Prognostic Meteorological Discussion
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000
FXUS02 KWBC 241531
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1030 AM EST FRI FEB 24 2017

VALID 12Z MON FEB 27 2017 - 12Z FRI MAR 03 2017

...OVERVIEW...

LARGE TROUGH IN THE WEST WILL CONTINUE TO PROGRESS EASTWARD TOWARD
THE CENTRAL PLAINS BY TUESDAY...GREAT LAKES BY WEDNESDAY...AND
WILL PUSH OFF THE EAST COAST BY THURSDAY/FRIDAY.  HIGH PRESSURE
WILL BUILD ACROSS THE WEST BY MIDWEEK AND WILL CONTINUE BUILDING
EAST ACROSS THE PLAINS THROUGH THE END OF THE WEEK.


...MODEL EVALUATION/PREFERENCES...

ENSEMBLES CONTINUED TO BE IN GOOD AGREEMENT OVER THE MEDIUM RANGE
PERIOD WITH SOME NOTABLE DIFFERENCES IN THE OPERATIONAL MODELS.
AT THE START OF THE MEDIUM RANGE PERIOD (MONDAY/TUESDAY)...THE
TROUGH ACROSS THE WEST WILL BEGIN TO LIFT NORTHEAST WHILE AN UPPER
RIDGE SETTLES ACROSS THE SOUTHEASTERN U.S.  BY MIDWEEK...THE
TROUGH WILL CENTER ACROSS THE CENTRAL PLAINS/UPPER MIDWEST WHILE
RIDGING CONTINUES TO BUILD ACROSS THE WEST.  BY THE END OF THE
WEEK...THE TROUGH WILL MOVE OVER THE EASTERN HALF OF CONUS WITH
RIDGING CONTINUING IN THE WEST.  THE 00Z GFS CONTINUED TO BE
FARTHER SOUTHEAST/FASTER THAN THE 00Z ECMWF WITH THE TROUGH
SWINGING ACROSS THE EAST AS THE MAIN COLD FRONT PUSHES OUT TOWARD
THE GREAT LAKES TO SOUTHERN PLAINS BY WEDNESDAY.  AS THE TROUGH
SHIFTS TOWARD THE EAST COAST BY THURSDAY/FRIDAY...THE GFS
CONTINUES TO BE ONE OF THE FASTER SOLUTIONS.  AN ECMWF/ECENS BASED
BLEND WITH CONTINUITY WAS USED WITH SOME GFS ADDED AS THERE WERE
ENSEMBLE SOLUTIONS SUGGESTING A FASTER TREND WITH THE TROUGH IN
THE EAST COULD BE POSSIBLE.


...WEATHER HIGHLIGHTS/THREATS...

WITH THE TROUGH LIFTING FROM THE CENTRAL PLAINS TOWARD THE
MISSISSIPPI VALLEY BY MIDWEEK...MODERATE TO LOCAL HEAVY RAINFALL
CAN BE EXPECTED ESPECIALLY ACROSS THE MID/LOWER MISSISSIPPI
VALLEY. THE POTENTIAL FOR SEVERE WEATHER FOR THIS REGION WILL BE
POSSIBLE ESPECIALLY ON WEDNESDAY (CHECK SPC PRODUCTS FOR MORE
INFORMATION).  AS THE SURFACE LOW LIFTS AND DEEPENS FROM THE
PLAINS TO THE GREAT LAKES...SNOW WILL LIKELY DEVELOP ON THE
NORTHWEST SIDE OF THE LOW AS IT APPROACHES THE UPPER MIDWEST/GREAT
LAKES.  ANOTHER SURGE OF WARMER AIR WILL BE IN PLACE ACROSS THE
EASTERN U.S. AHEAD OF THE COLD FRONT (+10-15F ABOVE AVERAGE).
HOWEVER...ONCE THE FRONT PASSES TEMPERATURES WILL RETURN BACK TO
NORMAL VALUES.  MOST OF THE WEST COAST...WITH THE EXCEPTION OF THE
PACIFIC NORTHWEST/NORTHERN ROCKIES...WILL REMAIN DRY DUE TO HIGH
PRESSURE STAYING IN PLACE.


REINHART/FRACASSO


$$





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