Gale Warning 145, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
407 AM AKST THU DEC 17 2015

.SYNOPSIS...
ALOFT...
A LONG WAVE RIDGE OVER WESTERN CANADA AND EASTERN ALASKA WITH A
TROUGH OVER WESTERN ALASKA AND THE GULF OF ALASKA WITH ANOTHER
RIDGE OVER THE BERING AND ANOTHER TROUGH OVER KAMCHATKA. THIS
PATTERN IS PROGRESSIVE WITH THE FIRST LONG WAVE MOVING OVER
MAINLAND ALASKA TODAY THEN THE SECOND LONG WAVE MERGING WITH THE
FIRST LONG WAVE OVER MAINLAND ALASKA THIS WEEKEND. THE LONG WAVE
WILL PERSIST OVER MAINLAND ALASKA THROUGH THE MIDDLE OF NEXT WEEK.
THIS MEANS THAT TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH SAT
AND THEN DROP BELOW NORMAL FROM SUN THROUGH NEXT WEEK.

THERE WILL BE SEVERAL SHORT WAVES MOVING EAST ACROSS NORTHERN
ALASKA THROUGH THE WEEKEND THAT WILL SET OFF PERIODS OF SNOW.

ONE SHORT WAVE STRETCHING FROM WAINWRIGHT TO INUVIK WILL MOVE NE
AND WEAKEN TONIGHT. FLURRIES OR LIGHT SNOW ALONG AND NORTH OF THIS
TROUGH.

A SECOND SHORT WAVE ALONG 170W WILL MOVE TO POINT HOP TO BETHEL BY
3PM THU...POINT LAY TO MCGRATH BY 3AM FRI...TO BARROW TO DENALI BY
3PM FRI...AND TO DEADHORSE TO EAGLE BY 3PM SAT. EXPECT ISOLATED
SNOW SHOWERS ALONG THIS TROUGH THROUGH TONIGHT...BECOMING MORE
SCATTERED TO NUMEROUS FRI AS THE TROUGH MOVES THROUGH THE CENTRAL
AND EASTERN INTERIOR WHERE THERE WILL BE HIGHER MOISTURE LEVELS
DUE TO THE MOISTURE NOW ADVECTING IN FROM THE SOUTHEAST.

850 MB TEMPERATURES RANGE FROM -10C TO -14C TODAY THEN DROPPING
2-4C ACROSS THE NORTH SLOPE AND NORTHERN INTERIOR FRI WHILE THE
SOUTHERN INTERIOR INCREASES 2C TO 4C FRI. THIS WILL RESULT IN
SURFACE TEMPERATURES STEADY TODAY AND FALLING SLIGHTLY FRI NORTH
OF 66N...AND RISING SLIGHTLY SOUTH OF 66N.

SURFACE...
A 1003 MB LOW IN THE WESTERN CHUKCHI SEA WILL DRIFT NORTH AND
WEAKEN THROUGH TONIGHT. LIGHT SNOW ASSOCIATED WITH THIS OVER NW
ALASKA WILL MOVE NORTH TONIGHT. SW WINDS 25 KT IN THE SOUTHEAST
QUADRANT OF THIS LOW WILL DECREASE TONIGHT AS THE LOW WEAKENS.

STRONG HIGH PRESSURE OVER THE BEAUFORT SEA WILL MOVE NORTHEAST
TONIGHT.

A DEEP LOW IN THE CENTRAL GULF OF ALASKA WILL MOVE SOUTHEAST
THROUGH FRI. AN ASSOCIATED OCCLUDED FRONT IN THE NORTHERN GULF OF
ALASKA WILL MOVE ALONG THE GULF COAST TODAY AND DISSIPATE ALONG AN
ANCHORAGE TO BURWASH LANDING LINE BY 3AM FRI AND THEN DISSIPATING.
THIS FRONT WILL PUSH MID-LEVEL MOISTURE OVER THE EASTERN INTERIOR
THROUGH TONIGHT. THIS WILL BRING A CHANCE OF SNOW TO THE ALASKA
RANGE SE INTERIOR LATE TODAY...AND TO THE REMAINDER OF THE EASTERN
INTERIOR TONIGHT. THERE WILL BE A HIGH PROBABILITY OF SNOW
ASSOCIATED WITH THE SECOND SHORT WAVE MENTIONED ABOVE TONIGHT AND
FRI AS IT MOVES ACROSS THE EASTERN INTERIOR CAUSING VERTICAL
MOTION OF THE MOISTURE THAT ADVECTS IN TONIGHT.

A LOW IN THE FAR WESTERN BERING SEA WILL MOVE EAST AND DEEPEN RAPIDLY
THROUGH TONIGHT. BY 3AM FRI EXPECT A 945 MB LOW IN THE WEST
CENTRAL BERING WITH A FRONT STRETCHING EAST ACROSS THE BERING SEA.
BY 3PM FRI EXPECT A 953 MB LOW IN THE CENTRAL BERING SEA WITH A
FRONT FROM ST MATTHEW ISLAND TO KING SALMON. BY 3AM SAT EXPECT A
959 MB LOW ABOUT 150 NM NORTHWEST OF SAINT PAUL ISLAND WITH A
FRONT FROM ST MATTHEW IS TO NORTON SOUND TO MCGRATH. BY 3PM SAT
EXPECT A 967 MB LOW NEAR NUNIVAK IS WITH A FRONT FROM ST MATTHEW
IS TO NOME TO MCGRATH. EXPECT 2-4 INCHES OF SNOW WITH THIS FRONT
AND LOW. ALSO EXPECT EAST WINDS 40-50KT ALONG THE FRONT OVER THE
NORTHERN BERING SEA THU NIGHT THROUGH FRI NIGHT. THIS COULD CAUSE
BLIZZARD CONDITIONS ZONES 213 AND 214 AS SNOW MOVES IN FRI.

.DISCUSSION...
MODELS INITIALIZE OK ABOVE THE SURFACE AND SHOW SIMILAR
SOLUTIONS OVER NORTHERN ALASKA THROUGH SAT. ALL MODELS ABOUT 7 MB
TOO WEAK ON DEPTH OF LOW IN THE GULF OF ALASKA AT 06Z THU BUT MAIN
IMPACT OF THAT WILL BE SOUTH OF NORTHERN ALASKA.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FOR AKZ213-AKZ214.

HEAVY FREEZING SPRAY WARNING FOR PKZ210.

GALE WARNING FOR PKZ210.

STORM WARNING FOR PKZ210.

BRISK WIND ADVISORY FOR PKZ200-PKZ225.
&&

JB DEC 15