Prognostic Meteorological Discussion
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000
FXUS02 KWBC 290711
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
310 AM EDT MON MAY 29 2017

VALID 12Z THU JUN 01 2017 - 12Z MON JUN 05 2017


PATTERN OVERVIEW AND MODEL PREFERENCES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
TROUGHING IS EXPECTED ACROSS THE NORTHWEST AND NORTHEAST WITH
SYSTEMS MOVING THROUGH THE SOUTHWEST INTO THE SOUTHERN PLAINS.
THE MID-LEVEL VORTEX ACROSS THE GREAT LAKES IS EXPECTED TO
RELOAD/STRENGTHEN NEXT MONDAY, WHICH SHOULD KEEP SUMMER-LIKE
READINGS AT BAY FOR THE TIME BEING.  FOR THE PRESSURES, 500 HPA
HEIGHTS, AND WIND GRIDS USED A BLEND THAT WAS MORE DETERMINISTIC
HEAVY EARLY ON (12Z ECMWF, 12Z CANADIAN, 12Z UKMET, AND 18Z GFS)
WITH INCREASINGLY AMOUNTS OF ENSEMBLE MEAN GUIDANCE LATE.  FOR THE
TEMPERATURES, RAIN CHANCES, CLOUDS, DEW POINTS, AND WEATHER GRIDS,
USED AN EVEN SPLIT OF THE 12Z ECMWF/18Z GFS/12Z CANADIAN AND THE
12Z NAEFS/12Z ECMWF ENSEMBLE MEANS.  THE DAYS 4-7 QPF IS A ROUGH
COMPROMISE OF THE 12Z ECMWF/00Z GFS THAT WAS ADJUSTED SOMEWHAT
SOUTHWARD.


WEATHER HIGHLIGHTS
~~~~~~~~~~~~~~~~~~
NEAR TO BELOW AVERAGE TEMPERATURES ARE EXPECTED TO CONTINUE INTO
EARLY NEXT WEEK ACROSS THE GREAT LAKES AND NORTHEAST DUE TO
LINGERING UPPER LEVEL TROUGHING, WITH SHOWERS AND POSSIBLY
THUNDERSTORMS OCCURRING IN THE REGION DUE TO COLD AIR ALOFT.
MEANWHILE, WARM CONDITIONS ARE EXPECTED ACROSS MUCH OF
INTERMOUNTAIN WEST...WITH AN APPROACHING COLD FRONT BRINGING SOME
ASSOCIATED LATE-SEASON PRECIPITATION TO THE NORTHWEST/NORTHERN
ROCKIES.

THE MOST WIDESPREAD/HEAVIEST RAINS THIS PERIOD ARE FORECAST ACROSS
THE SOUTHERN PLAINS AND MIDWEST INTO THE OHIO VALLEY AND CENTRAL
APPALACHIANS WITH THE WAVE(S) MOVING EAST FROM THE SOUTHWEST US --
LOCALLY HEAVY RAINS ARE ANTICIPATED IN AREAS THAT HAVE RECEIVED
ABOVE NORMAL RAINFALL DURING THE PAST MONTH OR TWO.  BEHIND A
TRAILING COLD FRONT, TEMPERATURES SHOULD SHIFT BELOW NORMAL ACROSS
MUCH OF THE DEEP SOUTH/GULF COAST EARLY NEXT WEEK.

ROTH/PETERSEN
$$




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