Prognostic Meteorological Discussion
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000
FXUS02 KWBC 281601
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1200 PM EDT FRI AUG 28 2015

VALID 12Z MON AUG 31 2015 - 12Z FRI SEP 04 2015

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

MODELS CONTINUE TO DEPICT A LARGE-SCALE UPPER-LEVEL TROUGH
GRADUALLY ACQUIRING MORE AMPLITUDE WITH TIME NEAR THE WEST COAST
OF NORTH AMERICA.  THE EC ENSEMBLE MEAN CONTINUES TO SHOW A
FLATTER TROUGH WHEREAS THE GEFS CONTINUE TO FORECAST A HIGHER
AMPLITUDE TROUGH.  HOWEVER...THE LATEST 00Z EC ENSEMBLE HAS
TRENDED TOWARD A HIGHER AMPLITUDE SOLUTION FROM YESTERDAY`S 12Z
RUN BUT IS STILL LESS AMPLIFIED THAN THE 00Z AND THE 06Z GEFS
MEANS.  GIVEN THE ACTIVE TROPICAL CYCLONE ACTIVITIES CURRENTLY IN
THE CENTRAL PACIFIC ARE FORECAST TO BE PULLED INTO THE HIGHER
LATITUDES IN THE COMING DAYS AROUND THE NE PACIFIC HIGH...A HIGHER
AMPLITUDE PATTERN IS FAVORED.  THEREFORE...A HIGHER PERCENTAGE OF
THE 06Z GEFS MEAN HAS BEEN USED TOGETHER WITH A SMALLER PERCENTAGE
OF THE 00Z EC ENSEMBLE.  THIS HAS ALSO TAKEN INTO ACCOUNT THAT THE
FORECAST TRACK OF TROPICAL STORM ERIKA UP THE FLORIDA PENINSULA IS
MORE IN LINE WITH THE 06Z GFS/GEFS FORECASTS.

...SENSIBLE WEATHER HIGHLIGHTS...

OUT WEST...MOISTURE IS EXPECTED TO MOVE INTO THE PACIFIC NORTHWEST
WITH COOL TEMPERATURES AS THE UPPER TROUGH AMPLIFIES.  SOME
MONSOONAL MOISTURE IS SEEN OVER THE SOUTHERN ROCKIES.  TROPICAL
STORM ERIKA IS FORECAST TO TRACK INTO FLORIDA NEXT WEEK.  IT
APPEARS THAT THE HIGHEST QPF WILL FALL EAST OF THE TRACK.
MOISTURE IS ALSO EXPECTED TO LINGER NEAR THE SE US COAST WHERE A
FRONT GRADUALLY DISSIPATES.

KONG

$$




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