Blizzard in Alaska, April 10, 2015

NORTHERN ALASKA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FAIRBANKS AK
356 AM AKDT FRI APR 10 2015

.DISCUSSION...

MODELS...FAIRLY GOOD AGREEMENT AMONGST MODEL SOLUTIONS DURING THE
SHORT AND MID RANGE REGARDING THE OVERALL SYNOPTIC PATTERN.
HOWEVER...MODEL SOLUTIONS DISPLAY MINOR DIFFERENCES REGARDING THE
MOVEMENT AND TIMING OF MINOR PERTURBATIONS IN THE WEAK FLOW OVER
ALASKA. AS ALWAYS IN THE EXTENDED...GFS AND ECWMF SOLUTIONS
DISPLAY SIGNIFICANT DIFFERENCES.

ALOFT...A LOW 130 NM EAST OF KODIAK ISLAND WILL DRIFT EAST OVER
THE GULF OF ALASKA AND WEAKEN THROUGH LATE SATURDAY. DESPITE WEAK
FLOW ALOFT...SEVERAL WEAK PERTURBATIONS WILL MOVE OVER PARTS OF
NORTHERN ALASKA. A SHORTWAVE ASSOCIATED WITH THE WEAKENING LOW
WILL MOVE NORTH THIS MORNING AND OVER THE UPPER KUSKOKWIM AND
MIDDLE YUKON VALLEYS. A WEAK VORT MAX...SECOND SHORTWAVE WILL
CONTINUE TO MOVE NORTH ALONG THE ALCAN BORDER...TO OVER THE UPPER
TANANA VALLEY FRIDAY AFTERNOON...AND THEN OVER THE FORTYMILE
COUNTRY SATURDAY MORNING...AND THEN DRIFTS NORTHWEST TOWARDS THE
YUKON FLATS AND THE UPPER KOYUKUK VALLEY BY SUNDAY MORNING.
ANOTHER WEAK UPPER LOW 240 NM SOUTHWEST OF ST LAWRENCE ISLAND THIS
MORNING WILL DRIFT SOUTHEAST AND OVER BRISTOL BAY BY SATURDAY
EVENING.

REGARDING H850 TEMPERATURES...A COOLING TREND WILL BE SEEN OVER
MUCH OF NORTHERN ALASKA AS THE UPPER LEVEL TROUGH SHIFTS EAST OVER
MAINLAND ALASKA. BY SATURDAY...H850 TEMPERATURES OVER THE CENTRAL
AND EASTERN INTERIOR WILL COOL TO NEAR TO SLIGHTLY BELOW NORMAL
VALUES.

SURFACE...A 977 MB LOW OVER THE KENAI PENINSULA THIS MORNING WILL
SLOWLY DRIFT EAST AND WEAKEN...BECOMING A 990 MB LOW STRETCHING
FROM YUKUTAT TO TRAPPER CREEK SUNDAY AFTERNOON. A 984 MB LOW WILL
DEVELOP LATER THIS MORNING SOUTH OF EAGLE AND THEN WILL GRADUALLY
SHIFT TO THE NORTHWEST...AS A 993 MB LOW OVER THE YUKON FLATS
SUNDAY MORNING. AFTER SUNDAY MORNING...POSITIONS OF LOW CENTERS
BECOME A BIT AMBIGUOUS IN THE BROAD TROUGH OVER MAINLAND ALASKA.

NORTH SLOPE...A COOLING TREND IS EXPECTED INTO THE WEEKEND AS
UPPER LEVEL TROUGH SETTLES OVER MAINLAND ALASKA. QUIET WEATHER
WILL PERSIST WITH ISOLATED TO SCATTERED SNOW SHOWERS...CLOUDY
SKIES AND LIGHT WINDS.

WESTERN ALASKA...LEFTOVER PRECIPITATION IN THE FORM OF ISOLATED TO
SCATTERED SNOW SHOWERS OVER THE YUKON DELTA AND LOWER YUKON VALLEY
WILL PERSIST TODAY. THE UPPER LOW SOUTHWEST OF ST LAWRENCE ISLAND
WILL GENERATE ISOLATED TO SCATTERED SNOW SHOWERS TO THE ISLAND
THROUGH LATE THIS EVENING...THEN BRING ANOTHER SHOT OF
PRECIPITATION TO THE YUKON DELTA AND LOWER YUKON VALLEY THIS
WEEKEND AS THE LOW MOVES TOWARDS BRISTOL BAY. THE WEAK SHORTWAVE
THAT IS POISED TO MOVE OVER THE MIDDLE YUKON AND UPPER KUSKOKWIM
VALLEYS TODAY WILL BRING A PERIOD OF ISOLATED TO SCATTERED SNOW
SHOWERS TO THAT AREA. WINDS WILL INCREASE NEAR POINT HOPE THIS
MORNING AND IS EXPECTED TO REACH STRONG WIND HEADLINE
CRITERIA...LAST OBSERVATION FROM POINT HOPE WAS ONLY A FEW KNOTS
FROM THE THRESHOLD. NOT EXPECTING ANY ISSUES REDUCTIONS IN
VISIBILITY BELOW A MILE DUE TO BLOWING SNOW AT THIS TIME. WINDS
SHOULD TAPER OFF AT POINT HOPE SATURDAY.

EASTERN AND CENTRAL INTERIOR...THE MAIN STORY WILL BE THE VORT MAX
THAT IS PROGGED TO MOVE NORTH AND OVER THE INTERIOR THROUGH THE
WEEKEND. LIGHT SNOW WILL SPREAD NORTH TOWARDS THE EASTERN BROOKS
RANGE AND THEN WEST TO OVER THE CENTRAL INTERIOR AND DENALI AREA
BY EARLY SATURDAY MORNING. THE PRECIPITATION TYPE WILL FLUCTUATE
FROM A SNOW/RAIN MIX DURING THE DAYTIME AND TRANSITION TO ALL SNOW
DURING THE OVERNIGHT. NOT EXPECTING SIGNIFICANT SNOWFALL
ACCUMULATIONS...BUT OVER THE WEEKEND WE COULD SEE UPWARDS OF 3 TO
4 INCHES OVER THE FORTYMILE COUNTRY NORTH TO THE BROOKS
RANGE...WITH LESSER AMOUNTS...AN INCH OR MAYBE 2...ELSEWHERE
ACROSS THE INTERIOR. MODELS HINT AT A WARMING TREND AND A RIDGE
REESTABLISHING ITSELF TOWARDS THE END OF THE FORECAST PERIOD.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BRISK WIND ADVISORY FOR PKZ210-PKZ220-PKZ225.
&&

LTH APR 15