FXAK69 PAFG 201139
AFDAFG
NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
339 AM AKDT SAT SEP 20 2008
.DISCUSSION...
CHANGES WELL UNDERWAY OVER THE FORECAST AREA AS BIG RIDGE ALOFT
OVER THE WESTERN NWT MOVES EAST...ALLOWING LOW ALOFT PRESENTLY
OVER SRN NORTON SOUND TO EXPAND OVER MOST OF THE FORECAST AREA. BY
MON MORNING RIDGE STARTS TO BUILD OVER THE NORTHERN BERING SEA. 
AT THE SURFACE...996 MB LOW SE FORT YUKON MOVING NORTHEAST TO BE
A 999 MB CENTER EAST OF BARTER ISLAND BY 12Z SUN. 1000 MB LOW NEAR
KOYUK DRFTG EAST AND DSPTG SAT NIGHT. WEAK 1014 MB HIGH
DEVELOPING OVER SW ALASKA BY 12Z SUN WITH RIDGE EXTENDING NW INTO
THE BERING STRAIT AND SRN CHUKCHI SEA. DEVELOPING LOW IN THE SW
BERING SEA WILL MOVE TO NEAR ST MATTHEW ISLAND AS A 1009 MB CENTER
BY 12Z MON.
IN THE SHORT TERM...MODELS IN DECENT AGREEMENT ON THE LARGE SCALE
EVOLUTION.
IN THE LONG RANGE...MODELS IN DECENT AGREEMENT ON KEEPING LOW
HEIGHTS BUT LIMITED DYNAMICS OVER NORTHERN ALASKA THRU THIS WEEK
AS HIGH BUILDS OVER CHUKOTKA AND WESTERN CHUKCHI SEA. 00Z ECMWF
SEEMS TO GO OVERBOARD BUILDING THIS HIGH...WITH HEIGHTS AT 574DM
BY SAT MORNING...100 METERS OR MORE HIGHER THAN 12Z RUN OR GFS.
00Z NAEFS ENSEMBLE MEMBERS APPEAR TO OFFER NO SUPPORT AT ALL FOR
SUCH AN UNSEASONABLY STRONG HIGH. 
FOR THE NORTH SLOPE...SOME PRECIP SHOULD MAKE IT OVER THE BROOKS
RANGE AS SFC LOW POPS NORTH. AIRMASS HAS BEEN STEADILY
WARMING...EVEN ATIGUN PASS ABOVE FREEZING NOW. AMS WILL COOL SOME
ON SUN...WITH SNOW LEVELS LOWERING...THOUGH PROBABLY TO TO NEAR
SEA LEVEL. NO SGFNT PRECIP EXPECTED IN WESTERN ZONES. WINDS MOSTLY
REMAINING LIGHT EXPECT PROBABLY EASTERN ZONES SUN PM AS SFC LOW
PULLS AWAY. 
FOR THE WEST COAST...GENERALLY RISING HEIGHTS WILL LIMIT ANY
PRECIP SAT NIGHT AND SUN. LOW MOVING EAST INTO CENTRAL BERING SEA
COULD SPREAD RAIN AS FAR NORTH AS ST LAWRENCE ISLAND AND AS FAR
EAST AS THE YUKON DELTA COAST BY MONDAY MORNING. TEMPS COOL BUT
EXCESSIVELY SO. 
FOR THE INTERIOR...OLD OCCLUSION HAS BEEN RIPPED TO SHREDS.
WIDESPREAD PRECIP HAS FAILED TO MATERIALIZE...WITH ONLY A FAIRLY
NARROW SMALL AREA IN THE NORTH CENTRAL INTERIOR WITH EVEN A TENTH
OF AN INCH OF RAIN. COOL AIRMASS MOVING EWD NEXT 24 HOURS AND
SHOULD BE FIRMLY ENTRENCHED BY MON MORNING. THIS SHOULD BRING
FREEZE THE REMAINING PLACES THAT HAVE NOT HAD ONE THUS FAR THIS
AM. LOW HEIGHTS WILL LIKELY ALLOW FOR SOME SHOWERS BUT NOT MUCH IN
THE WAY OF DYNAMICS FOR ANY SIGNIFICANT SNOW JUST YET.
COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE
&&
.HYDROLOGY...NONE
&&
.AFG WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
RT SEP 08