Small Craft Advisory 133, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM AST MON FEB 5 2007

.DISCUSSION...
THE MAIN SYSTEM IS THE STORM CENTER LOCATED SOUTH OF THE CENTRAL
ALEUTIANS AND ITS FRONT THAT HAS MOVED THROUGH THE CHAIN TO THE FALSE
PASS AREA. ALONG THE FRONT IN THE SOUTHEAST TO EAST FLOW WARM AIR IS
ENTRENCHED ACROSS THE ALEUTIANS AND BERING SEA. WEST OF THIS IS THE
DEEPER COLD AIR OVER THE KAMCHATKA PENINSULA INTO THE SIBERIAN
REGION. A MAJOR UPPER CENTER IS OVER CENTRAL ASIA AND IS EXPECTED TO
DROP TO THE SOUTH AND EAST ACROSS THE KAMCHATKA PENINSULA INTO THE
WESTERN BERING SEA AND EXTREME WESTERN ALEUTIANS BY THIS COMING
WEEKEND. THE UPPER LEVEL LOW AND TOUGH WILL PUSH ACROSS THE ALEUTIAN
CHAIN TO THE ALASKA PENINSULA SUNDAY BRINGING WITH IT THE COLD AIR.
THE CURRENT SET OF NUMERICAL OUTPUT HAS TEMPERATURES DROPPING AROUND
5 DEGREES F FOR ALEUTIAN AND BERING SEA STATIONS.

ACROSS THE HEMISPHERE WE HAVE OUR HUDSON BAY UPPER CENTER AND DEEP
COLD AIR. AS THE WEEK PROGRESSES WE EXPECT AN UPPER LOW TO FORM OVER
THE SOUTHERN YUKON TERRITORY. THIS CENTER AND THE COLD AIR ASSOCIATED
WITH IT WILL MOVE INTO THE EASTERN MAINLAND OF ALASKA BY FRIDAY.
ENSEMBLES ARE IN AGREEMENT ON THE MAJOR FEATURES THROUGH FRIDAY AS
WELL AS EUROPEAN CENTER MODELS.

SURFACE EAST OF THE ALASKA RANGE...HIGH PRESSURE REMAINS IN TACT OVER
THE INTERIOR WITH TRAPPED LOW LEVEL MOISTURE. SOME MID LEVEL MOISTURE
SPREADING OVER THE NORTHERN GULF COAST. BELIEVE THIS WILL REMAIN OVER
THE GULF COAST AREA. A FRONT FROM THE LOW IN THE BERING TO REACH TO
KODIAK ISLAND LATER TONIGHT WITH PRECIPITATION AND MODERATE WINDS.
HIGH PRESSURE TO REMAIN IN PLACE OVER THE MAINLAND THROUGH THURSDAY
WITH THE FRONT STATIONARY OVER KODIAK. THE HIGH SHIFTS INTO THE YUKON
WEDNESDAY AFTERNOON ALLOWING MORE CLOUDINESS INTO THE NORTHERN GULF
COAST AND KENAI PENINSULA. AN UPPER LEVEL LOW SITS OVER THE AREA AT
THIS TIME. THIS PATTERN TO REMAIN INTO FRIDAY. THIS MAY DRAW SOME
PRECIPITATION CHANCES FURTHER INLAND BY FRIDAY.

SURFACE WEST OF THE ALASKA RANGE...STRONG FRONT EXTENDING FROM THE
ALASKA PENINSULA TO EASTERN SIBERIA WITH GOOD JET SUPPORT. COMBINED
WITH HIGH PRESSURE OVER THE MAINLAND...A GOOD GRADIENT EXISTS OVER
THE EASTERN BERING AND EASTERN ALEUTIANS TO THE WEST COAST OF ALASKA.
THE LOW WILL CONTINUE TO WEAKEN NEAR ADAK AND CROSS THE CHAIN LATE
TONIGHT AND HEAD TO THE PARENT LOW JUST EAST OF THE KAMCHATKA
PENINSULA. THE ASSOCIATED FRONT WILL DISSIPATE AS IT MOVES INLAND
TOMORROW MORNING...SO WILL NOT SEE ANY PRECIPITATION TOO FAR INLAND.
ANOTHER SHORT WAVE TROUGH TO MOVE NORTH IN THE FLOW THROUGH THE
CENTRAL ALEUTIANS TUESDAY AND CREATE A FRONTAL BOUNDARY NORTH SOUTH
THROUGH THE CENTRAL BERING INTO THURSDAY MORNING. MEANWHILE...A NEW
LOW ROTATES INTO THE WESTERN ALEUTIAN CHAIN WEDNESDAY NIGHT. THIS LOW
ROTATES TOWARD THE KAMCHATKA PENINSULA FRIDAY WITH A FRONT PUSHING
THROUGH THE BERING THURSDAY AND FRIDAY. WINDS WILL NOT BE THAT STRONG
AFTER TODAYS FRONTAL STRUCTURE BEGINS TO WEAKEN TONIGHT.
PRECIPITATION TO SPREAD INTO SOUTHWEST ALASKA FRIDAY FROM A
PREFRONTAL SHORT WAVE PUSHING MOISTURE OFFSHORE INLAND AND PROVIDING
SOME LIFT TO THE MOISTURE.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALE 150 160 165 170 179 180 185
FIRE WEATHER...NONE

SA/JN FEB 07