Small Craft Advisory 238, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AST SAT MAR 19 2005

.DISCUSSION...

.ANALYSIS...STRONG CONCENTRIC UPPER RIDGE CENTERED OVER SOUTHWEST
ALASKA IS PROVIDING ANOTHER CALM AND CLEAR NIGHT ACROSS MOST OF
MAINLAND ALASKA. 1029 MB SURFACE HIGH LOCATED NEAR AUGUSTINE ISLAND
AND A 1045 MB HIGH CENTERED OFF THE NORTHWEST ALASKA COAST. WITH
STRONG SUBSIDENCE AND LIGHT WINDS TEMPS ACROSS THE SOUTHERN MAINLAND
HAVE COOLED TO SINGLE DIGITS TO THE 20S. CLOSED LOW NEAR 44N 169W IS
SINKING SOUTHWARD AND OLD FRONTAL BOUNDARY OVER CENTRAL BERING HAS
FALLEN APART. THERE ARE STILL A FEW SHOWERS ALONG THE AKPENN AND
EASTERN ALEUTIANS ALONG WITH SOME LOW CLOUDS AND FOG. THERE IS A
DRYING TREND OVER THE EASTERN BERING AS RIDGE MOVES WESTWARD AND
LOW SOUTH OF ALEUTIANS MOVES FARTHER AWAY. A STRONG FRONTAL BOUNDARY
EXTENDING FROM A 973 MB LOW OVER KAMCHATKA IS TRACKING TOWARD THE
WESTERN ALEUTIANS.

.SOUTHERN MAINLAND FORECAST...MODELS REMAIN IN EXCELLENT AGREEMENT
AND WIND EVENT LOOKS TO BE ON TRACK FOR SATURDAY NIGHT THROUGH
SUNDAY NIGHT. UPPER HIGH WILL RETROGRADE WESTWARD AND ELONGATE
NORTH-SOUTH OVER THE BERING SEA TODAY AND SUNDAY. A STRONG SHORT-WAVE
WILL THEN DROP SOUTHWARD ACROSS THE EASTERN HALF OF THE STATE
SATURDAY NIGHT AND SUNDAY FOLLOWED BY A DEEP LAYER OF ARCTIC AIR.
MODELS INDICATE SOME BAGINESS OVER THE GULF AS THIS SHORT-WAVE DROPS
SOUTHWARD BUT DO NOT ACTUALLY DEVELOP A SURFACE LOW UNTIL SUNDAY AND
QUICKLY TRACK THIS SOUTHWARD. THE MAIN LOW IS OFF THE BRITISH
COLUMBIA COAST WITH A HIGH CENTERED NORTH OF THE STATE. THE UPPER JET
CURVING AROUND THE UPPER HIGH (CENTERED OVER THE BERING) IS NOT THAT
IMPRESSIVE AT 95 KTS OR SO. FLOW ACROSS THE ALASKA RANGE IS INITIALLY
PERPENDICULAR BUT QUICKLY VEERS TO A MORE EASTERLY COMPONENT ON
SUNDAY NIGHT AS SHORT-WAVE MERGES WITH SOUTHEAST ALASKA LOW AND
ELONGATES EAST-WEST. ALL THIS EVIDENCE POINTS TO A 12 TO 18 HOUR
EVENT OF ADVISORY LEVEL WINDS. EXPECT WINDS TO INCREASE TONIGHT
AND PEAK DURING THE DAY SUNDAY BEFORE DIMINISHING SUNDAY NIGHT.
HIGHEST WINDS EXPECTED THOMPSON PASS/COPPER RIVER DELTA/MATANUSKA
VALLEY/BROAD PASS. EXPECT HIGH END ADVISORIES IN THESE LOCALS. WILL
PUT LOW END ADVISORIES FOR VALDEZ/COPPER RIVER BASIN/SUSITNA
VALLEY/ANCHORAGE. STRONGEST WINDS FOR ANCHORAGE ZONE WILL OCCUR
ALONG KNIK ARM. AS ADVERTISED THERE WILL BE AREAS OF BLOWING DUST
WHICH MAY REDUCE VISIBILITIES TO AROUND 1 NM AT TIMES. WILL ISSUE
A WSW TO HIGHLIGHT THIS WIND EVENT FOR THE HIGH POPULATION AREAS.

EXPECT A QUICK WARMING UP THROUGH MID WEEK AS CLOSED LOW MOVES TO
THE BERING AND SOUTHEASTERLY FLOW DOMINATES ACROSS THE REGION. THE
EXTENDED IS A FLIP FROM YESTERDAY. INSTEAD OF RIDGE SETTING BACK UP
OVER WESTERN CANADA THE GFS IS INDICATING RIDGE HOLDING OVER THE
ARCTIC OCEAN AND SHORT-WAVES DROPPING SOUTHWARD ACROSS ALASKA
ALONG WITH COLD AIR. HAVE VERY LOW CONFIDENCE IN THIS.

BERING SEA REGION FORECAST...UPPER RIDGE WILL PROVIDE DRY CONDITIONS
OVER THE EASTERN BERING THROUGH SUNDAY NIGHT. CLOSED LOW WILL THEN
MOVE FROM GULF TO BERING MONDAY AND TUESDAY BRING A CHANCE OF SHOWERS
BUT NO MAJOR STORMS. WESTERN BERING FRONT WILL MOVE TO THE WESTERN
ALEUTIANS BY THIS AFTERNOON AND THEN GRIND TO A HALT AS IT NEARS THE
UPPER RIDGE. A LOW WILL DEVELOP ALONG THE FRONT BUT REMAIN WELL SOUTH
OF THE ALEUTIANS AS THE BERING RIDGE RETROGRADES EVEN FURTHER
WESTWARD SUNDAY NIGHT AND MONDAY. EXTENDED LOOKS WETTER AS UPPER LOW
SETS UP SHOP OVER THE BERING. HOWEVER...DOES NOT APPEAR TO BE ANY
MAJOR STORMS ON THE HORIZON.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...WIND ADVISORY 101 111 121 131 135 141 145 191.
MARINE...GALES 2B1 2C 2C4 3A 3C 4 5A 13B.

SEB MAR 05