Brisk Wind Advisory 20, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
1227 PM AST WED JAN 24 2007

.DISCUSSION...
MODELS ARE IN PRETTY GOOD AGREEMENT TODAY. ALL MODELS SUGGESTING
BIG CHANGE IN OVERALL PATTERN BY END OF WEEK. CURRENTLY...COLD UPPER
LEVEL TROUGH OVER MOST OF MAINLAND ALASKA BUT LARGE BLOCKING RIDGE
FORMING OVER WESTERN CANADA. UPPER LEVEL LOW ASSOCIATED WITH
TROUGH WILL MOVE EASTWARD AND THEN RECEDE NORTHWARD ON THURSDAY
MORNING GIVING WAY TO LARGE UPPER LEVEL RIDGE BUILDING IN OVER
MAINLAND ALASKA THROUGH THURSDAY.

AS THE UPPER LEVEL RIDGE CONSUMES NORTHERN ALASKA BY THURSDAY
NIGHT...MODERATE SOUTHERLY FLOW WILL DEVELOP OVER CENTRAL ALASKA.
THE FLOW APPEARS AS OF NOW NOT TOO BE COMPLETELY SOUTHERLY DUE TO
EMBEDDED SHORT WAVES TRAVERSING AROUND THE RIDGE. THIS MAY BE
ENOUGH TO KEEP THE TEMPERATURES IN THE VALLEY OF CENTRAL ALASKA
BELOW THE FREEZING MARK ALTHOUGH HIGHER TERRAIN WILL LIKELY SPIKE
ABOVE TOWARDS THE END OF WEEKEND. THE LARGE UPPER LEVEL BLOCKING
HIGH WILL REMAIN OVER THE AREA THROUGH THE END OF NEXT WEEK.

THE UPPER LEVEL RIDGE BUILDING IN OVER THE CENTRAL MAINLAND
WILL DRASTICALLY INCREASE THE HEIGHTS...MEANING THAT THE VALLEY
LOCATIONS WILL RADIATE OUT NICELY DUE TO MOSTLY CLEAR SKIES AND
THE HIGHER TERRAIN WILL BE GREATLY WARMER WHICH WILL LEAD TO VERY
STEEP INVERSIONS FOR THE NEXT WEEK.

THE NEXT SYSTEM TO IMPACT NORTHERN ALASKA WILL BE THE NORTH
PACIFIC LOW JUST SOUTH OF THE ALEUTIANS. THIS LOW IS PUSHING VERY
WARM AIR NORTHWARD AND A PORTION OF ITS ENERGY WILL BREAK OFF AND
SPREAD NORTH ALONG WEST COAST TO NORTON SOUND BY THURSDAY NIGHT.
ANOTHER LOW WILL TREK JUST BEHIND THAT ONE AND SPREAD MOISTURE
FURTHER WESTWARD WHICH WILL BE GOOD FOR THE SEWARD PENINSULA TO
RECEIVE SOME SNOW FROM THIS SYSTEM ON SATURDAY AS IT APPEARS NOW.

WINDS WILL INCREASE IN THE ALASKA RANGE ON THURSDAY NIGHT AHEAD OF
THE BUILDING RIDGE. HOWEVER THE WINDS AT THIS TIME APPEAR TO BE
SUB-WARNING CRITERIA BUT IT LIKELY THAT THERE WILL BE SOME WIND
ADVISORIES POP UP FOR THURSDAY NIGHT AND FRIDAY. WINDS WILL COME
UP IN ANTICIPATION OF THE NORTH PACIFIC LOW FOR SAINT LAWRENCE
ISLAND AREA ON THURSDAY AND CONTINUE THROUGH FRIDAY.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BRISK WIND ADVISORY FOR PKZ210.
&&

CF JAN 07