Strong Wind in Alaska, May 31, 2015

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
135 PM AKDT SUN MAY 31 2015

.DISCUSSION...

ALOFT AT 500 MB...THE MODELS ARE IN FAIRLY DECENT AGREEMENT WITH
EXCEPTION OF NAM BEING A LITTLE FAST IN PUSHING THE SHORTWAVE
SOUTHWARD OVER THE EASTERN BROOKS INTO THE INTERIOR COMPARED TO
THE GFS AND ECMWF. IN EITHER CASE...EXPECT THE CLOSED LOW TO
WEAKEN INTO A SHORTWAVE TROUGH BY MONDAY MORNING AS THE EXTENDS
FROM FOR YUKON AND THEN PUSHES FURTHER SOUTH TO CHICKEN BY MONDAY
AFTERNOON. ANOTHER SHORTWAVE TROUGH IN THE ARCTIC NORTH OF BARTER
ISLAND WILL DEVELOP ON MONDAY NIGHT MOVE TOWARD THE EASTERN ARCTIC
COAST AND BROOKS RANGE BY TUESDAY MORNING. THIS TROUGH WILL THEN
DEVELOP A CLOSED LOW OVER THE WESTERN BROOKS RANGE AS IT SHIFTS
WEST BY THURSDAY AS RIDGING BEGINS TO PUSH BACK INTO THE EASTERN
INTERIOR ON THURSDAY.

AT THE SURFACE...WITH THE 1040 MB HIGH PRESSURE OVER THE ARCTIC
AT 76N AND 175 AS IT MOVES SOUTHWARD TOWARDS WRANGLE ISLAND AND
THE 1011 MB LOW PRESSURE OVER PRINCE WILLIAM SOUND WILL BUILD A
NICE PRESSURE GRADIENT AS THE FRONTAL SYSTEM FROM THE ARCTIC
MOVES SOUTHWARD TODAY INTO THE INTERIOR. WINDS AREA EXPECTED TO
PICK UP OVER NIGHT TONIGHT WITH THE STRONGEST AND LINGER INTO
MONDAY BUT WILL WEAKEN THROUGH THE DAY AS THE SYSTEM WEAKENS.
ALTHOUGH THE FRONT WILL BRING COLDER AIR BEHIND IT.

ARCTIC COAST AND BROOKS RANGE...A CONTINUED ACTIVE WEATHER PERIOD
TODAY AND TOMORROW. MAINLY FOR EASTERN PORTIONS OF THE BROOKS AND
ARCTIC COAST WITH WITH MAINLY SNOW SHOWERS WITH UP TO 2 INCHES OF
ACCUMULATIONS. ALTHOUGH MODEL FORECASTS SHOW SLIGHTLY HIGHER...IT
IS DIFFICULT WITH THE OBSERVED TEMPERATURES TO GET SNOW RATIOS
THAT HIGH FROM THE MODELS. EXPECT ACTIVE PERIOD TO CONTINUE AS
ANOTHER SYSTEM WILL BRING ANOTHER ROUND OF SNOW ON TUESDAY NIGHT
INTO MID WEEK. HOWEVER THIS SYSTEM WILL DROP TO THE WEST ACROSS
THE NORTHWEST ALASKA. WITH THE NEXT SHORT WAVE TROUGH...SEVERAL
ADDITIONAL INCHES OF SNOW POSSIBLE AT HIGHER ELEVATIONS IN THE
EASTERN BROOKS RANGE TUESDAY AFTERNOON AND TUESDAY NIGHT...WITH
RAIN OR MIXED RAIN AND SNOW AT LOWER ELEVATIONS.

WEST COAST AND WESTERN INTERIOR...MAIN IMPACTS WILL BE WITH
SCATTERED RAIN SHOWERS AND ISOLATED THUNDERSTORMS FOR AREAS ON
THE YUKON DELTA WITH AREAS SOUTH OF UNALAKLEET AND ANVIK THIS
AFTERNOON AND EVENING. MAINLY RAIN SHOWERS WILL CONTINUE TO TAPER
OFF ON MONDAY FOR THE SAME AREA, WITH NO REAL GOOD LI AND CAPE FOR
THUNDERSTORMS EXCEPT FOR EXTREME SOUTHERN PORTIONS OF YUKON DELTA .
THE RIDGE WILL BEGIN TO BREAK DOWN AND THE WESTERN INTERIOR AND
WEST COAST WILL SEE COOLER TEMPERATURES AND INCREASED SHOWERS
AFTER WEDNESDAY.

CENTRAL AND EASTERN INTERIOR...AS WE HAVE ADVERTISING FOR LAST
SEVERAL DAYS...SUBSTANTIALLY COOLER AIR WILL MOVE INTO THE
INTERIOR TODAY THROUGH TUESDAY. TONIGHT TEMPERATURES WILL BE
TRICKY...EXPECT THE WINDS TO COME UP WHICH WILL HELP KEEP THE
INTERIOR LOW TEMPERATURES GETTING TOO LOW. HOWEVER...COULD SEE
LOW LYING OR SHELTERED AREAS DIP NEAR THAT FROST ADVISORY
CRITERIA WHICH IS BELOW 35 DEGREES FOR TONIGHT. FAIRBANKS AIRPORT
SHOULD REMAIN IN THE LOWER 40S BUT SURROUNDING COLD SPOTS MAY GET
MAY BE IN THE MID TO UPPER 30S. THEN THE COLDEST NIGHT IS
EXPECTED ON MONDAY INTO TUESDAY MORNING WITH FAIRBANKS DROPPING
INTO THE UPPER 30S AND DEFINITELY EXPECT LOW LYING OR SHELTERED
AREAS TO EXPERIENCE FROST CONDITIONS LIKELY. A SPECIAL WEATHER
STATEMENT HAS BEEN SENT DISCUSSING MAIN IMPACTS TO OUTDOOR
SENSITIVE PLANTS OR VEGETATION. ELSEWHERE TEMPERATURES COULD DROP
INTO THE 30S IN THE NORTHERN INTERIOR...AND IN SHELTERED COLD
SPOTS IN THE SOUTHERN INTERIOR. AGAIN THE LOWER TEMPERATURE
READINGS WILL BE MORE WIDESPREAD MONDAY NIGHT WITH THE COLD AIR
MASS IN PLACE AND WINDS DIMINISHING IN THE EARLY EVENING. AS FOR
PRECIPITATION...RAIN WILL BE LIKELY IN PARTS OF THE EASTERN
INTERIOR EAST OF THE MIDDLE TANANA VALLEY THIS EVENING...CHANGING
TO MAINLY SCATTERED SNOW SHOWERS LATER TONIGHT. SCATTERED LOCALLY
NUMEROUS RAIN AND SNOW SHOWERS IN THE SOUTHEAST INTERIOR MONDAY
MORNING BECOMING SCATTERED RAIN SHOWERS MONDAY AFTERNOON.
EXPECTING LESS THAN AN INCH IN THE FORTYMILE COUNTRY ON SUNDAY
NIGHT INTO MONDAY.

EXTENDED FORECAST...FROM MID NEXT WEEK THE UPPER LEVEL SYSTEM THAT
IMPACTED EASTERN BROOKS RANGE WILL SHIFT WEST BUT FROM THAT POINT
THERE ARE DIFFERENCES IN THE ECMWF AND GFS MODELS HANDLE AFTER
THURSDAY AND ALSO THE UPPER LEVEL LOW LOCATED ANYWHERE FROM SOUTH
OF ST LAWRENCE ISLAND TO ST PAUL. FOR NOW TAKE THE ENSEMBLE MEAN
OF THE FORECASTS...WHICH BOTTOM LINE WILL HAVE SLIGHT WARMING
TEMPERATURE TREND ACROSS THE CENTRAL AND EASTERN INTERIOR WITH
POTENTIALLY SOME MIXED CONVECTIVE SHOWERS. FOR THE NORTH SLOPE AND
WESTERN ALASKA EXPECT COOLER TREND WITH WETTER CONDITIONS.

&&

.FIRE WEATHER...
A COLD FRONT OVER THE BROOKS RANGE WILL MOVE CONTINUE TO MOVE SOUTH
OVER THE NORTHERN INTERIOR THIS AFTERNOON ACROSS THE SOUTHERN
INTERIOR TONIGHT. THE FRONT WILL BE OVER THE ALASKA RANGE BY MONDAY.
THERE WILL BE RAIN AND SNOW SHOWERS WITH THE FRONT OVER THE AREA
EAST OF FAIRBANKS THIS AFTERNOON AND TONIGHT. EXPECT STRONG GUSTY
NORTHEAST WINDS WITH THE FRONT. FROM FAIRBANKS WEST THE FRONT WILL
BE DRY AND WILL CAUSE RED FLAG CONDITIONS CONTINUING THIS AFTERNOON
INTO TONIGHT FROM FAIRBANKS WEST. RED FLAG CONDITIONS WILL BE
POSSIBLE AGAIN MONDAY.

&&

.HYDROLOGY...
CANCELLED THE FLOOD ADVISORY FOR ZONE 206 FROM PUMP STATION 3 TO
MILEPOST 286 ON SAG RIVER SINCE WATER RISES ALONG THE KUPARUK
RIVER NEAR DEADHORSE INDICATED THE CREST HAD MOVED DOWNSTREAM ON
THE SAG RIVER. ALASKA DOT REPORTED THAT THE WATER LEVELS HAVE
RISEN 0.5 FEET AND ONE OF THE BENCHMARKS HAD BEEN WASHED AWAY. IT
LOOKS AS THOUGH THE HIGH WATER HAS REACHED THE AREA EARLY THIS
AND WILL CONTINUE TO FALL THROUGH THE DAY TODAY. WILL LIKELY ALLOW
THE FLOOD ADVISORY TO EXPIRE AT 315 PM TODAY.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FOR AKZ222.

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

SMALL CRAFT ADVISORY FOR PKZ200-PKZ210-PKZ215-PKZ220-PKZ230.

GALE WARNING FOR PKZ225.
&&

MAK MAY 15