Blizzard in Alaska, April 6, 2005

NORTH ALASKA FORECAST DISCUSSION
600 AM ADT WED APR 6 2005

.DISCUSSION...
THE MODELS ARE PRETTY SIMILAR IN THE VERY SHORT TERM BUT THEN
BEGIN TO DIFFER SOMEWHAT AT ABOUT 12Z THURSDAY. BOTH MODELS ARE
SIMILAR IN MOVING THE LOW FROM THE GULF OF ALASKA INTO THE YUKON
KUSKOKWIM DELTA ALTHOUGH DIFFERING IN CENTRAL PRESSURES. BUT THE
MODELS ARE BEGIN LOSING SIMILARITIES WITH THE NEXT LOW MOVING INTO
THE GULF OF ALASKA. IT LOOKS LIKE THE ETA MAY BE KEEPING THE LOW
TOO FAR SOUTH AND MUCH TOO WEAK IN TERMS OF CENTRAL PRESSURE.
THERE IS SUFFICIENT COLD AIR IN THE GULF OF ALASKA SO DO NOT QUITE
BELIEVE THE ETA FILLING THE LOW SO FAST.

IN TERMS OF THE THE UPPER LEVEL PATTERN...THE ENCROACHING 500H
RIDGE BUILDING IN FROM THE WEST COAST OF THE LOWER 48 ATTEMPTED TO
BRING IT IN OVER MAINLAND ALASKA FOR A BIT LONGER IN PREVIOUS GFS
MODEL RUNS. HOWEVER ALL MODELS TO ALLOW THE UPPER LEVEL TROUGH
ALONG THE WEST COAST TO GAIN ENERGY AND SHUNT THE UPPER LEVEL
RIDGE OFF INTO CANADA. SO OVERALL...THE MODELS BRING THE TROUGH
OVER MOST OF ALASKA BY THE END OF THE WEEK WITH ONLY MINOR
DIFFERENCES IN THE WAY THE MODELS HANDLE THE OCCASIONAL POKING OF
THE CANADIAN RIDGE CREEPING BACK INTO THE CENTRAL INTERIOR OF THE
STATE.

ARCTIC COAST...AS THE ARCTIC BOUNDARY GETS SHOVED BACK NORTHWARD
TO LIE ALONG THE WESTERN AND ARCTIC COASTS...THE POSSIBILITY FOR A
LITTLE OVERRUNNING EXISTS. THIS MAY PROVIDE SOME SNOW SHOWERS BUT
NOT MUCH OF ANY SIGNIFICANCE. THE TEMPERATURES WILL BEGIN TO
MODERATE ALONG THE ARCTIC COAST AS WELL.

WEST COAST...MUCH THE SAME AS THE ARCTIC COAST. THE ARCTIC
BOUNDARY WILL MOVE OFF THE COAST BY 18Z THURSDAY. THIS WILL
ESSENTIALLY SHUT OFF ANY SNOW THAT MAY FALL. THE TEMPERATURES WILL
MODERATE SOMEWHAT AS WELL BEFORE MORE COLD AIR...THOUGH NOT AS
COLD AS THE PREVIOUS AIR...MOVES BACK SOUTHWARD AGAIN. WINDS WILL
PICK BACK UP AGAIN ALONG THE TIN CITY AREA AS THE WINDS ARE ON THE
INCREASE ONCE AGAIN WITH THE TIGHTENING OF THE PRESSURE GRADIENT.

THE INTERIOR...WILL SEE WARMER THAN AVERAGE TEMPERATURES FOR THE
NEXT SEVERAL DAYS WITH NOT MUCH OF ANY CHANCE FOR PRECIPITATION.
THE UPPER LEVEL RIDGE OVER THE EASTERN PORTION OF THE STATE WILL
KEEP THE MOISTURE OUT AS WELL.

.AFG WATCH/WARNING/ADVISORIES...
PUBLIC...NONE.
MARINE...BRISK WIND ADVISORY...9B.

CF APR 05