Hail in Alaska, June 22, 2007

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
231 PM ADT FRI JUN 22 2007

.DISCUSSION...
ALOFT...LOW 450 MILES NORTH OF BARTER ISLAND WITH TROUGH TO 5480
METER LOW OVER SOUTHWEST ALASKA. THE LOW OVER THE HIGH ARCTIC WILL
DRIFT NORTH TO 80 NORTH LATITUDE AND WEAKEN MON AM WHILE THE
SOUTHWEST ALASKA LOW WILL WEAKEN INTO A TROUGH FROM BARROW TO KING
SALMON AT THE SAME TIME. SHORT WAVE ENERGY ON NORTHEAST SIDE OF
SOUTHWEST ALASKA LOW WILL DRIFT NORTHEAST OVER ZONE 221 225 AND
222 THIS EVE AND OVER ZONE 220 218 LATE TONIGHT AND SAT AM THEN
CONTINUE INTO CANADA. RIDGE OF HIGH PRESSURE OVER EASTERN INTERIOR
ALASKA DRIFTING EAST OVER THE YUKON AND NORTHWEST TERRITORIES OF
CANADA. RESULTING SOUTH FLOW OVER EASTERN INTERIOR WILL REMAIN
WEAK THROUGH THE WEEKEND. VORTICITY CENTER OVER NORTHERN COAST OF
CHUKOTSK PENINSULA WILL MOVE TO NUNIVAK ISLAND 06Z SUN.

SURFACE...1010 MB LOW NEAR GALENA MOVING TO MCGRATH AT 12Z
BECOMING DIFFUSE. ARCTIC COLD FRONT FROM POINT LAY TO 40 MILES
SOUTH OF BARTER ISLAND MOVING TO NORTHERN FOOTHILLS OF BROOKS
RANGE 12Z SAT AND PERSISTING THROUGH THE WEEKEND. TROUGH ALONG 75
NORTH LATITUDE MOVING EAST SOUTHEAST REACHING BARROW AT 12Z SAT
AND FROM WAINWRIGHT TO BARTER ISLAND 00Z SUN. THERMAL TROUGH FROM
60 MILES NORTH OF BETTLES TO EAGLE WITH SECOND TROUGH FAIRBANKS TO
NORTHWAY. LOW OVER NORTHERN CHUKOTSK PENINSULA AT 1004 MB MOVING
TO NUNIVAK ISLAND 12Z SUN AT 1000 MB.

MODELS...GFS AND WRF FAIRLY SIMILAR THROUGH SHORT TERM. IN MEDIUM
TERM GFS AND ECMWF QUITE CLOSE THROUGH 12Z THU.

NORTH SLOPE...AS ARCTIC COLD FRONT DRIFTS SOUTH TOWARD BROOKS
RANGE SOME DRYING MAY OCCUR TEMPORARILY ACROSS THE COASTAL AREAS
OVERNIGHT...THOUGH THE SURFACE TROUGH MOVING IN FROM THE NORTH SAT
WILL BRING MORE CLOUDS AND LIKELY SOME PRECIPITATION EITHER AS
DRIZZLE OR NIGHTTIME FREEZING DRIZZLE OR FLURRIES AS TEMPS WILL
CONTINUE TO COOL. AS CHUKOTSK COAST LOW MOVES SOUTH TONIGHT HIGH
PRESSURE WILL BUILD OVER THE NORTH CHUKCHI SEA CAUSING MARINE
WINDS TO INCREASE IN ZONES 225 AND 230 SAT.

WESTERN ALASKA...AROUND UPPER LOW AS SURFACE LOW...EXPECT A LOT OF
SHOWERS TONIGHT DIMINISHING TO SCATTERED SATURDAY AND LINGERING
AS SCATTERED SHOWERS INTO SUNDAY. ALSO SHOWERS SAT AND SAT EVE
MAINLY 213 AND 214 DUE TO LOW OVER NORTHERN CHUKOTSK PEN MOVING
SOUTH...AND SMALL CRAFT WINDS TONIGHT AND SAT AM MARINE ZONE 210
IN ADVANCE OF LOW. OVERALL TEMPS REAMING COOL AS AREA WILL BE
UNDER TROUGH ALOFT. AS HIGH BUILDS IN OVER CHUKCHI SEA...NORTH
WINDS INCREASING THROUGH BERING STRAIT SAT NIGHT.

CENTRAL AND EASTERN INTERIOR...EXPECT SCATTERED THUNDERSTORMS
THIS PM OVER ZONES 220 222 223 224 AND 226 WITH ISOLATED OVER THE
REMAINDER OF THE AREA. SOME THUNDERSTORMS MAY LAST THROUGH THE
NIGHT AS THE SHORT WAVE ENERGY MOVES NORTHEAST. SHOWERS OVER
ZONES 221 AND AT LEAST SOUTHWEST PORTION OF 219 DUE TO PROXIMITY
TO UPPER LOW CIRCULATION. SMOKE OVER ZONE 225 BEING PULLED NORTH
FROM SOUTH CENTRAL ALASKA FIRES...MAY CONTINUE INTO SAT AS LIGHT
SOUTH FLOW CONTINUES. LIGHT SOUTHERLY FLOW AT UPPER LEVELS IS NOT
EXPECTED TO SUPPRESS CONVECTION MUCH ON SATURDAY BUT OVERALL
EXPECT LESS THUNDERSTORMS AS THE BEST DYNAMICS MOVE INTO CANADA.
MAXIMUM TEMPS OVERALL A BIT COOLER NEXT FEW DAYS AS LOW- LEVEL
COOL ARI FROM SOUTHWEST LOW GETS PULLED IN...EXPECT FEW IF ANY
READINGS ABOVE 80 EXCEPT YUKON FLATS.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE.

&&

.FIRE WEATHER...SOME WIND OVER ZONES 226 AND 223 SAT BUT HAVE
DROPPED THE WATCH FOR ZONE 223 AS CONDITIONS WILL NOT BE STRONG
ENOUGH THOUGH ZONE 226 MAY BE CLOSE TO RED FLAG CONDITIONS SO HAVE
CONTINUED WARNING THERE.

&&

.HYDROLOGY...NONE

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FOR AKZ226.

DENSE SMOKE ADVISORY FOR AKZ225.

SMALL CRAFT ADVISORY FOR PKZ210-PKZ225-PKZ230.
&&

JL JUN 07