FXAK69 PAFG 271339 CCA
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION...COR
NATIONAL WEATHER SERVICE FAIRBANKS AK
428 AM AKST FRI NOV 27 2009

.DISCUSSION...
AN ACTIVE PATTERN TO CONTINUE INTO THE MIDDLE OF NEXT WEEK WITH THE 
MEAN TROUGH POSITIONED IN THE VCNTY OF THE DATELINE AND A RIDGE IN 
THE NORTHEAST PACIFIC THAT WILL EXTEND INTO WESTERN CANADA BY EARLY 
NEXT WEEK.  THIS WILL KEEP MOST OF NORTHERN AK IN A LOW HEIGHT 
SOUTHERLY FLOW.  MODELS ARE IN REASONABLY GOOD AGREEMENT ON A STRONG 
BERING SEA STORM THAT HAS THE POTENTIAL OF PRODUCING BLIZZARD 
CONDITIONS ALONG PARTS OF THE WEST COAST AND A STRONG CHINOOK IN THE 
INTERIOR.  

SURFACE...A 980 MB LOW IN THE COOK INLET WILL LIFT NORTH TODAY AND 
GRADUALLY WEAKEN...AND IS EXPECTED TO END UP IN A MUCH WEAKENED 
STATE ALONG THE NORTH SLOPE ON SATURDAY.  A SECOND LOW CURRENTLY 
WELL SOUTH OF THE CENTRAL ALEUTIANS WILL LIFT NORTHEAST AND INTO THE 
NORTHERN GULF OF AK ON SAT. A WEAK LOW CURRENTLY NEAR JAPAN IS 
EXPECTED TO MOVE OFF TOWARD THE SOUTHERN ALEUTIANS SATURDAY AND INTO 
THE SOUTHERN BERING SEA AS A MAJOR STORM SYSTEM ON SUNDAY. THIS IS 
THE NEXT SYSTEM THAT HAS THE POTENTIAL OF PRODUCING SOME HIGH IMPACT 
WEATHER ON PARTS OF NORTHERN AK. ANOTHER STORM...THE REMAINS OF 
SUPER TYPHOON NIDA...ARE EXPECTED TO TRACK MUCH FURTHER SOUTH 
MID-LATE NEXT WEEK. AT THIS TIME IT DOES NOT LOOK LIKELY THAT THIS 
STORM WILL HAVE ANY MAJOR IMPACTS ON OUR WEATHER.

INTERIOR...CHINOOK FLOW WILL GRADUALLY WEAKEN TODAY. UNFORTUNATELY
THERE IS A LACK OF MESONET DATA FROM THE USUAL WINDY SPOTS IN THE
AK RANGE...BUT BASED ON THE PROGGED WIND SPEEDS AT 850-700 MB AND
THE SURFACE PATTERN AND WINDS ALOFT ON THE TALKEETNA WIND PROFILER 
IT WOULD BE REASONABLE TO SURMISE THAT THERE ARE ADVISORY LEVELS
WINDS AT ANTLER CREEK AND IN PASSES WEST OF THE TOK OFF. THE WIND
SHOULD GRADUALLY DIMINISH FROM WEST TO EAST DURING THE DAY. AS THE
SURFACE LOW BEGINS TO TRACK NORTH TODAY THERE SHOULD BE AREAS OF
SNOW FROM PARTS OF THE UPPER KUSKOKWIM VALLEY NORTH TO UPPER
KOYUKUK VALLEY. THE HEAVIEST SNOWFALL TOTALS ARE EXPECTED ACROSS
ZONE 219 FROM ALLAKAKET WEST...WITH SUB-ADVISORY CRITERIA
SNOWFALL ELSEWHERE. WILL KEEP THE WINTER WEATHER ADVISORY FOR ZONE
219 FOR TODAY AND TONIGHT...BUT WILL UPDATE THE ADVISORY TO
MENTION THAT THE HIGHEST TOTALS WILL BE ACROSS THE WESTERN HALF OF
THE ZONE.

THE NEXT STORM SYSTEM THAT DEVELOPS IN THE SOUTHERN BERING SEA LOOKS 
TO HAVE MUCH BETTER SUPPORT SURFACE AND ALOFT FOR A STRONG CHINOOK 
IN THE ALASKA RANGE. BOTH THE GFS AND ECMWF HAVE 70 KT WINDS
ACROSS THE AK RANGE AT 700 MB BY MON NIGHT. THINGS COULD CERTAINLY
CHANGE IN TIME AS THE LOW IS CURRENTLY STILL BACK NEAR JAPAN...BUT
THIS NEXT SYSTEM WILL NEED TO BE MONITORED CLOSELY THIS WEEKEND AS
IT LOOKS FAVORABLE FOR A HIGH WIND EVENT.

MOST OF THE CENTRAL AND EASTERN INTERIOR WILL REMAIN MAINLY DRY
FOR THE NEXT SEVERAL DAYS...BUT THE AFORE MENTIONED LOW THAT LIFTS
INTO THE NORTHERN GULF TO NEAR YAKUTAT ON SUNDAY MAY WRAP A LITTLE
MOISTURE INTO PARTS OF THE INTERIOR. THE CHINOOK ENDS AND THE
FLOW BECOMES LIGHT AND PERHAPS BRIEFLY WESTERLY ON SUNDAY WITH
SOME COLD AIR ADVECTION...AND THIS COULD PRODUCE SOME AREAS OF
LIGHT SNOW OR FLURRIES ON SUNDAY ACROSS MUCH OF THE INTERIOR.

SHOULD ALSO MENTION THAT TEMPS ARE A MAJOR CHALLENGE TODAY...AND
HAVE SEEN SOME DRAMATIC TEMP RISES OVERNIGHT. TEMPS AT NENANA
JUMPED FROM 3 ABOVE TO 23 IN ONE HOUR! MOST OF THE COLD AIR HAS
BEEN SCOURED OUT OF THE VALLEYS LOCALLY...BUT TEMPS STILL WELL
BELOW ZERO ON THE YUKON FLATS. 

WEST COAST...AS THE WEEKEND APPROACHES ALL EYES WILL BE ON THE NEXT 
PACIFIC SYSTEM. BY 12Z MONDAY THE GFS AND ECMWF HAVE BEEN
REASONABLY CONSISTENT THE LAST SEVERAL RUNS AND HAVE THE LOW
CENTER ABOUT 200 MILES WEST OF THE PRIBILOF ISLANDS. THE GFS IS
ABOUT 10 MB DEEPER THAN THE ECMWF. THERE IS SOME ENSEMBLE SPREAD
ON BOTH THE DEPTH AND LOCATION OF THE LOW...BUT ALL MODELS AND
ENSEMBLE MEMBERS AS WELL AS THE CANADIAN AND UKMET HAVE A STRONG
STORM SYSTEM. IF ALL THIS PANS OUT THERE WILL BE STORM FORCE WINDS
IN MARINE AREA 210 BY MONDAY MORNING WITH DEVELOPING GALES ALONG
THE REMAINDER OF THE WEST COAST. THE ONSLAUGHT OF WIND ALONG THE
WEST COAST LOOKS TO BE OUT AHEAD OF THE SNOW...BUT CERTAINLY THE
POTENTIAL FOR BLIZZARD CONDITIONS ON SAINT LAWRENCE ISLAND AND
ALONG THE Y-K DELTA.

NORTH SLOPE...THE SURFACE TROUGH ALONG THE NORTH SLOPE THAT IS 
RESPONSIBLE FOR LIGHT SNOW ALONG THE NORTHERN ARCTIC COAST WILL
LIFT NORTH THIS MORNING WITH LIGHT SNOW TAPERING TO FLURRIES. AS
THE SURFACE LOW IN THE INTERIOR LIFTS NORTH SNOW SHOULD DEVELOP
ALONG MUCH OF THE NORTHERN AND WESTERN ARCTIC COAST TONIGHT AND
CONTINUE AT LEAST INTO SATURDAY MORNING. LOCAL ACCUMULATIONS OF A
COUPLE OF INCHES ARE EXPECTED.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...GALE TO STORM FORCE E-NE
WIND EXPECTED MONDAY WITH GALES SPREADING NORTH OF THE BERING
STRAIT BY MONDAY NIGHT. THE COVERAGE OF SEA ICE LOOKS SUFFICIENT
TO GREATLY LIMIT THE POTENTIAL FOR HIGH SEAS AND COASTAL FLOODING.
SEAS IN EXCESS OF 20 FEET ARE EXPECTED IN THE OPEN WATER WEST AND
SOUTH OF SAINT LAWRENCE ISLAND. 

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FOR AK225-AKZ226.

WINTER WEATHER ADVISORY FOR AK219. 

HEAVY FREEZING SPRAY WARNING FOR PKZ210.

SMALL CRAFT ADVISORY FOR PKZ210.

BRISK WIND ADVISORY FOR PKZ220. 

&&

$$

CB NOV 09