High Surf Advisory 7, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
153 PM AKDT TUE SEP 22 2015

.SYNOPSIS...
ALOFT...
THE LONG WAVE TROUGH OVER THE ALCAN BORDER AND EASTERN GULF OF
ALASKA WILL PERSIST THROUGH THU AND THEN MOVE EAST. THE LONG WAVE
RIDGE OVER BERING SEA AND WEST COAST OF ALASKA WILL FLATTEN OUT
THU AND FRI AS A STRONG SHORT WAVE MAKES ITS WAY EAST ACROSS
NORTHERN ALASKA. THE RIDGE WILL SLOWLY REBOUND OVER NORTHERN
ALASKA OVER THE WEEKEND AS A SECOND LONG WAVE TROUGH MOVES EAST
INTO THE BERING. THAT TROUGH WILL PROGRESS EAST OVER MAINLAND
ALASKA NEXT WEEK. THIS MEANS THAT THE SCATTERED SHOWERS WITH THE
FIRST SHORT WAVE TROUGH WILL TAPER OF THROUGH THU WITH DECREASE IN
CLOUDS OVER THE WESTERN INTERIOR. THE STRONG SHORT WAVE WILL BRING
WARMER TEMPERATURES AND RAIN/SNOW SPREADING EAST ACROSS NORTHERN
ALASKA THU AND FRI AND CONTINUING INTO THE WEEKEND. COOLER AND WET
WEATHER WILL RETURN NEXT WEEK.

A WEAK SHORT WAVE TROUGH FROM TOK TO BARTER ISLAND WILL MOVE TO
NORTHWAY ALONG THE ALCAN BORDER BY 4PM WED AND THEN DISSIPATE.
EXPECT SCATTERED SNOW SHOWERS WITH THIS FEATURE.

SNOW LEVELS AT SURFACE ACROSS ALL NORTHERN ALASKA. SNOW LEVEL
RISING TO 3000 FT ALONG WESTERN CAPES TONIGHT...AND TO 3000 FT
ALONG THE WEST COAST AND WESTERN ARCTIC COAST WED. WILL SEE SNOW
LEVELS RISE TO 3-5000 FT ALONG THE WEST COAST...WESTERN NORTH
SLOPE AND WESTERN INTERIOR THU.

SURFACE...
A RIDGE OF HIGH PRESSURE STRETCHING FROM THE BEAUFORT SEA TO
SOUTHWEST ALASKA WILL MOVE TO THE BEAUFORT SEA TO BRISTOL BAY BY
4PM WED...AND THEN TO OVER THE SOUTHEAST INTERIOR BY 4PM THU.
EXPECT PARTIAL CLEARING OF CLOUDS UNDER THIS RIDGE OVER THE
INTERIOR ALONG WITH LOW TEMPERATURES FALLING INTO THE 20S AND
UPPER TEENS AT NIGHT.

A LOW WEST OF WRANGEL ISLAND WILL MOVE TO WRANGEL ISLAND AS A 993
MB LOW BY 4PM WED...AND TO 200 NM NORTHWEST OF BARROW AS A 987 MB
LOW BY 4PM THU. AN OCCLUDED FRONT STRETCHING SE OF THIS LOW WILL
MOVE BY 4AM WED TO THE WESTERN CHUKCHI SEA WITH A WARM FRONT FROM
THE WESTERN BERING STRAIT TO ST MATTHEW ISLAND. BY 4PM WED THE
OCCLUDED FRONT WILL MOVE TO THE LOW TO CAPE LISBURNE WITH A WARM
FRONT FROM CAPE LISBURNE TO THE YUKON DELTA. BY 4AM THU OCCLUDED
FRONT WILL STRETCH FROM THE LOW TO WAINWRIGHT TO NOATAK WITH A
WARM FRONT FROM NOATAK TO THE YUKON DELTA. BY 4PM THU THE
OCCLUDED FRONT WILL STRETCH FROM THE LOW TO BARROW TO AMBLER WITH
A WARM FRONT FROM AMBLER TO ANVIK. BY 4PM FRI THE OCCLUDED FRONT
WILL STRETCH FROM BARTER ISLAND TO NORTHWAY. EXPECT MIXED RAIN AND
SNOW AHEAD OF THE FRONT CHANGING TO RAIN ALONG THE FRONTS. EXPECT
.50-1.00 INCH OF RAIN WITH THE FRONT WITH THE HIGHEST AMOUNTS
ALONG SW FACING SLOPES. SNOW FALL ACCUMULATION WILL BE ABOVE 3000
FEET. WILL SEE SOUTH WINDS 25-35KT ALONG THE WEATHER FRONTS WITH
THE STRONGEST WINDS IN THE SE QUADRANT OF THE LOW.

THIS COULD ELEVATE SEE LEVELS BY 1-2 FEET FROM KIVALINA TO BARROW
FROM WED EVENING THROUGH THU EVENING. AT THIS TIME IT LOOKS MINOR
DUE TO SHORT FETCH LENGTH. COULD SEE HIGH SURF WED NIGHT TO THU
FROM KIVALINA TO POINT HOPE SINCE WINDS WILL BE PUSHING WAVES
ONSHORE. ON THE ARCTIC COAST WITH FLOW OFFSHORE EXPECT NOTHING
MORE THAN MODERATE SURF.

A 985 MB LOW WILL DEVELOP IN THE CENTRAL CHUKCHI SEA BY 4PM THU
WITH AN ARCTIC COLD FRONT FROM THE LOW TO PROVIDENIYA. BY 4AM FRI
IT WILL BE A 987 MB LOW 80 NM WEST OF POINT LAY WITH A COLD FRONT
FROM POINT LAY TO THE YUKON DELTA. BY 4PM FRI THE LOW WILL BE NEAR
UMIAT AS A 990 MB LOW WITH A COLD FRONT FROM ATIGUN PASS TO
DENALI. PRECIPITATION WILL CHANGE BACK TO SNOW WITH THIS ARCTIC
COLD FRONT WITH SEVERAL INCHES OF SNOW POSSIBLE. EXPECT NW WINDS
30-40KT WITH THE FRONT ALONG THE WEST COAST DECREASING TO 20-30KT
INLAND. COULD SEE STRONG GUSTS IN THE INTERIOR FRI WITH THIS.

WITH SEE LEVELS ALREADY ELEVATED IN KOTZEBUE SOUND...THESE NW
WINDS COULD CAUSE HIGH SURF FROM THE BERING STRAIT TO KOTZEBUE
FROM MIDNIGHT THU NIGHT TO FRI PM. THIS WILL NEED TO BE WATCHED
CLOSELY AS IT HAS POTENTIAL FOR DAMAGING SURF AT SHISHMAREF
DEERING AND KOTZEBUE.

&&

.DISCUSSION...
MODELS SHOW SIMILAR SOLUTION THROUGH 4AM THU. THEREAFTER THE NAM
MOVES THE LOW EAST ACROSS THE CHUKCHI SEA FASTER THAN THE GFS. AT
THIS POINT WILL GO WITH THE GFS AS IT AGREES FAIRLY WELL WITH ECMF
THU INTO FRI. AFTER THAT START TO SEE BIGGER DIFFERENCES ON TIMING
AND STRENGTH OF SHORT WAVES SO LOWER CONFIDENCE FROM THE WEEKEND
INTO NEXT WEEK.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...
COULD SEE HIGH SURF WED AFTERNOON TO THU PM FROM KIVALINA TO
POINT HOPE SINCE SOUTH WINDS WILL BE PUSHING WAVES ONSHORE. ON
THE ARCTIC COAST WITH FLOW OFFSHORE EXPECT NOTHING MORE THAN
MODERATE SURF.

WITH SEE LEVELS ELEVATED IN KOTZEBUE SOUND...NW WINDS COULD CAUSE
HIGH SURF FROM THE SHISHMAREF TO KOTZEBUE FROM THU NIGHT TO FRI
NIGHT.

&&

.HYDROLOGY...
RIVERS STEADY NOW AND RISING LATE IN WEEK.
NO FLOODING EXPECTED.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY FOR AKZ207.

SMALL CRAFT ADVISORY FOR PKZ210-PKZ220-PKZ225-PKZ230-PKZ235.

GALE WARNING FOR PKZ225.
&&

JB SEP 15