Small Craft Advisory 114, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
517 AM AKST THU FEB 5 2015

.ANALYSIS AND UPPER LEVELS...
HIGH PRESSURE DOMINATES THE REGION WITH THE CORE OVER THE NORTHERN
BERING. IT CONTINUES ITS SLOW TRACK TOWARDS NORTHEASTERN RUSSIA
WHICH IS BRINGING NORTHERLY FLOW TO THE MAINLAND. THIS IS ALSO
KEEPING DRY AND STABLE CONDITIONS OVER MUCH OF THE MAINLAND. TO
THE SOUTH OF THE ALEUTIANS A LOW IS BEING HELD UP FROM FURTHER
PROGRESSION TO THE NORTH BY THE RIDGING IN THE BERING AND IS
INSTEAD BEING FORCED WEST KEEPING THE MAJORITY OF THE
PRECIPITATION ALONG THE ISLANDS.

&&

.MODEL DISCUSSION...
THE MODELS ARE IN GOOD AGREEMENT OVERALL WITH ONLY SOME MINOR
DISCREPANCIES. ONE OF WHICH IS WITH A LOW MOVING INTO THE GULF ON
FRIDAY. MOST OF THE MODELS ARE IN AGREEMENT ON THE INTENSITY BUT
THE GEM IS SHOWING IT FAIRLY DEEPER THAN THE OTHER MODELS. THE
OTHER ISSUE IS WITH A LOW SOUTH OF THE ALEUTIANS THAT IS TRACKING
EAST FRIDAY NIGHT INTO SATURDAY. HERE THE BIGGEST ISSUE IS
LOCATION WITH THE GFS BEING THE FASTEST AND THE GEM TRAILING
BEHIND.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
WITH THE HIGH OUT WEST OVER THE BERING NORTHERLY FLOW IS EXPECTED
TO CONTINUE THROUGHOUT THE SOUTHCENTRAL FOR THE NEXT COUPLE OF
DAYS. WINDS WILL ALSO INTENSIFY AS WE MOVE INTO FRIDAY DUE TO
SEVERAL DIFFERENT FEATURES OCCURRING IN SERIES. OVERNIGHT TONIGHT
UPPER LEVEL FLOW WILL STRENGTHEN AS A LOW BUILDS IN OVER THE
NORTHEASTERN GULF TIGHTENING THE GRADIENT. THEN ON FRIDAY
AFTERNOON A TROUGH WILL PUSH DOWN FROM THE NORTH FOLLOWED BY COLD
AIR ADVECTION ALL AIDING IN STRONGER WINDS. THIS NORTHERLY FLOW
WILL BE DRY KEEPING THE SKIES CLEAR BUT WITH THE TEMPERATURES
DROPPING AND WINDS INCREASING WIND CHILLS WILL BE A CONCERN FOR
MUCH OF THE SOUTHCENTRAL WITH THE COLDEST CONDITIONS STRETCHING
FROM THE COPPER RIVER BASIN THROUGH VALDEZ.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
DRY CONDITIONS PERSIST INTO THE BEGINNING OF THE WEEKEND ACROSS
THE SOUTHWESTERN MAINLAND. NORTHERLY WINDS INCREASE FRIDAY NIGHT
AS THE PRESSURE GRADIENT TIGHTENS IN RESPONSE TO A DENSE COLD AIR
MASS ADVECTING FROM THE CENTRAL INTERIOR. WIND CHILLS ACROSS THE
SOUTHWEST THROUGH FRIDAY NIGHT WILL RANGE BETWEEN 10 BELOW AND 35
BELOW WITH THE COLDEST VALUES EXPECTED ACROSS THE KUSKOKWIM
VALLEY.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE SURFACE LOW SOUTH OF THE CENTRAL ALEUTIANS WILL MOVE SLOWLY
WEST TODAY BRINGING GUSTY WINDS AND PRECIPITATION TO THE
ALEUTIANS AND SOUTHERN BERING. THE STRONGEST WINDS OCCUR WITH THIS
SYSTEM DURING THE MORNING HOURS TODAY ACROSS THE EASTERN
ALEUTIANS. PRECIPITATION WILL BE A MIX OF RAIN AND SNOW ACROSS THE
BERING/ALEUTIANS AS A WARMER COLUMN OF AIR WRAPS NORTH OF THE LOW
CENTER. THIS LOW WEAKENS TONIGHT AND HIGH PRESSURE BUILDS INTO THE
NORTHERN BERING. GUSTY GRADIENT WINDS CONTINUE INTO SATURDAY AS A
COLDER AIR MASS ADVECTS WESTWARD FROM THE BERING STRAIT AND THE
MAINLAND.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...
STRONG OUTFLOW WINDS AND VERY COLD WIND CHILL VALUES WILL REMAIN
THE PRIMARY FORECAST CONCERNS INTO THE WEEKEND AS DRY OFFSHORE
FLOW CONTINUES TO DOMINATE THE SOUTHERN MAINLAND...WITH LOW
PRESSURE OVER THE GULF HELPING TO MAINTAIN A TIGHT PRESSURE
GRADIENT AND ARCTIC AIR FILTERING INTO THE REGION IN NORTHERLY
FLOW. WINDS WILL BEGIN TO GRADUALLY DIMINISH BY SUNDAY INTO THE
EARLY PART OF NEXT WEEK AS THE GULF LOW WEAKENS AND UPPER LEVEL
SUPPORT BEGINS TO WANE. MODELS ARE THEN HINTING AT A PATTERN
CHANGE DURING THE MIDDLE OF NEXT WEEK AS THE BERING HIGH
RETROGRADES INTO EASTERN RUSSIA AND A BROAD LONGWAVE TROUGH
BECOMES ESTABLISHED FROM THE CANADIAN ARCTIC SOUTHWESTWARD INTO
THE NORTH PACIFIC. THIS WOULD YIELD SOUTHERLY FLOW OVER THE
MAINLAND WITH REBOUNDING TEMPERATURES AND AN INCREASED CHANCE OF
PRECIPITATION...PARTICULARLY ALONG THE GULF COAST.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND CHILL ADVISORY 131 141
MARINE...GALE WARNING 121 126 127 128 130 131 132 139 140 141
					  170 173 175 177 179 180 185
 		 HEAVY FRZ SPRAY 121 126 127 128 129 139 140 141 185
FIRE WEATHER...NONE

&&

SYNOPSIS AND MODEL DISCUSSION...DK
SOUTHCENTRAL ALASKA...DK
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...KH
LONG TERM...CB