Small Craft Advisory 1, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
214 PM AKDT MON APR 28 2014

.SYNOPSIS...
ALOFT...
A WEAK RIDGE OVER NORTHERN ALASKA WILL BUILD SLOWLY THROUGH TUE AS
A SHORT WAVE TROUGH NOW ALONG THE NORTHERN BERING SEA MAKES ITS
WAY EAST ACROSS NORTHERN ALASKA TO THE ALCAN BORDER BY 4AM WED.
PRECIPITATION WITH THE TROUGH WILL SPREAD NORTHEAST ACROSS THE
STATE BUT DECREASE TUE AS IT MOVES FURTHER EAST AND THE RIDGE
BUILDS. TEMPERATURES WILL COOL SLIGHTLY TUE WITH THE SHORT WAVE.

STARTING WED A RIDGE BUILDS STRONGLY OVER MAINLAND ALASKA WITH A
570 DM HIGH CENTERED OVER INTERIOR ALASKA BY THU. THIS WILL CAUSE
A RAPID WARMING AND DRYING WED THROUGH FRI. EXPECT ABOVE NORMAL
TEMPERATURES THROUGH WED...AND THEN MUCH WARMER CONDITIONS THU
INTO THE WEEKEND.

SURFACE...
A 1030 MB HIGH NORTH OF THE THE ARCTIC COAST OF ALASKA WILL WEAKEN
THROUGH WED. AN ARCTIC COLD FRONT FROM EAGLE TO ATIGUN PASS TO
POINT HOPE WILL MOVE TO THE ARCTIC COAST TONIGHT AND NORTH OF THE
COAST TUE. STRONG EAST WINDS AND BLOWING SNOW ALONG THE COAST
WILL CONTINUE UNTIL THE FRONT MOVES NORTH OF THE COAST EARLY TUE.

A THERMAL TROUGH FROM MCGRATH TO FAIRBANKS TO EAGLE WILL MOVE TO
FAIRBANKS TO EAGLE BY 4PM TUE AND THEN DISSIPATE. WEAK WINDS WILL
BLOW INTO THIS TROUGH. EXPECT WARMEST TEMPERATURES AND DRIEST
CONDITIONS UNDER THIS TROUGH.

A 987 MB LOW NEAR ANADYR WILL MOVE NORTH AND WEAKEN...AND BY 4AM
WED BY NEAR WRANGEL ISLAND AS A 1004 MB LOW. AN OCCLUDED FRONT
STRETCHING FROM THIS LOW TO ST MATTHEW ISLAND WILL MOVE TO POINT
HOPE TO BETHEL BY 4AM TUE...TO BARROW TO BETTLES TO MCGRATH BY 4PM
TUE...AND TO DEMARCATION POINT TO EAGLE TUE NIGHT. EXPECT 1-2
INCHES OF SNOW WITH THE FRONT ALONG THE WEST COAST...MIXING WITH
RAIN SOUTH OF NOME TO ATIGUN PASS AND FALLING AS RAIN IN THE
INTERIOR SOUTH OF THAT AREA. COULD SEE UP TO 4 INCHES OF SNOW
ALONG HIGHER ELEVATIONS OF THE SOUTH SLOPES OF THE BROOKS RANGE.
AS FRONT MOVES EAST INTO THE EASTERN INTERIOR RAIN WILL DIMINISH
TO SCATTERED SHOWERS SOUTH OF THE BROOKS RANGE.

A STRONG LOW MOVING INTO THE SOUTHERN BERING SEA TUE WILL MOVE TO
THE CENTRAL BERING SEA WED. A WARM FRONT STRETCHING FROM THIS LOW
WILL MOVE NORTH TO THE YUKON DELTA BY 4PM TUE...TO KOTZEBUE TO
ANADYR BY 4AM WED...AND TO BARROW TO ANADYR BY 4PM WED. EXPECT
SNOW CHANGING TO RAIN NEAR THE FRONT WITH RAIN SHOWERS SOUTH OF
THE FRONT. TEMPERATURES WILL RISE RAPIDLY INTO THE UPPER 30S AND
40S ALONG THE FRONT. THIS WILL CAUSE SIGNIFICANT SNOW MELT TO
START ALONG THE WEST COAST.

&&

.DISCUSSION...
MODELS INITIALIZE WELL AND SIMILAR SOLUTIONS THROUGH THU.
EXCEPTION IS PRECIPITATION WHERE THE GFS HAS CONVECTIVE PRECIPITATION
SPREAD OUT OVER A MUCH LARGER AREA THAN OTHER MODELS. PREFER THE
NAM PRECIPITATION.

DIFFERENCES SHOW UP AFTER FRI ON TIMING DIFFERENCES OF A SHORT
WAVE TROUGH MOVING ACROSS NORTHERN AK. WILL USE THE GENERAL
AGREEMENT ON LONG WAVE PATTERN CHANGES TO SHOW WARMING THROUGH FRI
AND COOLING OVER THE WEEKEND TO NEAR NORMAL BY EARLY NEXT WEEK.

&&

.FIRE WEATHER...
EXPECT RH 14-24% SOUTHERN INTERIOR ALONG THERMAL TROUGH THIS
AFTERNOON WITH RED FLAG REMAINING IN EFFECT UNTIL 8PM THIS
EVENING. SLIGHTLY COOLER CONDITIONS EXPECTED TUE WITH RH UP A BIT.
EXPECT SIGNIFICANT WARMING AND DRYING THU AND FRI ACROSS INTERIOR
THAT WILL CONTINUE INTO THE WEEKEND. WILL LIKELY SEE RH BELOW 15%
ACROSS INTERIOR THU INTO THE WEEKEND ALONG WITH VERY WARM
TEMPERATURES.

&&

.HYDROLOGY...
SIGNIFICANT SNOW MELT TO START ALONG THE WEST COAST WED.
FREEZING LEVELS ACROSS INTERIOR 4000-5000 FT THROUGH WED THEN
EXPECTED TO RISE TO 8000 FT BY FRI. THIS WILL CAUSE SIGNIFICANT
MELTING OF HIGH ELEVATION SNOW TO START THU AND FRI START TO FILL
RIVERS UP WITH WATER BY THE WEEKEND.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FOR AKZ222-AKZ223-AKZ225-AKZ226-AKZ227.

WINTER WEATHER ADVISORY FOR AKZ201-AKZ203-AKZ208-AKZ217-AKZ218.

SMALL CRAFT ADVISORY FOR PKZ210.

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

JB APR 14