Winter Weather Advisory 252, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
423 AM AKDT MON APR 6 2015

.SYNOPSIS...
ALOFT...
LONG WAVE RIDGE OVER THE NE PACIFIC AND MAINLAND ALASKA WILL MOVE
TO THE ALCAN BORDER BY EARLY TUE AND MOVE SLOWLY EAST. THE LONG
WAVE TROUGH OVER THE NW PACIFIC AND BERING SEA WILL PROGRESS
SLOWLY EAST TO A POSITION OVER MAINLAND ALASKA BY FRI. THIS MEANS
THAT THE SOUTHERLY FLOW OF WARM MOIST AIR NOW DEVELOPING OVER
NORTHERN ALASKA WILL BRING TEMPERATURES WELL ABOVE NORMAL THROUGH
MID- WEEK...THEN COOL TO BELOW NORMAL BY THE WEEKEND.

WEAK SOUTHERLY CHINOOK FLOW TODAY OVER THE ALASKA RANGE WILL
INCREASE TONIGHT AND REACH A PEAK TUE WITH SOUTH FLOW UP TO 70KT
AT 700 MB THEN DECREASE TUE NIGHT. WILL ISSUE HIGH WIND WARNING
FOR ZONE 225 BEGINNING 6PM TONIGHT AND ZONE 226 10PM TONIGHT.
WILL ISSUE WIND ADV ZONE 223 STARTING 10PM MON.

SURFACE...
STRONG HIGH PRESSURE NORTH OF THE ARCTIC COAST WILL WEAKEN SLOWLY
THROUGH TUE. THIS COMBINED WITH THE LOWS MENTIONED IN THE
FOLLOWING PARAGRAPHS IS CAUSING E WINDS 20-30 KT ALONG THE ARCTIC
COAST. THESE WINDS WILL INCREASE TO 25-35 KT TUE ALONG THE ARCTIC
COAST AS THE FRONTAL WAVE MOVES NORTH.

A 977 MB LOW 100 NM NORTH OF ST MATTHEW ISLAND WILL MOVE TO 100 NM
EAST OF ST MATTHEW ISLAND BY 4PM MON...TO THE KUSKOKWIM DELTA AS A
982 MB LOW BY 4AM TUE...AND DISSIPATING NEAR BETHEL TUE PM. AN
OCCLUDED FRONT STRETCHING FROM THE LOW TO NOME TO KING SALMON WILL
MOVE TO THE BERING STRAIT TO GALENA TO A FRONTAL WAVE NEAR KING
SALMON BY 4PM MON...TO THE BERING STRAIT TO KOTZEBUE TO A FRONTAL
WAVE NEAR ILIAMNA BY 4AM TUE. EXPECT 2-4 INCHES OF SNOW AHEAD OF
THE FRONT CHANGING TO RAIN AND SNOW ALONG AND SOUTH OF THE FRONT
WITH AN ADDITIONAL 1-2 INCHES OF SNOW. ALSO EXPECT NE WINDS
20-30KT AND BLOWING SNOW NORTH OF THE FRONT WITH GUSTS 35KT ZONE
213.

THE FRONTAL WAVE WILL MOVE TO NEAR MCGRATH BY 4PM TUE AS A 981 MB
LOW AND TO AMBLER BY 4AM WED AS A 987 MB LOW...AND TO HOWARD PASS
BY 4PM WED AS A 990 MB LOW. A WARM FRONT FROM THE LOW TO ARCTIC
VILLAGE AT 4PM TUE...WILL MOVE TO AMBLER TO BARTER ISLAND BY 4AM
WED AND TO HOWARD PASS TO BARROW NE BY 4PM WED. EXPECT FREEZING
LEVELS 3000-5000 FT FROM THIS LOW EAST ALONG THE WARM FRONT.
EXPECT MIXED RAIN AND SNOW AHEAD OF THE LOW IN THE WESTERN
INTERIOR AND WEST COAST. THE RAIN AND SNOW WILL CHANGE TO RAIN
ALONG AND EAST OF THE LOW. EXPECT 2-4 INCHES OF SNOW IN THE
WESTERN INTERIOR TUE- WED. THE EASTERN INTERIOR WILL HAVE A
STRONG CHINOOK AND LITTLE PRECIPITATION.

&&

.DISCUSSION...
MODELS INITIALIZE OK AT 500 MB. SIMILAR SOLUTIONS THROUGH 4AM TUE
THEN THE GFS HAS A STRONGER SHORT WAVE MOVING NORTH OVER MAINLAND
ALASKA. AT THE SURFACE MODELS SIMILAR THROUGH 4PM MON...THEN NAM
TAKES THE FRONTAL WAVE NW FASTER AND MORE STRONGLY THAN THE GFS.
PREFER THE GFS SINCE THE MAIN SHORT WAVE SUPPORTING THE SURFACE
WAVE/LOW TRACKS NORTH MORE IN LINE WITH THE GFS SURFACE LOCATION.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FOR AKZ223.

BLIZZARD WARNING FOR AKZ213.

HIGH WIND WARNING FOR AKZ225-AKZ226.

GALE WARNING FOR PKZ210.

BRISK WIND ADVISORY FOR PKZ200-PKZ210-PKZ215-PKZ220-PKZ225-
PKZ230-PKZ235-PKZ240-PKZ245.
&&

JB APR 15