Prognostic Meteorological Discussion
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FXAK02 KWNH 271825
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ALASKA EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
224 PM EDT TUE JUN 27 2017

VALID 12Z SAT JUL 01 2017 - 12Z WED JUL 05 2017

GENERALLY GOOD AGREEMENT EXISTS IN THE MEDIUM RANGE PERIOD FOR
ALASKA, BUT ESPECIALLY EAST OF 160W (MOST OF THE STATE). NOT
UNSURPRISINGLY, THIS IS WHERE AN UPPER HIGH IS FORECAST TO MEANDER
THROUGH THE PERIOD, NUDGING IN FROM THE NORTHEAST AND DRIFTING
THROUGH THE EASTERN INTERIOR. TO THE WEST, AN UPPER LOW OVER THE
BERING SEA SHOULD WOBBLE IN PLACE WITH SMALLER SCALE SHORTWAVES
ROTATING AROUND IT, SUPPORTING WEAK SURFACE FRONTS. ALSO, AN UPPER
LOW INITIALLY IN THE GULF WILL MOVE EASTWARD BUT LINGERING
RELATIVE LOWER HEIGHTS WILL REMAIN STRETCHED ACROSS THE GULF. MUCH
FARTHER SOUTH, AN UPPER HIGH NORTH OF HAWAI`I WILL SQUEEZE THE JET
BETWEEN THERE AND THE ALEUTIANS, WHICH MAY CARRY A SYSTEM EASTWARD
THEN NORTHEASTWARD TOWARD THE SOUTHERN GULF NEXT WEEK (MUCH MORE
UNCERTAINTY HERE AND WAS NOT ABOUT TO JUMP ON THE STRONGER GFS
THIS FAR OUT).

A BLEND OF THE 12Z GFS WITH THE 00Z ECMWF/CANADIAN AND 00Z
NAEFS/ECENS MEAN OFFERED A GOOD STARTING POINT TO THE FORECAST
MOSTLY IN LINE WITH CONTINUITY. UPPER RIDGING WOULD SUPPORT NEAR
TO ABOVE AVERAGE TEMPERATURES OVER THE INTERIOR WITH NEAR/BELOW
AVERAGE TEMPERATURES OVER THE PANHANDLE AND ALEUTIANS DUE TO THE
TROUGHING. PRECIPITATION WILL FOCUS ALONG SOUTHCENTRAL (MOSTLY
FAVORED COASTAL AREAS) INTO THE PANHANDLE BUT ALSO MOSTLY
ALONG/SOUTH OF THE ALASKA RANGE THROUGH THE COPPER VALLEY JUST
AROUND THE UPPER HIGH WHERE AFTERNOON CONVECTION IS POSSIBLE AS
LIFTED INDEX VALUES LINGER NEAR/BELOW ZERO.


FRACASSO


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