Wildfire in Alaska, May 28, 2010

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
1233 PM AKDT FRI MAY 28 2010

.DISCUSSION...
CURRENT MODEL RUNS THROUGH 00Z TUE ARE INDICATING GENERALLY
SIMILAR OUTCOMES. UPPER RIDGING OVER THE EASTERN INTERIOR AND THE
SOUTHERN PARTS OF THE WEST COAST WILL PERSIST THROUGH MON...BUT
WITH HEIGHTS FALLING SLOWLY.

WEAK SHORT WAVE TROUGH OVER THE NORTHWEST COASTAL AREAS WILL
WEAKEN A LITTLE AS IT MOVES EASTWARD THROUGH 12Z SAT. THIS
FEATURE IS GENERATING FREEZING PRECIP IN ZONE 202...WHICH WE
EXPECT TO RAPIDLY TAPER OFF DURING THE NEXT FEW HOURS AS THE
SYSTEM MOVES EAST. FREEZING PRECIP HAS ALREADY ENDED AT WAINWRIGHT
AND WILL LIKELY END AT ATKASUK SOON. ACCUMULATED PRECIP AT BARROW
HAS EXCEEDED 0.1 INCH BUT LITTLE OR ICE ACCUMULATION IS BEING
REPORTED ON METAL SURFACES...SO WILL STAY WITH A FREEZING RAIN
ADVISORY WHICH WILL LIKELY END BY LATER IN THE DAY.

UPPER RIDGING IS EXPECTED TO PERSIST ACROSS THE INTERIOR AND
SOUTHERN WEST COAST AREAS THROUGH SUN...BUT WITH HEIGHTS
FALLING A LITTLE. WARM TEMPERATURES ARE EXPECTED TO CONTINUE
IN THE INTERIOR THROUGH SUN. AN UPPER TROUGH DROPPING DOWN
FROM THE NORTHWEST ARCTIC IS EXPECTED TO REACH THE NORTHWEST
COAST AND EXTENDING DOWN TO THE SEWARD PENINSULA BY LATE
SUN NIGHT...DEEPENING SOME AS IT DROPS SOUTHEAST. BY LATE
MON NIGHT THE TROUGH WILL MOVE INTO THE WESTERN INTERIOR...
AND TO A LESSER DEGREE OVER THE CENTRAL INTERIOR. THROUGH 00Z
TUE...BOTH THE EUROPEAN AND THE GFS RUNS AGREE ON THIS TREND AND
THE GFS SOLUTION APPEARS TO BE WELL SUPPORTED BY ITS ENSEMBLE
MEAN. WARM TEMPERATURES WILL LIKELY CONTINUE THROUGH LATER IN THE
WEEK OVER THE EASTERN INTERIOR...ESPECIALLY NEAR THE CANADA
BORDER.

LOOKING AT THE CONVECTIVE PICTURE FOR THIS EVENING...WEAK SURFACE
THERMAL TROUGH AXIS EXTENDS ALONG LINE ANIAK-INDIAN MOUNTAIN-
EASTWARD TO THE CANADA BORDER...WITH WEAK THERMAL LOW CENTER OVER
THE UPPER YUKON VALLEY. AREAS NEAR THE THERMAL LOW WILL LIKELY BE
THE MOST ACTIVE FOR CONVECTION...BUT ISOLATED THUNDERSTORM
ACTIVITY IS POSSIBLE OVER MUCH OF THE INTERIOR. GFS RUN SHOWING
LARGE AREAS OF LIFTED INDEX FROM 0 TO -2 COVERING MUCH OF THE
INTERIOR. CIRRUS SHIELD OVER THE SOUTHEAST INTERIOR HAS REDUCED
MORNING HEATING...BUT THIS CIRRUS IS NOW MOVING OFF TO THE NORTH.
AS OF 2030Z...RADAR AND SATELLITE SHOWING CONVECTION INITIATING
IN SOME SOUTHERN AND EASTERN PARTS OF THE RADAR COVERAGE AREA.

FOR SAT...UPPER RIDGING IS EXPECTED TO SHARPEN EAST-WEST ACROSS
THE SOUTHERN INTERIOR WHICH SHOULD PROVIDE SOME SUPPRESSION OF
CONVECTION IN THAT AREA. LOWEST LIFTED INDEXES ARE OVER THE NORTHEAST
INTERIOR...BEST AREA FOR THUNDERSTORM ACTIVITY WILL LIKELY BE IN
THE NORTHEASTERN INTERIOR/EASTERN BROOKS RANGE NEAR THE THERMAL
TROUGH WHICH IS EXPECTED TO EXTEND FT YUKON-SOUTHEAST OF INDIAN
MOUNTAIN-RUBY. RIDGE AXIS MAY DRIFT A BIT FARTHER NORTHWARD
SUN...BUT NOT FAR ENOUGH TO LOWER CONVECTION POTENTIAL IN THE
NORTHEAST INTERIOR AND EASTERN BROOKS RANGE.

MINIMUM BRISK WINDS IN PKZ210...OTHERWISE NO MARINE ISSUES.

&&

.FIRE WEATHER...
RED FLAG CONDITIONS IN ZONES 220-221-222-223-224-226
EXPECTED THIS AFTERNOON/EVENING AND AGAIN SATURDAY
AFTERNOON/EVENING. RED FLAG FOR ZONE 225 THIS AFTERNOON/EVENING.
MIN RH 15 PERCENT OR LESS EXPECTED IN PARTS OF THESE AREAS.

&&

.HYDROLOGY...
NIL.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY FOR AKZ202.

RED FLAG WARNING FOR AKZ220-AKZ221-AKZ222-AKZ223-AKZ224-AKZ225-AKZ226.

SMALL CRAFT ADVISORY FOR PKZ210.
&&

RF MAY 10