Small Craft Advisory 152, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AST FRI FEB 17 2006

.DISCUSSION...

MODELS ARE IN GOOD AGREEMENT IN THE SHORT TERM.  GFS SOLUTION WAS
USED OVER BOTH DOMAINS FOR A BETTER INITIALIZATION.

UPPER LEVELS...THE DOMINANT FEATURE CONTINUES TO BE A HIGH AMPLITUDE
RIDGE THAT EXTENDS FROM THE GULF OF ALASKA NORTHEASTWARD INTO YUKON
TERRITORY.  A SHORTWAVE TROUGH OVER THE CENTRAL ALEUTIANS WILL PUSH
EASTWARD...AND BY SATURDAY EVENING...WILL HAVE DEGRADED THE EAST
ALASKA RIDGE.  THE SHORTWAVE WILL FORM A CLOSED LOW FRIDAY
NIGHT...BUT SHOULD QUICKLY CUT ITSELF OFF FROM THE FLOW.  BY
SUNDAY...THE UPPER FLOW WILL BECOME HIGHLY ZONAL...AND A STRONG 150
KT JET CORE WILL HOVER THE CENTRAL ALEUTIANS.

A HIGH CLOUD FEATURE OVER THE GULF...EASILY VISIBLE ON IR
SATELLITE...IS NOT BEING HANDLED WELL BY ANY OF THE MODELS.  RADAR
SUGGESTS THAT PRECIPITATION WILL BE MINIMAL AND BE FOCUSED NEAR
PRINCE WILLIAM SOUND.

SURFACE...THE HIGH PRESSURE THAT HAS KEPT THE EASTERN DOMAIN
RELATIVELY QUIET THE LAST FEW DAYS IS GRADUALLY PUSHING EASTWARD INTO
CANADA BY LATE FRIDAY.  A LOW IN THE CENTRAL BERING IS TRACKING
NORTHWARD AND WILL MOVE ONSHORE TO SIBERIA FRIDAY EVENING.  STRONG
WINDS ARE EXPECTED AHEAD OF ITS ASSOCIATED FRONT.  A QUICK MOVING LOW
PRESSURE SYSTEM CURRENTLY WELL SOUTHWEST OF SHEMYA WILL MOVE INTO THE
BERING BY FRIDAY EVENING...AND ONSHORE NEAR THE SEWARD PENINSULA BY
SATURDAY MORNING.  THE FRONT ASSOCIATED WITH THE SECOND LOW WILL
INCREASE THE LIKELIHOOD FOR PRECIPITATION IN THE EASTERN DOMAIN
FRIDAY EVENING AND INTO SATURDAY...BEFORE IT STRETCHES ITSELF APART
OVER SOUTHCENTRAL BY SUNDAY MORNING.  STRONG WINDS WILL DEVELOP ALONG
THE TURNAGAIN ARM AS THE TWO LOWS CHANGE THE PRESSURE GRADIENT
ORIENTATION.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALES 130 138 155 160 165 170 171 172 176 180 185 410.
      ...STORMS 175 179 410.
TGD FEB 06