Prognostic Meteorological Discussion
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FXUS02 KWBC 260343
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1043 PM EST SAT FEB 25 2017

VALID 12Z WED MAR 01 2017 - 12Z SUN MAR 05 2017

...OVERVIEW AND GUIDANCE PREFERENCES...

ONE FRONTAL BOUNDARY IS FORECAST TO PROGRESS THROUGH THE EASTERN
THIRD OF THE LOWER 48 WED-THU BEFORE ANOTHER SYSTEM ENTERS THE
PACIFIC NORTHWEST ON FRIDAY AND MOVES ACROSS THE NORTHERN TIER
NEXT WEEKEND. THE MODELS AND ENSEMBLES REMAIN IN GENERALLY GOOD
AGREEMENT AND A CONSENSUS APPROACH WAS USED AS A STARTING POINT.
THE RECENT 12Z/18Z GFS RUNS LAGGED BEHIND THE ECMWF AND THE 12Z
NAEFS MEAN WITH THE EVOLVING SFC LOW INTO THE NORTHEAST LATE
WEDNESDAY WHILE THE ECMWF ENSEMBLE MEAN WAS QUICKEST. AN AVERAGE
SOLUTION WAS PREFERRED GIVEN SOME JUMPINESS IN TIMING/TRACK OVER
THE PAST COUPLE OF DAYS. TO THE WEST, THE 12Z/18Z GFS AGAIN LAGGED
BEHIND THE LARGER ENSEMBLE CLUSTER (ECMWF WITH ITS MEAN AND THE
GEFS/CANADIAN MEANS) BUT WAS NOT TOTALLY UNACCEPTABLE. UPPER
PATTERN HAS YET TO BE RESOLVED OVER THE NORTHEASTERN PACIFIC INTO
NEXT WEEKEND AS TELECONNECTIONS FAVOR TROUGHING OVER THE WEST BUT
THE GEFS MEAN WAS FLAT AND THE ECMWF ENSEMBLE MEAN SHOWED RIDGING.


...WEATHER HIGHLIGHTS/THREATS...

SHOWERS WITH EMBEDDED HEAVY RAIN AND CONVECTION SHOULD FOCUS ALONG
AND AHEAD OF THE COLD FRONT PUSHING THROUGH THE EAST INTO
THURSDAY. PLEASE CONSULT THE STORM PREDICTION CENTER FOR MORE
INFORMATION ON THE RISK OF SEVERE WEATHER. SNOW AND STRONG WINDS
WILL BE POSSIBLE TO THE NORTHWEST OF THE SURFACE LOW IN THE GREAT
LAKES. BEHIND THIS SYSTEM, PRECIPITATION COVERAGE SHOULD DECREASE
ACROSS THE CONUS LATER IN THE WEEK, WITH THE EXCEPTION OF THE
NORTHWEST, WHERE MODERATE TO HEAVY RAIN AND HIGHER ELEVATION SNOW
WILL BE POSSIBLE WITH STRONG ONSHORE FLOW.

AFTER A SHORT-LIVED WARM DAY IN THE EAST ON WEDNESDAY (RECORD HIGH
TEMPERATURES POSSIBLE) TEMPERATURES SHOULD FALL BACK TOWARD MORE
TYPICAL LEVELS IN THE EAST AFTER THE FRONT CLEARS THE COAST.
TEMPERATURES SHOULD RISE BACK ABOVE AVERAGE IN THE WEST AND THEN
THE PLAINS BY NEXT FRIDAY INTO THE WEEKEND, PERHAPS PUSHING BACK
TO THE EAST COAST BY NEXT SUNDAY AS THE SURFACE HIGH MOVES
OFFSHORE.


FRACASSO


$$





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