Strong Wind in Alaska, April 19, 2015

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
616 AM AKDT SUN APR 19 2015

.DISCUSSION...
MODEL SOLUTIONS REMAIN SOLID WITH GOOD CONTINUITY BETWEEN MODEL
FAMILIES AND RUN TO RUN CONTINUITY ON FEATURE TRACK...POSITION AND
STRENGTH THROUGH 48 HOURS AND THEN EXHIBIT EXPECTED AMOUNTS OF
SPREAD THROUGH THE MID TERM AND LONG TERM. MODELS AS WOULD BE
EXPECTED ARE HAVING A DIFFICULT TIME RESOLVING SHORT WAVES MOVING
NORTH ALONG THE BACK OF RIDGE OVER EASTERN ALASKA EARLY THIS NEXT WEEK
AND ROTATING AROUND THE LONG WAVE TROUGH CENTERED OVER WESTERN
AND CENTRAL ALASKA BY THE MIDDLE AND END OF NEXT WEEK.

ALOFT AT 500 HPA... A COMPLEX 506 DAM LOW CENTER WITH CENTERS
NEAR ST MATTHEW ISLAND AND NUNIVAK ISLAND WILL CONSOLIDATE OVER
THE CENTRAL BEING SEA AS A SHORT WAVE OVER SOUTH CENTRAL ALASKA
MOVES NORTH OVER THE ALASKA RANGE TODAY. THE CONSOLIDATED UPPER
LEVEL LOW WILL DRIFT SOUTH AND EAST TO BE LOCATED JUST SOUTH OF
NUNIVAK ISLAND MONDAY MORNING AND THEN DRIFT NORTHEAST OVER THE
LOWER YK DELTA MONDAY NIGHT. THE LOW WILL DRIFT NORTHWEST TO BE
LOCATED NEAR ST LAWRENCE ISLAND TUESDAY MORNING. THE UPPER LEVEL
RIDGE WILL DRIFT EAST AND WILL BE CENTERED OVER THE YUKON
TERRITORY MONDAY MORNING AND WILL CONTINUE TO DRIFT EAST INTO THE
NORTHWEST TERRITORIES TUESDAY MORNING.

ON THE SURFACE A DOUBLE BARREL LOW PRESSURE WITH THE PRIMARY LOW
OVER SAND POINT AS A 982 MB LOW AND A SECONDARY 983 MB LOW OVER
ST LAWRENCE ISLAND WILL CONTINUE TO DRIFT TO THE NORTH WITH THE
LOW OVER ST LAWRENCE ISLAND MOVING NORTHWEST INTO THE GULF OF
ANADYR AND THE SOUTHERN LOW DRIFTING NORTH INTO THE LOWER YK DELTA
TONIGHT AND OVER THE BERING STRAIT MONDAY MORNING.

WEST COAST AND WESTERN INTERIOR...MESSY MIX OF WEATHER IN THE WEST
TODAY WITH SNOW...WIND...RAIN SHOWERS...SNOW SHOWERS AND EVEN
SOME ISOLATED THUNDERSTORMS POSSIBLE THIS AFTERNOON OVER SOUTHERN
AREAS WEST OF MCGRATH. WARM AND MOIST AIRMASS MOVING TO THE NORTH
AND NORTHWEST OVER THE WESTERN INTERIOR WITH MANY LOWER ELEVATIONS
IN ALREADY THE UPPER 30 AND MID 40S AND HIGHER TERRAIN IN THE
UPPER 20 AND 30S. 850 TEMPERATURES STILL IN THE 4 BELOW RANGE AND
NEAR SURFACE DEW POINT DEPRESSIONS IN THE 4 DEGREE RANGE SO FROZEN
PRECIP LIKELY TO MIX IN WITH SHOWERS TODAY DESPITE SURFACE
TEMPERATURES IN THE 40S AND 50S THIS AFTERNOON. ICE PELLETS
POSSIBLE IN STRONGER SHOWERS AND THUNDERSTORMS TODAY AND THIS
EVENING WITH LIFTED INDEX IN THE MINUS 1 TO MINUS 2 RANGE AND CAPE
VALUES IN THE 200 TO 400 RANGE.

CENTRAL AND EASTERN INTERIOR WILL AGAIN BE WARM AND DRY WITH
ONGOING CHINOOK EVENT. WINDS IN AND NEAR THE ALASKA RANGE PEAKED
AT MAXIMUM ADVISORY LEVELS LAST NIGHT BUT DIMINISHED SOME EARLY
THIS MORNING...HOWEVER WITH AN EVEN STRONGER SHORT WAVE MOVING
NORTH OVER THE ALASKA RANGE TODAY AND COMBINED WITH 60 KTS JET MAX
AT MOUNTAIN TOP LEVEL AND FAVORABLE MOUNTAIN WAVE
ENVIRONMENT...UPGRADED WIND ADVISORIES IN ZONES 225 AND 226 TO
WARNINGS. ZONES 223 AND 227 WILL AGAIN PUSH MAXIMUM ADVISORY
LEVELS TODAY. TEMPERATURES ARE EXPECTED TO REACH THE UPPER 50S
TODAY IN FAIRBANKS WITH. GUSTY WINDS WILL BE FOUND OVER MUCH OF
THE INTERIOR TODAY ESPECIALLY OVER HIGHER TERRAIN.

ON THE NORTH SLOPE...APPROACHING LOW FROM SOUTH OF THE BERING
STRAIT WILL BRING SCATTERED SNOW SHOWERS OVER THE WESTERN NORTH
SLOPE. EAST WINDS WILL INCREASE TODAY AS THE GRADIENT BETWEEN
APPROACHING LOW AND A HIGH PRESSURE RIDGE TO THE NORTH BUILDS.
WINTER WEATHER ADVISORIES ISSUED FOR ZONES 201...203 AND 204 FOR
BLOWING SNOW REDUCING VISIBILITY TO LESS THAN ONE HALF MILE AT
TIMES THROUGH THIS EVENING. VISIBILITIES WILL IMPROVE TONIGHT AS
WINDS DECREASE.

&&

.FIRE WEATHER...
MIN RH VALUES WILL AGAIN DROP INTO THE 20S IN THE CHINOOK ZONES
NEAR THE ALASKA RANGE THIS AFTERNOON...COMBINED WITH WARNING AND
ADVISORY LEVEL WINDS WILL PRODUCE METEOROLOGICAL RED FLAG
CONDITIONS TODAY HOWEVER FUELS IN SNOW FREE ZONE REMAIN TOO MOIST.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FOR AKZ223-AKZ227.

HIGH WIND WARNING FOR AKZ225-AKZ226.

WINTER WEATHER ADVISORY FOR AKZ201-AKZ203-AKZ204.

GALE WARNING FOR PKZ210-PKZ225-PKZ230-PKZ235-PKZ240-PKZ245.

BRISK WIND ADVISORY FOR PKZ200-PKZ215-PKZ220.
&&

CCC APR 15