FXAK68 PAFC 102210
AFDAFC
AREA FORECAST DISCUSSION 
SOUTHCENTRAL AND SOUTHWEST ALASKA
300 PM AKDT FRI OCT 10 2008
.ANALYSIS...THE PARENT LOW SOUTH OF COLD BAY WITH A TRIPLE POINT LOW
MOVING NORTH JUST WEST OF ANCHORAGE HAS CREATED A SEVERE WIND EVENT
OVER THE ANCHORAGE AREA STARTING LAST NIGHT AND REMAINING THROUGH
EARLY THIS AFTERNOON. WINDS HAVE BACKED OFF LATE THIS MORNING...BUT
GUSTS TO 100 MPH WERE REPORTED EARLY THIS MORNING. THE FRONT HAS
PASSED AND AREAS OF SNOW IN THE SUSITNA VALLEY ARE NOW RAIN AND MOST
AREAS IN THE COPPER RIVER BASIN ARE ABOVE FREEZING AS WELL. ON THE
BACK SIDE OF THIS LARGE SYSTEM...STRONG NORTHERLY WINDS AND COLD AIR
FILTERING OVER THE CENTRAL AND EASTERN BERING. AS THE LOW MOVES EAST
THIS AFTERNOON...COLDER AIR FILTERING INTO KUSKOKWIM DELTA AND VALLEY
CHANGING AREAS THAT WERE A RAIN/SNOW/FREEZING RAIN MIX TO ALL SNOW.
HIGH PRESSURE OVER THE WESTERN BERING WITH MODERATE NORTHERLY WINDS.
.UPPER LEVELS...4 WAVE PATTERN TRANSITIONING INTO A 3 WAVE BY EARLY
NEXT WEEK. THEREFORE...THE AIR MASS WILL BE CHANGING OVER THE REGION.
 
THE BERING WILL HAVE A BRIEF WARM UP THIS WEEKEND BUT SAG BACK INTO
THE COLD BY MID WEEK AS THE LONG WAVE TROUGH SETTLES BACK INTO THE
AREA. IN THE MEANTIME...THE TROUGH OVER THE EASTERN BERING TO LIFT
INTO THE GULF AND OVER THE YUKON AS A RIDGE TRANSITIONS OVER THE
BERING THIS WEEKEND. A STRONG SHORT WAVE MOVES THROUGH THE BERING
SUNDAY AND MONDAY AND RESETTLES THE TROUGH OVER THE AREA EASTERN
BERING BY MID WEEK. THE WARM AIR OVER SOUTH CENTRAL TO BECOME COLD AS
THE TROUGH MOVES OVER SOUTH CENTRAL BY SUNDAY NIGHT.
.MODEL DISCUSSION...ALL MODELS IN GOOD AGREEMENT THROUGH THE FIRST
FEW DAYS. THE STACKED LOW SOUTH OF COLD BAY TO ROTATE INTO THE GULF
DRAGGING COLDER AIR BEHIND IT FOR SATURDAY ACROSS WESTERN ALASKA. A
LOW STAYS IN THE GULF THROUGH THE WEEKEND AND THEN IS PUSHED OUT BY A
SHORT WAVE RIDGE THAT MOVES THROUGH THE BERING THIS WEEKEND. BEHIND
THIS RIDGE IS A STRONG FRONT FROM A LARGE UPPER LEVEL LOW NEAR
KAMCHATKA. THE PATTERN BECOMES MORE PROGRESSIVE AT THIS POINT AND A
FEW LOWS ROTATE THROUGH THE BERING INTO THE GULF WITH A TROUGH ENDING
UP DIGGING OVER THE EASTERN BERING ONCE AGAIN BY MID WEEK.
.SHORT TERM FORECAST...
SOUTH CENTRAL...HIGH WINDS PUSHED THROUGH THE AREA LAST NIGHT AND
THIS MORNING. GUSTS TO 100 MPH WERE REPORTED. THE FRONT MOVED THROUGH
ANCHORAGE AROUND 10AM WHEN WINDS BEGAN TO DIMINISHING SLOWLY.
MODERATE TO STRONG WINDS TO CONTINUE OUT OF THE SOUTH SOUTHEAST AS
THE PARENT LOW IS STILL WORKING NORTH TO KODIAK TONIGHT. IN
ADDITION...THE BARRIER JET ALONG THE NORTHERN GULF COAST TO REMAIN
WITH THE FRONT THROUGH LATE THIS AFTERNOON. STORM FORCE WINDS ARE
THROUGH THE NORTHERN GULF COAST AND PRINCE WILLIAM SOUND TODAY. THE
LOW TO MOVE TO THE KENAI PENINSULA SUNDAY. THE WARM AIR RUSHED IN
WITH THIS FRONT TODAY. MOST AREAS ARE ABOVE FREEZING RIGHT NOW. DO
NOT ANTICIPATE ENOUGH CLEARING TONIGHT FOR WIDESPREAD FOG. STILL SEE
ENOUGH INSTABILITY FOR SHOWERS THROUGH THE WEEKEND. THE MAIN TROUGH
TO INCH EAST AND ACROSS THE AREA SUNDAY. THIS WILL LIKELY BRING A
COLD AIR BOUNDARY CLOSE TO ANCHORAGE SUNDAY. IT MAY SWING EAST ENOUGH
FOR SNOW TO COME BACK TO ANCHORAGE SUNDAY AFTERNOON/NIGHT. THE SYSTEM
TO MOVE OUT OF THE AREA MONDAY AS A FRONT REACHES THE WEST COAST AND
KODIAK AND PUSHES HIGH PRESSURE OVER THE AREA.
WEST OF THE ALASKA RANGE...FREEZING RAIN OCCURRED FOR SEVERAL HOURS
THIS MORNING NEAR BETHEL. THIS HAS STOPPED AS COLDER AIR HAS FILTERED
INTO THE REGION. HOWEVER...ENOUGH WARM AIR IN BRISTOL BAY FOR RAIN.
THE KUSKOKWIM VALLEY WAS IN A MIX WITH NO REPORTS OF FREEZING RAIN OR
DRIZZLE. SOME SNOW FELL TO THE NORTH AND WEST WITH AREAS SOUTH OF
SLEETMUTE MOST LIKELY IN A MIX. COLD AIR TO CONTINUE TO SLIP EAST
TONIGHT AND TOMORROW. THEREFORE...MAY SEE SOME AREAS OF FREEZING RAIN
IN BRISTOL BAY TOMORROW. COLD AIR IN PLACE BY SATURDAY EVENING
THOUGH. MODERATE NORTHERLY WINDS TO CONTINUE BEHIND THIS LOW
ESPECIALLY ALONG THE COAST. WITH THE NEW SNOW...SOME AREAS WILL HAVE
REDUCED VISIBILITIES IN BLOWING SNOW. DO NOT ANTICIPATE THAT ENOUGH
OR ENOUGH SNOW TO FALL FOR A BLIZZARD CONDITIONS AT THIS TIME. HIGH
PRESSURE TO MOVE OVER THE AREA SUNDAY IN ADVANCE OF A WARM FRONT. THE
FRONT TO REACH THE COAST MONDAY WITH PRECIPITATION CHANGING TO RAIN
WITH THE ADVANCE OF THE FRONT. WINDS WILL BE NEAR GALE FORCE WITH
THIS FRONT.
.ALEUTIANS AND BERING SEA...STRONG NORTHERLY WINDS CONTINUE BEHIND
THE LARGE LOW OVER WESTERN AND SOUTH CENTRAL ALASKA. SHOWERS TO
CONTINUE AS WELL. HIGH PRESSURE OVER THE WESTERN ALEUTIANS TO MOVE
ACROSS THE BERING AND INLAND BY MONDAY. A VIGOROUS FRONT TO MOVE
ACROSS THE WESTERN BERING SUNDAY AND GENERALLY HOLD ITS OWN AS IT
MOVES TO THE EASTERN BERING BY SUNDAY NIGHT. GALE FORCE WINDS AND
RAIN TO MOVE WITH THIS FRONT.
.LONG TERM FORECAST...MOST MODELS AGREE WITH THE GENERAL TRANSITION
OF THE PATTERN. THE FORECAST GENERALLY FOLLOWS A PATTERN WITH A
COUPLE LOW MOVING THROUGH THE BERING INTO THE GULF AND THEN A LONG
WAVE TROUGH DEVELOPING OVER THE EASTERN BERING BY MID WEEK.
THEREFORE...A FEW PRECIPITATION EVENTS TO FOLLOW THE LOWS THROUGH
EARLY IN THE WEEK WITH A DRIER PATTERN TOWARDS THE END OF THE WEEK
WITH A CLOSED LOW SETTING UP SOUTH OF THE ALASKA PENINSULA.
.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...SMALL STREAM FLOOD ADVISORY 125 131 135
MARINE...GALE 120 125 150 155 160 165 170 171 172 175 179 180 185
FIRE WEATHER...NONE
NELSON OCT 08