Winter Weather in Alaska, June 1, 2015

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
507 AM AKDT MON JUN 1 2015

.DISCUSSION...

UPPER AIR...GOES IR LOOP SHOWS THE UPPER LOW CENTER ABOUT 100
MILES NORTH OF FAIRBANKS AT 12 AM THIS MORNING. CURRENT MODEL
RUNS OPEN THE UPPER LOW INTO A TROUGH AND SWING IT SOUTHEASTWARD
TO THE ALCAN BORDER BY LATE THIS AFTERNOON. THE NEXT SHORT WAVE
TROUGH...NOW OVER THE NORTH POLE...WILL MOVE SOUTHWARD TO THE
EASTERN ARCTIC COAST BY EARLY TUESDAY MORNING. CURRENT MODELS
AGREE WELL ON THIS FORECAST POSITION. BY EARLY WEDNESDAY
MORNING...AN UPPER LEVEL TROUGH WILL DIG SOUTHWESTWARD FROM THE
EASTERN ARCTIC COAST TO THE LOWER YUKON VALLEY. A SECOND SHORT
WAVE TROUGH COMING OUT OF THE HIGH ARCTIC WILL MOVE TO ABOUT 50
MILES EAST OF BARROW BY WED EVENING...PULLING THE NORTHERN PART OF
THE UPPER LEVEL TROUGH WESTWARD AND BRINGING ADDITIONAL SURGES OF
COLDER AIR ALOFT TO THE ARCTIC SLOPE AND BROOKS RANGE. CURRENT
GFS/NAM12/ECMWF AGREE WELL ON THIS TREND. COOL AIR ALOFT OVER THE
NORTHERN AND EASTERN INTERIOR WILL PERSIST THROUGH WEDNESDAY
NIGHT. A MODERATING TREND WILL BEGIN LATE IN THE WEEK...WITH
EASTERN AND SOUTHEASTERN INTERIOR TEMPERATURES RECOVERING TO NEAR
NORMAL VALUES BY THE WEEKEND. FARTHER TO THE NORTH AND WEST...A
STRONG UPPER LEVEL HIGH CENTERED 500 MILES NORTH OF THE CHUKOTSK
PENINSULA WILL MIGRATE SOUTHWESTWARD TO NEAR WRANGEL ISLAND BY
TUESDAY AFTERNOON AND TO 400 MILES WEST OF THE BERING STRAIT BY
WEDNESDAY AFTERNOON. HIGH PRESSURE RIDGING OVER THE NORTHERN
BERING SEA AND SOUTHWEST ALASKA WILL BREAK DOWN BY TUESDAY
AFTERNOON.

SURFACE...
A 1038 MB HIGH CENTERED 350 MILES NORTHWEST OF BARROW WILL WEAKEN
TO A 1025 MB HIGH CENTERED NEAR WRANGEL ISLAND BY WEDNESDAY
MORNING. A STRONG SEA LEVEL PRESSURE GRADIENT ACROSS THE BROOKS
RANGE AND THE NORTHERN TWO THIRDS OF THE INTERIOR WILL WEAKEN
VERY GRADUALLY THROUGH WEDNESDAY. BREEZY CONDITIONS WILL CONTINUE
OVER THE BROOKS RANGE AND THE NORTHERN TWO THIRDS OF THE INTERIOR
THROUGH TUESDAY. WINDY CONDITIONS ARE EXPECTED TO CONTINUE INTO
TUESDAY NIGHT OVER THE BROOKS RANGE AND THE NORTHERN THIRD OF THE
INTERIOR...AND POSSIBLY IN THE MIDDLE TANANA VALLEY AND CENTRAL
INTERIOR ZONES. A THERMAL LOW PRESSURE TROUGH SOUTH OF THE ALASKA
RANGE WILL GRADUALLY WORK ITS WAY NORTHWARD TO THE ALASKA RANGE BY
TUESDAY EVENING...THEN REMAIN NEARLY STATIONARY THROUGH WEDNESDAY
EVENING. BELOW NORMAL TEMPERATURES WILL CONTINUE OVER THE INTERIOR
THROUGH MOST OF THE WEEK...RECOVERING TO NEAR NORMAL IN THE
EASTERN AND SOUTHEASTERN INTERIOR BY THE WEEKEND.

OVER THE EASTERN ARCTIC COAST AND EASTERN ARCTIC SLOPE...ABOUT AN
INCH OF SNOW EXPECTED TUESDAY. SCATTERED RAIN AND SNOW SHOWERS
ARE EXPECTED OVER THE SOUTHEASTERN BROOKS RANGE TUESDAY AND
TUESDAY NIGHT.

THE SOUTHWARD MOVING UPPER LOW WILL PRODUCE SHOWERS OVER PARTS OF
THE EASTERN INTERIOR THROUGH THIS EVENING. SHOWERS WILL BE
NUMEROUS IN THE UPPER TANANA VALLEY AND FORTYMILE COUNTRY...AND
SCATTERED ELSEWHERE. LOW TEMPERATURES IN THE 30S ARE EXPECTED OVER
THE NORTHERN INTERIOR AND FORTYMILE COUNTRY TONIGHT. IN THE
SOUTHERN INTERIOR AREAS INCLUDING THE MIDDLE TANANA VALLEY...NORTH
TO NORTHEAST WINDS SHOULD KEEP TEMPERATURES UP IN MOST AREAS...BUT
LOWS IN THE MID TO UPPER 30S COULD BE POSSIBLE IN LOW LYING
SHELTERED AREAS WITH LITTLE WIND. BREEZY CONDITIONS WILL CONTINUE
IN MOST AREAS OF THE INTERIOR THROUGH TUESDAY. A RETURN FLOW OF
MOISTURE IS EXPECTED TO BEGIN IN THE SOUTHEAST INTERIOR TUESDAY IN
A SOUTHWESTERLY UPPER WIND FLOW. THIS SHOULD BRING AN INCREASE IN
CLOUDINESS WITH SHOWERS POSSIBLE OVER THE ALASKA RANGE. CLOUD
COVER AND SHOWER ACTIVITY IS EXPECTED SPREAD NORTHWARD AND
EASTWARD ACROSS THE SOUTHERN AND EASTERN INTERIOR TUESDAY NIGHT
AND WEDNESDAY.

&&

.FIRE WEATHER...
VERY DRY AIR WILL PERSIST OVER THE MUCH OF THE INTERIOR THROUGH
WEDNESDAY...WITH SURFACE DEW POINTS AS LOW AS THE TEENS AND 20S
IN MANY AREAS. MINIMUM RH VALUES ARE EXPECTED TO BE LESS THAN 30
PERCENT OVER MOST AREAS OF THE INTERIOR...AND COULD BE AS LOW AS
20 PERCENT IN THE DRIEST AREAS. WIND GUSTS TO 25 MPH OR MORE
WILL OCCUR OVER MANY AREAS OF THE INTERIOR AND IN BROOKS RANGE
PASSES THROUGH THIS EVENING. AFTERNOON AND EVENING WIND GUSTS TO
25 MPH WILL BE POSSIBLE TUESDAY AFTERNOON AND EVENING IN BROOKS
RANGE PASSES AND IN THE NORTHERN THIRD OF THE INTERIOR. RED FLAG
CONDITIONS WILL BE LIKELY IN MANY PARTS OF THE INTERIOR THIS
AFTERNOON AND EVENING. ISOLATED THUNDERSTORMS EXPECTED THIS
AFTERNOON AND EVENING OVER THE YUKON DELTA ZONE. ISOLATED
THUNDERSTORMS POSSIBLE WEDNESDAY AFTERNOON AND EVENING OVER PARTS
OF THE INTERIOR SOUTHEAST OF THE MIDDLE TANANA VALLEY.

&&

.HYDROLOGY...
THE FLOOD ADVISORY FOR THE SAG RIVER FROM PUMP STATION TO
DEADHORSE WAS CANCELLED ON SUNDAY. RIVER LEVELS ON THE SAG RIVER
AT PUMP STATION 3 AND THE COLVILLE RIVER AT UMIAT ARE CONTINUING
TO FALL. THE KUPARUK RIVER NEAR DEADHORSE APPEARS TO HAVE CRESTED
SUNDAY AND IS NOW STARTING A VERY SLOW FALL. SOUTHERN AND EASTERN
INTERIOR RIVERS AND STREAMS CONTINUE TO BE AT VERY LOW STAGES.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

RED FLAG WARNING FOR AKZ208-AKZ216-AKZ217-AKZ218-AKZ219-AKZ221-
AKZ222-AKZ223-AKZ227.

SMALL CRAFT ADVISORY FOR PKZ200-PKZ210-PKZ220-PKZ230.

BRISK WIND ADVISORY FOR PKZ225.

&&

RF MAY 15

&&

RF JUN 15