Gale Warning 330, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
1230 PM AKDT SAT APR 3 2010

.ANALYSIS AND UPPER LEVELS...A 175 KNOT UPPER JET IS NEARLY ZONAL
AS IT RIDES ALONG THE ALEUTIANS OVER TOP OF A LOW AMPLITUDE
LONG-WAVE RIDGE CENTERED OVER THE NORTH CENTRAL PACIFIC. THE JET
THEN DIVES SOUTHEASTWARD AS IT NEARS THE GULF...MOVING AROUND THE
BOTTOM OF A HIGH AMPLITUDE SHORT-WAVE TROUGH. THERE ARE A COUPLE
LOWS OVER THE BERING TRACKING RAPIDLY TO THE EAST IN THIS FAST
FLOW. A WEAK VERTICALLY STACKED LOW OVER THE SOUTHERN GULF IS
NEARLY STATIONARY. A WEAK UPPER TROUGH MOVING THROUGH SOUTHWEST
ALASKA IS PRODUCING CLOUDS AND A FEW SHOWERS WHILE MOST OF
SOUTHCENTRAL IS ENJOYING A SUNNY DAY.

.MODEL DISCUSSION...THE GFS IS SLOWER THAN OTHER SOLUTIONS IN
MOVEMENT OF GULF LOW TO THE SOUTHERN KENAI PENINSULA AND THE UKMET
IS FARTHER SOUTH THAN THE OTHER SOLUTIONS...SO PREFER THE NAM/EC
HANDLING OF THIS LOW. ELSEWHERE...MODELS ARE IN SURPRISINGLY
GOOD AGREEMENT WITH TRACK OF BERING LOWS THROUGH THE SHORT-TERM.

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...NORTHEAST PACIFIC TROUGH WILL SHIFT EASTWARD
THE NEXT COUPLE DAYS ALLOWING THE UPPER JET TO EXTEND EASTWARD INTO
THE GULF. THIS WILL LEAD TO THE DEVELOPMENT OF A NEW SHORT-WAVE
TROUGH WHICH WILL SWING NORTHWARD TOWARD SOUTHCENTRAL
SUNDAY...PULLING THE LOW OVER THE GULF NORTHWESTWARD TO THE KENAI
PENINSULA BY LATE SUNDAY AND BRINGING PRECIP MAINLY TO COASTAL
LOCATIONS. AN UPPER LOW WHICH IS NOW OVER THE NORTHERN BERING WILL
THEN ELONGATE EASTWARD TO SOUTHCENTRAL MONDAY. MULTIPLE WAVES WILL
CONTINUE TO ROTATE AROUND THIS UPPER CENTER BRINGING PREDOMINANTLY
SHOWERS TO THE REGION THROUGH AT LEAST MID WEEK...WITH MOST OF THE
ACTIVITY REMAINING ALONG COASTAL AREAS. ALTHOUGH SKY COVER WILL
GENERALLY BE MOSTLY CLOUDY THERE WILL CERTAINLY BE BREAKS OF SUN
IN BETWEEN THE UPPER WAVES.

SOUTHWEST ALASKA...THE SHORT-WAVE MOVING ACROSS THE REGION TODAY
WILL EXIT TO THE NORTH TONIGHT. HOWEVER...AS THE UPPER LOW
TRANSITIONS EASTWARD THE NEXT FEW DAYS UPPER WAVES WILL CONTINUE
TO MOVE ACROSS THE REGION RESULTING IN MOSTLY CLOUDY SKIES AND
OCCASIONAL SHOWERS.

BERING SEA/ALEUTIANS...STRONG UPPER JET WILL REMAIN IN PLACE
THROUGH THE SHORT-TERM...SO SYSTEMS WILL CONTINUE TO QUICKLY
MOVE THROUGH RESULTING IN GENERALLY SHORT DURATIONS OF PRECIPITATION
AND STRONG WINDS.

.LONG TERM FORECAST...HEMISPHERIC FLOW LOOKS TO BE VERY PROGRESSIVE
THROUGH THE EXTENDED FORECAST PERIOD. THE UPPER JET ALSO LOOKS LIKE
IT WILL REMAIN AT A SIMILAR LATITUDE. THEREFORE...EXPECT AN ACTIVE
STORM PATTERN ALONG THE ALEUTIANS AND INTO THE GULF WITH WEATHER
CHANGING EVERY DAY OR TWO....WHICH IS QUITE COMMON HEADING INTO
SPRING. OF COURSE...WITH THIS TYPE OF FLOW IT IS DIFFICULT FOR
MODELS TO LATCH ON TO SPECIFIC STORMS VERY FAR OUT...SO FORECAST
UNCERTAINTY QUICKLY GROWS AS WE HEAD THROUGH NEXT WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING...120 125 155 165 170 172 175 176.
FIRE WEATHER...NONE.

SEB APR 10