX WITH SOME SEVERE AND LOCALLY HEAVY RAINS ON SUN.
PRECIPITATION CHANCES INCREASING ON MON WITH SHOWERS/STORMS
EXTENDING FROM WESTERN GREAT LAKES/OH VALLEY AND MID MS VALLEY TO
THE SOUTH/CENTRAL GULF COAST REGION... SEVERE THREAT FROM SR/LA
EAST TO SRN APPALACHIANS WITH LOCALLY HEAVY RAIN AND A
LOCAL/ISOLATED THREAT FROM MO/IA INTO IL AND OH VALLEY FOR
SEVERE/HEAVY RAIN. THEN TUES AND WED... A POSSIBLE THREAT
ORGANIZED PRECIP FROM THE MID-ATL REGION TO THE NERN QUAD OF THE
COUNTRY BUT THIS REMAINS HIGHLY UNCERTAIN.

THE SYSTEM ARRIVING INTO THE WEST COAST LATE SUN INTO MON...
EXPECT LOCALLY HEAVY RAINS FROM THE PAC NW TO NRN CA AND PERHAPS
CENTRAL CA WITH MTN SNOW. WIDESPREAD PRECIP ON MON ACROSS MUCH OF
THE WEST... ESPECIALLY INVOF NV/UT INTO AZ... AND MOISTURE
CONTINUING ACROSS THE FOUR CORNERS REGION ON TUES WITH POSSIBLE
DRY LINE CONVECTION/HEAVY RAINS ERN CO/NM INTO OK/TX PANHANDLES.
THEN ON WED AND THURS... POSSIBLE WIDESPREAD CONVECTION AND HEAVY
RAINS FROM THE CENTRAL/SRN PLAINS AND ADVANCING DOWNSTREAM BUT DUE
TO SPREAD TO DETERMINE HOW FAR DOWNSTREAM... WHILE MOISTURE
RETURNS UPSTREAM ACROSS THE PAC NW INTO THE INTER-MOUNTAIN WEST
THESE DAYS.

OVERALL 5 DAY MEAN MAX TEMP ANOMALIES SUGGEST NEAR AVG TO SLIGHTLY
BELOW AVG ACROSS THE PAC NW/INTERIOR NW INTO CA AND FOR THE
NORTHEAST DUE TO THE BACK DOOR COLD FRONT. FOR THE REST OF THE
COUNTRY FROM THE FRONT RANGE OF THE ROCKIES TO THE EASTERN
SEABOARD MINUS NEW ENGLAND COULD BE AS MUCH AS 5 TO 15 DEG ABOVE
AVG.


MUSHER

$$




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