Gale Warning 50, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FAIRBANKS AK
526 AM AKDT WED MAY 20 2015

UPDATED MARINE ADVISORIES

.DISCUSSION...

UPPER LEVEL...HIGHLY AMPLITUDE PATTERN WILL PERSIST INTO THE MID
TERM FORECAST PERIOD. LONG WAVE HIGH PRESSURE OVER THE YUKON
TERRITORY OF CANADA WITH RIDGING INTO INTERIOR ALASKA COMBINED
WITH LONG WAVE LOW PRESSURE OVER THE SOUTHERN BERING SEA WILL
PRODUCE STRONG SOUTHERLY FLOW ALOFT OVER MUCH OF WESTERN MAINLAND
ALASKA. A SHORT WAVE WILL MOVING EAST OVER NORTHWEST ALASKA
THURSDAY THROUGH FRIDAY WILL CUTOFF MUCH OF THE LONG SOUTHERLY
FETCH THURSDAY NIGHT THROUGH FRIDAY NIGHT. RETURN FLOW WILL OCCUR
DURING THE WEEKEND AS THE LONG WAVE PATTERN REBOUNDS FOLLOWING THE
SHORT WAVES DEPARTURE.

SURFACE...COLD FRONT EXTENDING FROM EASTERN RUSSIA TO THE BERING
STRAIT...NOME...AND SAINT MARY'S WEDNESDAY AFTERNOON WILL MOVE
EAST. THE FRONT WILL BE WEAKENING ALONG A LINE FROM BARROW SOUTH
OVER THE CENTRAL INTERIOR THURSDAY AFTERNOON. ANOTHER COLD FRONT
WILL FOLLOW A SIMILAR PATH THURSDAY THROUGH FRIDAY. THAT COLD
FRONT WILL EXTEND FROM EAST OF BARROW AND SOUTH OVER GALENA AND
ANVIK FRIDAY MORNING. STRONG HIGH PRESSURE OVER THE EASTERN
INTERIOR WILL PREVENT THE FRONT FROM MAKING MUCH FURTHER PROGRESS
EASTWARD. A THERMAL TROUGH FROM THE NEAR BETTLES TO EAGLE
WEDNESDAY AFTERNOON WILL SHIFT TO A FORT YUKON TO EAGLE LINE
THURSDAY AFTERNOON. THE THERMAL TROUGH WILL REFORM FROM THE
CENTRAL INTERIOR TO THE MIDDLE TANANA VALLEY AND EAST TO CANADA
SATURDAY AFTERNOON.

NORTH SLOPE...FRONT MOVING NORTH FROM THE SOUTH CHUKCHI SEA WILL
BRING RAIN SHOWERS TO THE NORTHWEST ARCTIC COAST TONIGHT AND EAST
OF BARROW THURSDAY. COLD FRONT WILL MOVE EAST OF BARROW BY
THURSDAY MORNING. HIGH PRESSURE BUILDING NORTH OF PRUDHOE BAY ON
FRIDAY WILL DISSIPATE THE FRONT. EAST WINDS WILL INCREASE SATURDAY
AS PRESSURE GRADIENT TIGHTENS BETWEEN THE ARCTIC HIGH AND LOW
OVER THE NORTHEASTERN BERING.

WEST COAST...COLD FRONT MOVING NORTH AND EAST OVER THE AREA WILL
PRODUCE RAIN WITH AMOUNTS UP TO ONE QUARTER INCH TODAY THROUGH
TONIGHT. PRECIPITATION TYPE WILL CHANGE TO SNOW FOR SAINT LAWRENCE
ISLAND TONIGHT...BUT AMOUNTS WILL BE LIGHT. HIGH PRESSURE BUILDING
THURSDAY NIGHT AND FRIDAY WILL BRING DRIER CONDITIONS. A RETURN TO
RAIN AND SOUTHEAST WINDS IS FORECAST FOR FRIDAY NIGHT AND SATURDAY
AS ANOTHER LOW MOVES EAST FROM THE WESTERN BERING SEA.

INTERIOR...NEAR RECORD HIGH TEMPERATURES AND DRY CONDITIONS WILL
PERSIST FOR THE EASTERN INTERIOR. THE CENTRAL TO WESTERN INTERIOR
WILL HAVE MORE CLOUDS AND SOME ISOLATED RAIN SHOWERS THURSDAY AS
A COLD FRONT MOVES OVER THAT AREA. ON FRIDAY...AFTER THE FRONT
DISSIPATES...RH'S WILL FALL IN THE CENTRAL TO WESTERN INTERIOR.

&&

.FIRE WEATHER...MODELS FORECAST A CONTINUATION OF VERY DRY
CONDITIONS FROM THE CENTRAL INTERIOR EAST OVER THE REST OF THE
INTERIOR THROUGH AT LEAST THE WEEKEND. ANY LIGHTNING STRIKES WHICH
OCCUR IN NORTHERN ALASKA WILL BE LIMITED TO NEAR THE CANADIAN
BORDER TODAY AND THURSDAY IN THE AFTERNOON AND EVENING.

&&

.HYDROLOGY...FLOOD WARNING CONTINUES UNTIL FRIDAY AT 1115PM FOR
PORCUPINE RIVER AT FORT YUKON. THE REST OF THE PORCUPINE RIVER
FROM THE CANADIAN BORDER TO JUST UPRIVER OF FORT YUKON CONTINUES
WITH A FLOOD WATCH THROUGH WEDNESDAY EVENING. FLOOD WATCH REMAINS
IN EFFECT THROUGH SATURDAY AFTERNOON IN ZONE 203 FOR THE SAG...
COLVILLE...AND KUPARUK RIVERS. DALTON HIGHWAY FLOOD ADVISORY IN
EFFECT UNTIL WEDNESDAY AT 1000PM FROM MILEPOST 399 TO 405.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FOR AKZ220-AKZ222-AKZ223-AKZ224-AKZ225-AKZ226-
AKZ227.

FLOOD WATCH FOR AKZ203-AKZ220.

SMALL CRAFT ADVISORY FOR PKZ200-PKZ210-PKZ215-PKZ220.

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

DA MAY 15