Small Craft Advisory 296, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
130 PM AKDT THU APR 4 2013

.MODEL DISCUSSION...MOSTLY GFS USED FOR THE WESTERN DOMAIN THROUGH
THE WEEKEND AND A BLEND OF NAM/GFS FOR THE EASTERN.

.ANALYSIS AND UPPER LEVELS...COLD UPPER LOW ACROSS THE CANADIAN HIGH
ARCTIC CONTINUES TO EXPAND SOUTHWESTWARD OVER EASTERN HALF OF ALASKA.
INCREASED UPPER SUPPORT HAS HELPED PICK UP THE CHANNELED NORTHERLIES
IN MOST OF THE USUALLY WINDIER AREAS OF SOUTH CENTRAL ALASKA. DON'T
EXPECT THESE WINDS TO INCREASE TOO MUCH MORE SINCE WITH TIME THE
UPPER LEVEL FLOW BECOMES WESTERLY LATE TONIGHT AND FRI MORNING. BY
FRI AFTERNOON ALL OF MAINLAND ALASKA WILL BE DOMINATED BY UPPER LOW
PRESSURE CENTERED NEAR ARCTIC VILLAGE. AN UPPER RIDGE WILL REMAIN
OVER MOST OF THE BERING BUT WEAKEN BY FRI EVENING. VERY COLD ARCTIC
AIR WILL BUILD UP ALONG THE CENTRAL AND EASTERN ALASKA RANGE AND
SLIDE SOUTHWEST OVER THE LOWER YUKON AND KUSKOKWIM RIVER VALLEYS
LATER IN THE DAY FRI, THEN PUSH ACROSS THE KUSKOKWIM DELTA AND
NORTHERN BRISTOL BAY AREAS SATURDAY.

GALES FORCE SOUTHEASTERLIES BLOWING ACROSS THE ALASKA PENINSULA, WITH
GUSTS OVER 50 MPH AT COLD BAY, WILL BEGIN TO DIMINISH LATER THIS
AFTERNOON AND TONIGHT AS THE FRONTAL BOUNDARY WEAKENS, AND THE
ORIENTATION OF THE GRADIENT BECOMES MORE EAST/WEST. A
QUASI-STATIONARY SURFACE LOW SETS UP NEAR 50N 158W THURSDAY NIGHT.
EAST OR NORTHEAST WINDS WILL BLOW ACROSS ALL OF THE FORECAST AREA FOR
THE NEXT COUPLE OF DAYS.

UPPER LOW CENTER MOVES TO THE LOWER YUKON VALLEY SAT AFTERNOON THEN
PULLS EAST OVER THE KUSKOKWIM VALLEY BY SUN MORNING. THIS PUTS THE
FORECAST AREA EAST OF THE ALASKA RANGE UNDER INCREASING SOUTHWESTERLY
FLOW WHICH DEFINITELY MEANS ANOTHER ROUND OF SIGNIFICANT SNOW FOR
THAT AREA BEGINNING AS EARLY AS FRI EVENING. AS IS USUALLY THE CASE,
TIMING THE ONSET OF SNOW FOR THE AREA FROM ANCHOR POINT NORTH TO
PALMER AND THE SOUTHERN SUSITNA VALLEY WILL BE AS DIFFICULT AS USUAL.

SUNDAY LOOKS VERY WET ALONG THE NORTH GULF COAST AND PRINCE WILLIAM
SOUND WITH MODERATE TO HEAVY RAIN/SNOW WITH SNOW EXTENDING WEST
ACROSS NORTHERN COOK INLET, AND LITER AMOUNTS IN THE SUSITNA AND
KUSKOKWIM VALLEYS. BRISTOL BAY AND THE DELTA WILL BE MOSTLY DRY AND
COLD BY COMPARISON.

.AER/ALU...WATCH/WARNING SUMMARY

PUBLIC...NONE.
MARINE...HEAVY FREEZING SPRAY BRISTOL BAY (AREA 160) TONIGHT AND
FRIDAY.
STORM AREA 155 ENDS BY THIS EVENING.
GALE AREAS 132 138 150 165 170 179 185.

FIRE WEATHER...NONE.

D PERCY APR 13