Winter Storm Warning 7, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
339 AM AKST THU FEB 12 2009

.DISCUSSION...
THE PATTERN CHANGE TO A MORE ACTIVE AND PROGRESSIVE PATTERN IS
UNDERWAY AND WILL CONTINUE INTO THE MEDIUM RANGE.

A 970 MB LOW NEAR 52N AND THE DATELINE WILL BE THE MAIN
SYSTEM TO IMPACT NORTHERN AK.  THE LOW WILL DEEPEN TODAY AS IT
TRACKS OFF TO THE ENE. THE FRONTAL SYSTEM ASSOCIATED WITH THE LOW
WILL MOVE OVER SAINT LAWRENCE ISLAND AND THE BERING SEA COAST LATE
TODAY...AND NORTH TO THE CHUKCHI SEA COAST LATE TON AND FRI AS THE
LOW BEGINS TO WEAKEN AND PUSHES TOWARD THE WEST COAST. STILL SOME
MODEL DIFFERENCES NOTED ON JUST WHERE THE LOW WILL BE FOUND BY 00Z
SAT. THE GFS TAKES THE LOW INTO BRISTOL BAY WITH A SECONDARY
CENTER FURTHER NORTH OVER NORTON SOUND. THE ECMWF IS SLOWER AND
TAKES THE LOW CENTER TOWARD NORTON SOUND BY SAT AFTERNOON. MODELS
ARE STRUGGLING A BIT AS THERE IS A STRONG DOWNSTREAM RIDGE ACROSS
THE EASTERN INTERIOR AND ADDITIONAL ENERGY EXPECTED TO SLIDE
ACROSS THE ALEUTIANS. IN ANY CASE...IT LOOKS LIKE BLIZZARD
CONDITIONS ARE A GOOD BET ACROSS ST LAWRENCE ISLAND AND ALONG
PARTS OF THE BERING SEA COAST. BLOWING SNOW ISSUES POSSIBLE
FURTHER NORTH ALONG THE NW COAST ON FRI.

MOST OF THE INTERIOR WILL BE IN A CHINOOK FLOW AND DRY.  SOME LIGHT
SNOW MAY MAKE IT AS FAR EAST AS THE WESTERN INTERIOR...BUT THE
REMAINDER OF THE INTERIOR SHOULD HAVE STRONG ENOUGH DOWNSLOPE FLOW
TO REMAIN DRY.  BY LATE THURSDAY NIGHT THERE MAYBE ENOUGH WIND IN
THE AK RANGE PASSES FOR BORDERLINE WIND ADVISORIES.  THE SOUTHERLY
WIND MAY ALSO BECOME STRONG ENOUGH FOR SOME BLOWING SNOW ISSUES
IN THE PASSES OF THE EASTERN BROOKS RANGE...BUT TEMPS SHOULD
MODERATE ENOUGH TO MITIGATE ANY WIND CHILL CONCERNS. TEMPERATURES
ACROSS THE INTERIOR WILL CONTINUE TO MODERATE...WITH TEMPS
CLIMBING INTO THE 20S IN THE HILLS AND WELL ABOVE ZERO IN MOST OF
THE VALLEYS ON FRI.

OVER THE WEEKEND...THE LOW SHOULD CONTINUE TO LIFT OUT TO THE
NORTHEAST AS THE EASTERN INTERIOR RIDGE GETS SQUASHED AND SHUNTED
OFF INTO CANADA. ANOTHER DEEP LOW IS EXPECTED TO TRACK FROM THE
ALEUTIANS AND INTO THE GULF BY MONDAY.  THIS LOW MAY SPREAD SOME
SNOW BACK INTO PARTS OF THE WEST COAST SUN AND SUN NIGHT AND AS THE
FRONTAL BOUNDARY PUSHES EAST IT MAY PUSH SOME COLDER AIR AND A SHOT
OF SNOW ACROSS MUCH OF THE INTERIOR MON AND MON NIGHT. THE
PATTERN LOOKS TO REMAIN PROGRESSIVE WITH YET ANOTHER LOW MOVING
OFF THE KAMCHATKA EARLY NEXT WEEK THAT MAY AFFECT PARTS OF
NORTHERN AK BY THE MIDDLE OF NEXT WEEK...BUT SIGNIFICANT DEPTH AND
TIMING DIFFERENCES ARE NOTED.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FOR AKZ225.

WINTER STORM WARNING FOR AKZ209-AKZ210-AKZ212.

BLIZZARD WARNING FOR AKZ211-AKZ213-AKZ214.

WINTER WEATHER ADVISORY FOR AKZ206-AKZ215-AKZ216-AKZ218.

GALE WARNING FOR PKZ200-PKZ210-PKZ225.

BRISK WIND ADVISORY FOR PKZ200-PKZ220-PKZ225-PKZ230.
&&

CF FEB 09