Winter Storm Warning 16, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
450 AM AKDT WED AUG 26 2015

.SYNOPSIS...
ALOFT...
THE LONG WAVE TROUGH STRETCHING FROM THE WRANGEL ISLAND TO THE
WESTERN BERING SEA INTO THE NW PACIFIC WILL PROGRESS EAST OVER
MAINLAND AK THU AND THEN PERSIST INTO NEXT WEEK. STRONG SW FLOW
ON THE EAST SIDE OF THE LONG WAVE TROUGH CONTINUES TO PUSH AIR
WITH 3 TIMES THE NORMAL PRECIPITABLE WATER OVER NORTHERN ALASKA.
THIS ADDITIONAL MOISTURE WAS FED INTO THE EAST SIDE OF THE TROUGH
BE A FORMER TYPHOON DISSIPATING THE NW PACIFIC. THIS HIGH MOISTURE
AIR WILL CONTINUE TO CAUSE HEAVY RAIN OVER NORTHERN ALASKA THROUGH
THU WITH SOUTH AND WEST FACING SLOPES GETTING THE HIGHEST AMOUNTS.
SEVERAL STRONG SHORT WAVES AND THEIR ASSOCIATED FRONTAL WAVES WILL
CAUSE ENHANCED RAINFALL THROUGH THU. FROM FRIDAY INTO NEXT WEEK
EXPECT COOL AND WET CONDITIONS...BUT PRECIPITATION WILL NOT BE AS
HEAVY.

A STRONG SHORT WAVE ALONG THE WEST COAST OF ALASKA WILL MOVE TO
ANAKTUVUK TO DENALI BY 4PM WED AND EAST OF THE ALCAN BORDER WED
NIGHT. A STRONG SURFACE FRONTAL WAVE IS ASSOCIATED WITH THIS ALONG
WITH HEAVY RAIN AND SW WINDS GUSTING TO 30 KT.

850 MB TEMPERATURES RANGE FROM 4 TO8C NOW. TEMPERATURES WILL FALL
TO 0C TO -4C OVER NW AK THIS AFTERNOON BEHIND THE COLD
FRONT...WITH THIS COLD AIR SPREADING OVER THE REST OF NORTHERN
ALASKA THU WITH THE COLD FRONT. THIS WILL LOWER THE SNOW LEVEL TO
1000-2000 FEET BEHIND THE COLD FRONT THU.

SURFACE...
A 987 MB LOW 150 NM NORTHWEST OF BARROW WILL MOVE TO 170 NM
NORTHWEST OF BARROW BY 4PM WED...TO 150 NM NORTH OF BARROW BY 4AM
THU...TO 200 NM NORTH OF BARROW BY 4PM THU...AND TO 150 NM NORTH
OF BARROW BY 4PM FRI. GALES FORCE W WINDS IN THE SW QUADRANT OF
THIS LOW WILL MOVE OVER THE ARCTIC COAST FROM BARROW WEST WED
NIGHT AND TO THE EASTERN ARCTIC THU. THIS WILL CAUSE HIGH SURFACE
FROM BARROW WEST TONIGHT AND THU WITH SEA LEVEL RISE OF 1-2 FT.
SINCE THERE IS SEA ICE BETWEEN BARROW AND PRUDHOE BAY DO NOT
EXPECT HIGH WAVES OR ELEVATED SURF EAST OF BARROW. MAY SEE SEA ICE
PUSH ALONG THE COAST FROM PRUDHOE BAY EAST AS A RESULT OF THESE
WINDS BUT ONLY LIMITED SURF DUE TO DAMPENING BY THE SEA ICE.

A A 995 MB FRONTAL WAVE IN THE BERING STRAIT WILL MOVE TO
GALBRAITH LAKE AS A 994 MB LOW BY 4PM WED AND TO INUVIK AS A 991
MB LOW BY 4AM THU. A WARM FRONT EXTENDING EAST OF THIS LOW.
A COLD FRONT EXTENDING SOUTH OF THE LOW WILL MOVE TO ANAKTUVUK
PASS TO DENALI BY 4PM WED...TO OLD CROW TO CIRCLE TO BIG DELTA BY
4AM THU...AND EAST OF THE ALCAN BORDER BY NOON THU. WILL SEE HEAVY
RAIN ALONG THE FRONTAL WAVE AND ALONG THE WARM AND COLD FRONTS.
EXPECT ANOTHER 0.5-1.5 INCHES OF RAIN TO SPREAD EAST ACROSS
NORTHERN ALASKA WITH THIS SYSTEM...WITH THE HEAVIEST AMOUNTS ALONG
SOUTH AND WEST FACING SLOPES. RAIN WILL BECOME LIGHT WEST OF THE
COLD FRONT. EXPECT THIS TO CAUSE FLOODING OF SMALL STREAMS ZONES
208 210 211 212 217 WITH LARGE RIVERS RISING TO HIGH LEVELS BUT
NOT FLOODING. THIS COULD CAUSE SMALL STREAMS TO FLOOD IN STEEP
TERRAIN OF THE INTERIOR SUCH AS SOUTH SLOPES OF THE CENTRAL BROOKS
RANGE...THE WESTERN ALASKA RANGE...AND THE CHENA AND SALCHA
BASINS SO WILL NEED TO KEEP EYE ON THOSE AREAS.

ARCTIC COLD FRONT OVER THE DATELINE WILL MOVE TO JUST EAST OF
BARROW TO NOME TO GAMBELL BY 4PM WED...TO DEMARCATION POINT TO
COLD FOOT TO THE YUKON DELTA BY 4AM THU...TO ARCTIC VILLAGE TO
NORTHWAY BY 4PM THU...THEN CONTINUING EAST. EXPECT RAIN EAST OF
THE FRONT TAPERING OFF TO SCATTERED SHOWERS NORTHWEST OF THE
FRONT. SNOW LEVEL WILL DROP TO 1000-2000 FEET NW OF THE FRONT.
EXPECT 2-6 INCHES OF SNOW ACROSS THE EASTERN BROOKS RANGE TONIGHT
THROUGH LATE THU...HEAVIEST ABOVE 2000 FT. WILL ISSUE WINTER
STORM WATCH FOR ZONE 206. EXPECT 2-4 INCHES IN THE ALASKA RANGE
ABOVE 3000 FT THU-THU NIGHT.

&&

.DISCUSSION...
MODELS INITIALIZE WELL AND SHOW SIMILAR SOLUTION THROUGH THU.
START TO SEE MODELS DIVERGE ON FRI WITH TIMING AND STRENGTH OF
SHORT WAVE TROUGHS BUT ALL MODELS KEEP LONG WAVE TROUGH OVER
MAINLAND ALASKA INTO NEXT WEEK. PREFER THE GFS PRECIP AMOUNTS
WHICH ARE HEAVIER THAN THE NAM ANS ECMF FOR TODAY BUT VERIFY
BETTER AT 06Z.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...
HIGH SURF ZONES 213 AND 207 NOW ENDING.
HIGH SURF 211 AND 212 WILL CONTINUE THROUGH THU.
HIGH SURF ZONES 201 AND 202 FROM THIS AFTERNOON TO 10 PM THU.

MODERATE SURF ZONES 203 AND 204 THU AND THU NIGHT WITH POTENTIAL
FOR ICE RAFTING ONSHORE.

MODERATE SURF ZONE 207 AT SHISHMAREF TONIGHT THROUGH THU.
POTENTIAL FOR HIGH SURF 207 AT SHISHMAREF THIS WEEKEND.

&&

.FIRE WEATHER...
NONE.

&&

.HYDROLOGY...
HAVE HAD 1.0-2.5 INCHES OF RAIN ACROSS THE WEST COAST AND NW
INTERIOR AND .5-1.5 INCHES ACROSS REMAINDER OF AREA FROM BROOKS
RANGE SOUTH. EXPECT ANOTHER 0.5-1.5 INCHES OF RAIN TO SPREAD EAST
ACROSS NORTHERN ALASKA WITH THIS SYSTEM...WITH THE HEAVIEST
AMOUNTS ALONG SOUTH AND WEST FACING SLOPES. RAIN WILL BECOME LIGHT
WEST OF THE COLD FRONT. EXPECT THIS TO CAUSE FLOODING OF SMALL
STREAMS ZONES 208 210 211 212 217 WITH LARGE RIVERS RISING TO HIGH
LEVELS BUT NOT FLOODING. THIS COULD CAUSE SMALL STREAMS TO FLOOD
IN STEEP TERRAIN OF THE INTERIOR SUCH AS SOUTH SLOPES OF THE
CENTRAL BROOKS RANGE...THE WESTERN ALASKA RANGE...AND THE CHENA
AND SALCHA BASINS SO WILL NEED TO KEEP EYE ON THOSE AREAS.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FOR AKZ222.

HIGH SURF ADVISORY FOR AKZ201-AKZ202-AKZ211-AKZ212-AKZ214.

FLOOD WATCH FOR AKZ210-AKZ211-AKZ212.

SMALL STREAM FLOOD ADVISORY ZONES 210 217

WINTER STORM WATCH FOR AKZ206.

SMALL CRAFT ADVISORY FOR PKZ200-PKZ210-PKZ215-PKZ220-PKZ225-
PKZ230-PKZ235-PKZ240-PKZ245.

GALE WARNING FOR PKZ225-PKZ230-PKZ235.

&&

JB AUG 15

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FAIRBANKS AK
734 AM AKDT WED AUG 26 2015

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0733 AM     HEAVY RAIN       MANLEY HOT SPRINGS      64.99N 150.64W
08/26/2015  M1.37 INCH                          AK   CO-OP OBSERVER

            24 HOUR PRECIP MEASUREMENT OF 1.37 INCHES. RIVER GAUGE IS
            UP TO 7.91 AND RISING.

&&

HLIND

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FAIRBANKS AK
1205 PM AKDT WED AUG 26 2015

AKZ204-271500-
EASTERN BEAUFORT SEA COAST-
INCLUDING...KAKTOVIK...FLAXMAN ISLAND
1205 PM AKDT WED AUG 26 2015

...MODERATE SURF CONDITIONS AND SEA ICE PUSH POSSIBLE THURSDAY
AND OVERNIGHT THURSDAY...

A LOW PRESSURE SYSTEM CURRENTLY 200 NM NORTHWEST OF POINT BARROW
WILL LIFT NORTHEAST AND BECOMING ELONGATED THURSDAY FROM NORTH OF
BARROW TO THE EASTERN BEAUFORT SEA AND BANKS ISLAND. THE LOW
PRESSURE SYSTEM WILL STAY ROUGHLY IN PLACE BEFORE LIFTING FARTHER
NORTH FRIDAY.

THE SYSTEM WILL BRING A PERIOD OF STRONG WESTERLY WINDS...UP TO
50 MPH...BEGINNING THURSDAY MORNING THAT WILL CONTINUE BEFORE
BEGINNING TO DIMINISH FRIDAY MORNING. MODERATE SURF CONDITIONS
ARE ANTICIPATED TO DEVELOP THURSDAY INTO FRIDAY HOWEVER...HIGH
SURF CONDITIONS ARE NOT EXPECTED DUE TO SEA ICE TO THE WEST.

THERE IS POTENTIAL FOR SEA ICE TO BE PUSHED ONTO LAND ALONG THE
SHORE AS STRONG WINDS ARE EXPECTED TO PERSIST FOR AN EXTENDED
PERIOD OF TIME. WHEREIN...HEAVY CONCENTRATION OF SHORE-FAST ICE
FROM THIS WINTER SEASON WEST OF KAKTOVIK COULD BREAK AND PUSH
EASTWARD. THE WINDOW OF TIME FOR ICE TO BREAK...TRAVEL
EASTWARD...AND MOVE TOWARDS THE EASTERN BEAUFORT SEA COAST WOULD
BE OVERNIGHT THURSDAY AND FRIDAY MORNING.

THOSE LIVING ON THE EASTERN BEAUFORT SEA COAST SHOULD MONITOR THE
LATEST FORECASTS AND UPCOMING WEATHER STATEMENTS FOR ADDITIONAL
INFORMATION.

ET

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FAIRBANKS AK
129 PM AKDT WED AUG 26 2015

AKZ207-271400-
CHUKCHI SEA COAST-
INCLUDING...POINT HOPE...SHISHMAREF...KIVALINA...ESPENBERG
129 PM AKDT WED AUG 26 2015

...WINDY AND MODERATE SURF CONDITIONS THIS AFTERNOON THROUGH
THURSDAY...

A LOW PRESSURE SYSTEM NORTH OF THE CENTRAL ARCTIC COAST WILL
GRADUALLY MOVE NORTHEAST OVERNIGHT AND TOMORROW. THE SYSTEM WILL
PROMPT NORTHWESTERLY WINDS UP TO 25 KTS THAT WILL PROMOTE MODERATE
SURF CONDITIONS FROM SHISHMAREF TO ESPENBERG THIS AFTERNOON
THROUGH THURSDAY.

LOCAL AREAS ALONG THE COAST MAY SEE MINOR EROSION OF THE SHORE.
THOSE LIVING IN THIS AREA SHOULD MONITOR THE LATEST FORECASTS AND
UPCOMING WEATHER STATEMENTS FOR ADDITIONAL INFORMATION.

ET