967
FXAK69 PAFG 062216
AFDAFG
NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
216 PM AKDT SAT SEP 6 2008
DISCUSSION
MODELS IN DECENT AGREEMENT THROUGH FIRST 36 HOURS AND THEN BEGIN
TO DIVERGE THEREAFTER. BIG DIFFERENCE BEING THAT THE NAM CARRIES A
CUTOFF UPPER LEVEL AND SURFACE LOW EASTWARD TO THE GULF OF ALASKA
WHILE THE GFS DOES NOT IDENTIFY THIS FEATURE. THE NAM FLATTENS THE
UPPER LEVEL RIDGE OUT OVER THE ALASKA CANADA BORDER WHILE THE GFS
AND THE ECMWF AMPLIFY THE RIDGE. THIS CREATES THE TROUGH TO DEEPEN
OVER THE WEST COAST AND THEN MOVE EASTERLY.
PREFER THE GFS AND THE ECMWF SOLUTION AT THIS TIME AS DO NOT
EXPECT THE UPPER LEVEL LOW TO BE ABLE TO PUSH THE RIDGE FLAT.
EXPECT CHINOOK WINDS WILL DEVELOP OVER THE CENTRAL INTERIOR ON
SUNDAY. SINCE THE CHINOOK WILL NOT BE THAT STRONG, IT IS POSSIBLE
THAT SOME OF THE PRECIPITATION COULD SPILL OVER TO THE NORTH SIDE
OF THE RANGE SUNDAY AFTERNOON OR EVENING. THE TROUGH MOVES
NORTHWARD TO THE BROOKS RANGE BY SUNDAY NIGHT WHICH WILL ALLOW
UPSLOPE RAINFALL FOR THE NORTHERN INTERIOR.
ONSHORE FLOW OVER THE ARCTIC COAST AND MUCH OF THE WEST COAST WILL
KEEP DENSE FOG CONDITIONS LIKELY FOR TONIGHT THROUGH SUNDAY MORNING.
AS THE LOW MOVES UP INTO THE THE BERING SEA SUNDAY MORNING...THIS
WILL INCREASE THE GRADIENT OVER MOST OF THE WEST COAST WHICH WILL
BE THE CAUSE FOR THE THE MARINE ADVISORIES. A FEW SHOWERS WILL
SPREAD NORTHWARD TO THE SEWARD PENINSULA BY SUNDAY
AFTERNOON...HOWEVER DO NOT EXPECT A BIG RAIN EVENT.
COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE
FIRE WEATHER
NONE.
HYDROLOGY
NONE.
AFG WATCHES/WARNINGS/ADVISORIES
SMALL CRAFT ADVISORY FOR PKZ200-PKZ210-PKZ220-PKZ225-PKZ230.
CF SEP 08
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