Small Craft Advisory 131, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM AST SUN FEB 4 2007

.DISCUSSION...
A SLOWLY WEAKENING LOW PRESSURE SYSTEM REMAINS TO BE THE DOMINANT
WEATHER FEATURE AFFECTING THE FORECAST AREA. THE LOW IS EXPECTED TO
REMAIN NEARLY STATIONARY FOR THE FIRST FEW FORECAST PERIODS. SEVERAL
LOW PRESSURE SYSTEMS WILL WORK THEIR WAY AROUND THE UPPER LONGWAVE
TROUGH THROUGH THE NEXT FEW DAYS.

.MODELS...
ALL THE MODELS INITIALIZED WELL TODAY...BUT THE PROBLEM ARISES MONDAY
AFTERNOON WITH THE ALEUTIAN LOW. BY THIS POINT...BOTH THE UKMET AND
EUROPEAN MODELS WANT TO FORM A DISTINCT SECONDARY LOW IN THE BERING
SEA. THE GFS HAS HAD A SIMILAR SOLUTION THE LAST FEW MODEL RUNS.
HOWEVER WITH THIS MORNINGS RUNS BOTH THE GFS AND NAM NOW WANT A BROAD
AREA OF LOW PRESSURE INSTEAD OF TWO LOWS DURING THIS TIME PERIOD. THE
GFS ENSEMBLE MEAN TENDS TO AGREE WITH THE OPERATIONAL GFS THOUGH
THERE IS STILL CONSIDERABLE DISPARITY BETWEEN INDIVIDUAL ENSEMBLE
MEMBERS. WENT WITH THE CURRENT GFS RUN...BUT IT WILL BE INTERESTING
TO SEE HOW THE MODELS LOOK WITH THE 00Z RUNS.

.UPPER AIR...
THE HEMISPHERIC THREE-WAVE PATTERN LOOKS TO REMAIN RELATIVELY
UNCHANGING THE NEXT SEVERAL DAYS. A 170 KT JET STREAM CONTINUES A
ZONAL TRACK ALONG THE 30N LATITUDE LINE. A NEGATIVELY TILTED CLOSED
LOW IS STACKED ON TOP OF THE WESTERN ALEUTIAN SURFACE LOW. THIS LOW
WILL GET ABSORBED BACK INTO THE LARGER SCALE LONGWAVE BY TUESDAY. THE
OMEGA BLOCK THAT HAS REMAINED FIRMLY IN PLACE OVER MAINLAND ALASKA
AND WESTERN CANADA OVER THE LAST SEVERAL DAYS WILL CONTINUE TO STEER
LOW PRESSURE SYSTEMS TOWARDS THE ALEUTIANS AND THE WESTERN
CONTINENTAL STATES FOR THE FORECAST PERIOD.

.EAST OF THE ALASKA RANGE...
THE REMNANTS OF A DYING LOW PRESSURE SYSTEM OVER SOUTHEAST ALASKA
WILL DISSIPATE TONIGHT AND INTO TOMORROW. HIGH PRESSURE WILL CONTINUE
TO DOMINATE THE WEATHER FOR SEVERAL DAYS. A FAIR PRESSURE GRADIENT
WILL KEEP CONDITIONS MODERATELY WINDY THROUGH NORTH-SOUTH ORIENTED
GAPS...ALTHOUGH IT IS UNLIKELY STRONG WIND HEADLINES WILL BE
NECESSARY. FOG WILL REMAIN A CONCERN OVERNIGHT IN MANY AREAS AS LOW
LEVEL MOISTURE REMAINS FROM THE RECENT WARM SPELL. A SLIGHT COOLING
TREND LOOKS TO BE IN STORE THROUGH TUESDAY OR SO...ALTHOUGH
RADIATIONAL COOLING WILL BE KEPT IN CHECK BY LINGERING HIGH CLOUDS.
IT DOES NOT APPEAR THAT TEMPERATURES WILL DROP MUCH BELOW
SEASONAL AVERAGE THOUGH. A SHORTWAVE TROUGH WILL MOVE IN LATE TUESDAY
INTO WEDNESDAY...WHICH WILL BRING A CHANCE FOR PRECIPITATION ALONG
WITH ANOTHER MODERATION IN TEMPERATURES. HIGH PRESSURE MOVES BACK IN
FOR THURSDAY THROUGH NEXT WEEKEND.

.WEST OF THE ALASKA RANGE...
AS THE LOW PRESSURE SYSTEM IN THE BERING SEA DISSIPATES OVER THE NEXT
COUPLE DAYS...HIGH WINDS FROM ADAK TO THE WESTERN CAPES OF BRISTOL
BAY WILL GRADUALLY DECREASE. HIGH PRESSURE WILL CONTINUE TO DOMINATE
THE ALASKA MAINLAND THROUGH TOMORROW NIGHT WITH CLEAR AND COOL NIGHT
AND AREAS OF FOG. THE FRONT ASSOCIATED WITH THIS LOW WILL PUSH
NORTHEAST TUESDAY AND MOVE THROUGH SOUTHWEST ALASKA TUESDAY NIGHT.
THE LOW NOW IN THE WESTERN BERING WILL BE ENCIRCLED BY SHOWERS WITH
LIGHT TO MODERATE WINDS. AN UPPER LEVEL WAVE WILL MOVE IN BEHIND THE
FRONT IN THE EASTERN BERING BRINGING ANOTHER SHOT OF PRECIP TO THE
COASTAL AREAS OF SOUTHWEST ALASKA WEDNESDAY. THE NEXT LOW MOVING INTO
THE LONG WAVE TROUGH WILL ARRIVE WEDNESDAY OVER THE WESTERN ALEUTIAN
ISLANDS. THIS LOW MOVES NORTH THROUGH THE WESTERN BERING THURSDAY
WITH A FRONT PUSHING ACROSS THE BERING THURSDAY AND TO THE COAST BY
FRIDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WARNING 185
         DENSE FOG ADVISORY 101
MARINE...STORM 170
         GALE 150 155 165 170 172 175 176 179 180 185
FIRE WEATHER...NONE

DANG FEB 07