Winter Storm Warning 16, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
409 AM AKST FRI NOV 8 2013

.SYNOPSIS...
ALOFT... A VERY DEEP LONG WAVE TROUGH OVER THE
RUSSIAN FAR EAST AND NW PACIFIC WILL PROGRESS EAST TO WESTERN
ALASKA SUN AND OVER MAINLAND ALASKA SUN NIGHT. VERY STRONG SW FLOW
AHEAD OF THE TROUGH IS CARRYING SEVERAL STRONG SHORTWAVES AND
THEIR ATTACHED SURFACE LOWS RAPIDLY NE ACROSS THE BERING SEA AND
NORTHERN ALASKA THROUGH SUN. GIVEN THE SW FLOW THIS WILL CAUSE
HEAVY PRECIPITATION OVER MOST OF NORTHERN ALASKA FROM THE BROOKS
RANGE SOUTH OF THE BETWEEN TONIGHT AND SUN ALONG WITH VERY STRONG
SW WINDS.

ANOTHER STRONG SHORT WAVE AND SURFACE LOW COULD IMPACT THE WEST
COAST OF ALASKA MON NIGHT AND TUE...BUT MUCH UNCERTAINTY ABOUT THAT.

850 MB TEMPERATURES -8 TO -14C RISING TO NEAR FREEZING ALONG THE
WEST COAST THIS AFTERNOON...OVER SW INTERIOR FRI NIGHT...AND OVER
REMAINDER SOUTHERN INTERIOR SAT. AS A RESULT SNOW WILL CHANGE TO
RAIN OVER WEST COAST THIS AFTERNOON...WITH FREEZING RAIN OVER THE
SW INTERIOR FRI NIGHT CHANGING TO RAIN SAT...AND TO FREEZING RAIN
OVER THE SOUTHERN INTERIOR FROM FAIRBANKS WEST SAT AND SAT NIGHT.
THIS COULD BE A SIGNIFICANT FREEZING RAIN EVENT IN ZONES 221...222
AND 225 SAT AND SAT NIGHT. STRONG COLD AIR ADVECTION WILL SWEEP
ACROSS THE WEST COAST/WESTERN INTERIOR SAT NIGHT AND ACROSS THE
EASTERN INTERIOR SUN CHANGING PRECIPITATION BACK TO SNOW.

SURFACE...
A STRONG LOW NEAR WRANGEL ISLAND WILL PERSIST INTO SUN. AN
OCCLUDED FRONT STRETCHING FROM THIS LOW TO ALONG THE WEST COAST OF
ALASKA WILL MOVE TO BARROW TO DENALI BY 3PM FRI THEN DISSIPATE N
OF THE ARCTIC COAST FRI NIGHT. SNOW SHOWERS ALONG THIS FRONT WILL
BECOME SCATTERED AS IT MOVES EAST TODAY AND DIMINISH TONIGHT.
SE WINDS 30KT AHEAD OF THE FRONT WILL DECREASE TODAY AND TURN SW
20KT WEST OF THE FRONT. HEAVY SURF WILL CONTINUE ALONG THE WEST
COAST TODAY WITH THE WINDS TURNING SW.

A SECOND STRONG LOW IN THE SW BERING WILL MOVE TO 100 NM WEST OF
GAMBELL AS A 986 MB LOW BY 3PM FRI AND THEN DISSIPATE NEAR POINT
HOPE BY 3AM SAT. S GALES JUST E OF THIS LOW WILL SPREAD INTO THE
WEST COAST THIS AFTERNOON AND TURN SW TONIGHT. THIS WILL CAUSE SEA
LEVELS TO BEGIN RISING TONIGHT FROM THE BERING STRAIT SOUTH.
THIS WILL PUSH SIGNIFICANT PRECIP INTO THE WEST COAST THIS
AFTERNOON AND WESTERN INTERIOR TONIGHT. COULD SEE SEVERAL INCHES
OF SNOW BEFORE TURNING TO RAIN ALONG THE WEST COAST...WITH 2-6 IN
THE WESTERN INTERIOR...HEAVIEST SOUTH SLOPES OF THE BROOKS.

A 3RD LOW WILL MOVE TO THE CENTRAL BERING AS A 978 MB LOW BY 3AM SAT
AND TO NEAR POINT HOPE AS A 975 MB LOW BY 3PM SAT AND TO 100 NM NE
OF BARROW AS A 971 MB LOW BY 3AM SUN AND THEN 300 NM NORTH OF
BARTER ISLAND BY 3PM SUN. EXPECT SW GALES WITH THIS STORM...WITH
STORM FORCE WINDS SOUTH OF THE BERING STRAIT. THIS IS EXPECTED TO CAUSE
MAJOR COASTAL FLOODING FROM THE BERING STRAIT SOUTH TO THE YUKON
DELTA SAT THROUGH SUN. WITH SHORTER DURATION OF WINDS AND MUCH SHORTER
FETCH EXPECT HEAVY SURF ZONE SW FACING COAST OF 207 SAT INTO SUN.
ANOTHER FRONT WITH THIS LOW WILL SPREAD RAIN AND SNOW INTO THE
WEST COAST AND MORE HEAVY SNOW INTO THE NORTHERN INTERIOR SAT AND
SAT NIGHT. EXPECT SNOW CHANGING TO FREEZING RAIN IN THE WESTERN
INTERIOR AND CENTRAL INTERIOR SAT.

&&

.DISCUSSION...
MODELS HAVE SIMILAR SOLLUTIONS 500 MB THROUGH SUN. AT THE SURFACE
MODELS SIMILAR SOLLUTIONS THROUGH 3PM SAT...THEN GFS FASTER THAN
NAM AND ECMF ON MOVEMENT OF LOW ACROSS ARCTIC COAST. GIVEN VERY
PROGRESSIVE FLOW PATTERN FAVOR THE FASTER GFS PATTERN...BUT SINCE
THE SLOWER NAM AND ECMF SOLLUTIONS WOULD CREATE WORSE FLOODING ON
WEST COAST WILL LINGER STRONGER WINDS THERE AS A PRECAUTION. AS A
RESULT WILL CONTINUING COASTAL FLOODING LONGER AND WORSE THAN GFS
MIGHT INDICATE.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...
HIGH SURF ALL WEST COAST ZONES THROUGH SUN.
MAJOR COASTAL FLOODING EXPECTED SAT THROUGH SUN ZONES 211..212...214
ANOTHER POSSIBLE COASTAL FLOOD ALL WEST COAST MON NIGHT AND TUE
AND ALONG WESTERN ARCTIC COAST TUE.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FOR AKZ209-AKZ211-AKZ213-AKZ214.

HIGH SURF ADVISORY FOR AKZ207-AKZ211-AKZ212-AKZ213-AKZ214.

WINTER STORM WARNING FOR AKZ206-AKZ208-AKZ210-AKZ212-AKZ216-
AKZ217-AKZ218-AKZ219.

COASTAL FLOOD WATCH FOR AKZ211-AKZ212-AKZ214.

WINTER STORM WATCH FOR AKZ220-AKZ221-AKZ222-AKZ225-AKZ227.

HEAVY FREEZING SPRAY WARNING FOR PKZ215-PKZ230.

GALE WARNING FOR PKZ200-PKZ210-PKZ215-PKZ220-PKZ225-PKZ230.

BRISK WIND ADVISORY FOR PKZ235-PKZ240-PKZ245.
&&

JB NOV 13