Small Craft Advisory 70, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM AST FRI JAN 25 2008

.ANALYSIS...LOW OVER THE EASTERN GULF BROUGHT PLENTY OF SNOWFALL TO
SOUTH CENTRAL ALASKA LAST NIGHT. A SHORT WAVE IS WESTERLY FLOW BEHIND
THE SYSTEM CONTINUES TO BRING LIGHT SNOW TO THE AREA TODAY. COLD AIR
FILTERING IN OVER THE MAINLAND TODAY. THE LOW WILL REMAIN IN THE
NORTHEAST GULF TONIGHT AND PULL OFF TOMORROW. CLEARING SHOULD START
IN EARNEST OVER MUCH OF THE MAINLAND AND SOUTH CENTRAL THIS EVENING.
THE LOW SOUTH OF THE KAMCHATKA PENINSULA PUSHING A STRONG FRONT
ACROSS THE WESTERN ALEUTIANS THIS AFTERNOON AND EVENING. THE FRONT TO
MOVE INTO THE CENTRAL ALEUTIANS TONIGHT AND TOMORROW. THIS WILL PUSH
THE COLD AIR NORTH ONCE AGAIN OVER THE BERING.

.MODEL DISCUSSION...MODELS HANDLE THE LOW OVER THE GULF VERY SIMILAR
OVER THE NEXT COUPLE DAYS AND SLIDE IT SOUTHEAST TO THE PACIFIC
NORTHWEST SUNDAY MORNING. THE HIGH PRESSURE OVER THE EASTERN BERING
AND EASTERN SIBERIA TO SHIFT OVER THE GULF AND MAINLAND SATURDAY AND
BE PUSHED OUT OF THE AREA SUNDAY NIGHT. THIS MOVEMENT IS ALL DRIVEN
BY A LARGE LOW PRESSURE SYSTEM SOUTH OF THE KAMCHATKA PENINSULA
CURRENTLY. THIS LOW TO PROGRESS INTO THE WESTERN BERING SATURDAY
AFTERNOON AND SETTLE INTO THE WESTERN BERING THROUGH MONDAY.
DIFFERENCES START TO BEGIN MONDAY NIGHT BETWEEN MODELS. THE
DIFFERENCE IS FROM RUN TO RUN AND BETWEEN THE MODELING CENTERS. A
STRONG SHORT WAVE TO MOVE ACROSS THE CENTRAL BERING MONDAY NIGHT AND
TO THE KUSKOKWIM DELTA TUESDAY WITH THE GFS SOLUTION WHILE ANOTHER
PIECE STAYS WELL SOUTH OF THE ALEUTIANS AND MOVES INTO THE GULF
TUESDAY NIGHT. THE ECMWF AND UKMET KEEP A MODERATED SOLUTION WITH ONE
LOW MOVING TO THE CHAIN AND SLIDING INTO THE GULF WEDNESDAY. MORE
DIFFERENCES RESULT IN THE BERING AS WELL FROM THIS SCENARIO.
THEREFORE...THE UNCERTAINTY RAISES BEYOND TUESDAY AFTERNOON AND WE
HAVE CHANGED LITTLE IN THE FORECAST AS A RESULT.

AT THE UPPER LEVELS...A TROUGH REMAINS OVER THE KAMCHATKA AREA
THROUGH SUNDAY WITH SOME LOW AMPLITUDE RIDGE OVER THE EASTERN BERING
AND GULF. THE FLOW BECOMES MUCH MORE ZONAL MONDAY NIGHT THROUGH
WEDNESDAY. THE TROUGH RE-ESTABLISHES THURSDAY NEAR KAMCHATKA AND
REMAINS THROUGH THE WEEK.

.SHORT TERM FORECAST...
SOUTH AND EAST OF THE ALASKA RANGE...THE LOW IN THE NORTHEAST GULF TO
DEEPEN THIS AFTERNOON AND EVENING AND REMAIN IN THE NORTHERN GULF
THROUGH TONIGHT AND TOMORROW. HIGH PRESSURE TO BUILD OVER THE
MAINLAND AS WELL WITH COLD AIR ADVECTION IN NORTHWEST FLOW. THE FRONT
SIDE OF THE UPPER RIDGE TO MOVE ACROSS THE AREA TONIGHT WITH A STRONG
JET. THIS WILL INCREASE NORTHERLY FLOW OVER THE AREA. GALES TO STORMS
WILL BE PRESENT OVER THE MARINE AREAS. WITH ALL THESE FACTORS...WE
HAVE ISSUED MANY WIND HEADLINES. THE BEST SPOT FOR WARNING IS THE
THOMPSON PASS AND COPPER RIVER DELTA AREAS. THESE CONDITIONS TO
LESSEN SATURDAY AFTERNOON AS THE LOW PUSHES TO THE QUEEN CHARLOTTE
ISLANDS. OTHER AREAS WILL BE DRY AND COLD WITH SOME BREEZY
CONDITIONS. COLD AND DRY CONDITIONS TO REMAIN THROUGH SUNDAY EXCEPT
KODIAK. THE LOW IN THE BERING PUSHES A FRONT TO KODIAK SUNDAY AND
WARMS THEM A BIT. THE FRONT TO GRADUALLY MOVE NORTH SUNDAY/SUNDAY
NIGHT. THE FRONT WEAKENS MONDAY WITH PRECIPITATION SLIDING INTO SOUTH
CENTRAL.

WESTERN MAINLAND AND ALASKA PENINSULA...COLD WESTERLY FLOW CURRENTLY
OVER THE AREA. CLEARING TO TAKE PLACE THIS EVENING. SOME BREEZINESS
TO REMAIN NEAR BRISTOL BAY THROUGH TONIGHT. OTHERWISE...WINDS WILL
BEGIN TO LIGHTEN. THEREFORE...WITH THE SNOW FROM LAST NIGHT AND THIS
MORNING...MAY SEE SOME AREAS OF FOG. A FRONT FROM THE LARGE BERING
LOW TO REACH THE AKPEN AND COAST SATURDAY EVENING. EXPECT ENOUGH WIND
AND NOT ENOUGH WARMING...SO WILL ISSUE BLIZZARD WATCH FOR THE
KUSKOKWIM COAST SATURDAY NIGHT. A MIX OF RAIN AND SNOW ELSEWHERE. THE
FRONT PUSHES INLAND SUNDAY BUT WEAKENS CONSIDERABLY. TEMPERATURES
WILL DEFINITELY WARM WITH THIS FRONT BUT NOT ABOVE FREEZING INLAND.
MOIST WESTERLY FLOW TO REMAIN OVER THIS REGION THROUGH MONDAY WITH
SNOW SHOWERS.

BERING/ALEUTIANS/PRIBILOFS...RAIN AND SNOW ALONG THE STRONG FRONT
OVER THE WESTERN BERING. GOOD WARM ADVECTION WITH THIS FRONT...SO DO
NOT EXPECT ANY BLIZZARD CONDITIONS EVEN AT THE PRIBILOFS. THE ANCHOR
LOW REMAINS IN THE WESTERN BERING THROUGH MONDAY AS THE FRONT PUSHES
TO THE COAST SATURDAY EVENING WEAKENING ALONG THE WAY. BEHIND THE
LOW...SNOW SHOWERS WILL BE PREVALENT WITH MODERATE WINDS.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNING ZONE 131.
         BLIZZARD WATCH ZONE 155
MARINE...STORM 176
         GALE 120 121 125 129 130 132 138 150 172 175 179 185
         HEAVY FREEZING SPRAY 121 129 130 141 185
FIRE WEATHER...NONE

JN JAN 08