Gale Warning 364, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM AKDT MON APR 20 2009

.ANALYSIS AND UPPER LEVELS...
THE STACKED LOWS NEAR KAMCHATKA AND THE GULF WITH A RIDGE OF HIGH
PRESSURE STUCK IN BETWEEN DOMINATE THE WEATHER PATTERN TODAY AND HAVE
FOR THE PAST FEW DAYS. A STRONG FRONT IS MOVING THROUGH THE WESTERN
AND CENTRAL ALEUTIANS TODAY WITH GALE FORCE WINDS AND MODERATE
PRECIPITATION. THE TEMPERATURES ARE WARM WITH THIS FRONT AND SHOULD
PUSH SOME ICE NORTH. THE COLD AIR ASSOCIATED WITH THE GULF LOW WILL
KEEP SOME SHOWERS OVER THE COPPER RIVER BASIN FOR THIS AFTERNOON AND
EVENING BEFORE DRIER AND MORE STABLE AIR MOVES IN TOMORROW. WITH THE
LOW IN THE AREA...GAP WINDS TO BE IN THE FORECAST THROUGH TOMORROW.
LONG WAVE PATTERN BEGINNING TO SHIFT TO THE EAST. THE GULF LOW TO
MOVE OVER CANADA TOMORROW WITH THE RIDGE OVER THE BERING SLIDING TO
THE MAINLAND. THE LOW OVER THE KAMCHATKA TO PUSH INTO THE WESTERN
BERING TONIGHT.

.MODEL DISCUSSION...
MODELS CONTINUE TO BE IN GREAT AGREEMENT FOR THE TRANSITION OF THE
LONG WAVE PATTERN THROUGH THE WEEK AND INTO THE WEEKEND. SOME TIMING
PROBLEMS ON A SYSTEM PUSHING INTO THE WESTERN BERING EARLY NEXT WEEK.
BUT THAT IS SO FAR OUT RIGHT NOW TO COMMENT. AT THE SURFACE...MOST
MODELS ARE IN GREAT AGREEMENT AS WELL. THE ONLY POTENTIAL FLAW IS
THAT THE GFS STAMPS OUT A TRIPLE POINT LOW ON WEDNESDAY NEAR COLD BAY
AND RIDES IT INTO THE SEWARD PENINSULA THURSDAY. THIS IS MORE
AGGRESSIVE THAN OTHER MODELS. FIND IT HARD TO DISAGREE WITH THIS
SCENARIO SINCE A JET WILL BE RIDING UP THE BACKSIDE OF THE RIDGE OVER
THE MAINLAND AT THIS TIME. THE ENERGY WITH THIS JET WILL MOST LIKELY
PRODUCE A LOW AND AS IT MIXES WITH THE COLDER AIR OVER THE ICE
COVERED NORTHERN BERING IT SHOULD DEEPEN.

.SHORT TERM FORECAST...
.SOUTH CENTRAL...
HIGH PRESSURE IN STORE WITH A LOW IN THE SOUTHERN GULF. ENOUGH
INSTABILITY AROUND FOR SHOWERS OVER THE HIGHER TERRAIN IN THE COPPER
RIVER BASIN. SOME WRAPAROUND MOISTURE HITTING KODIAK THIS
MORNING...BUT SHOULD PULL AWAY THIS AFTERNOON. A WEAK AREA OF LOW
PRESSURE TO REMAIN IN THE GULF TOMORROW WITH HIGH PRESSURE MOVING IN
FROM THE WEST. THIS SHOULD PROVIDE SOME GOOD GRADIENTS FOR WESTERLY
AND NORTHERLY GAP FLOWS. HIGH PRESSURE TO MOVE OVER WEDNESDAY.
HOWEVER...WE WILL BE ON THE BACK SIDE OF THE RIDGE. THEREFORE...HIGH
CLOUDS TO MOVE OVER THE AREA LATE WEDNESDAY. SOME SHOWERS MAY SPREAD
TO KODIAK WEDNESDAY AFTERNOON/NIGHT. A SECONDARY WAVE TO MOVE AROUND
THE BERING LOW TO BRING RAIN TO SOUTH CENTRAL THURSDAY
AFTERNOON/NIGHT. AS SKIES CLEAR KODIAK ISLAND COULD SEE NEAR-RECORD
WARM TEMPERATURES ON TUESDAY.

.SOUTHWEST...
SUNNY CONDITIONS TO PREVAIL TODAY. PROBABLY WILL SEE SOME PATCHY FOG
AGAIN TOMORROW MORNING OVER BRISTOL BAY AND KUSKOKWIM DELTA. THE
FRONT MOVING INTO THE CENTRAL ALEUTIANS TO PUSH TO THE COAST TOMORROW
NIGHT. SOME WINDS TO INCREASE ALONG THE COAST AS WELL. PRECIPITATION
TO MOVE INLAND WEDNESDAY AFTERNOON AND EVENING. A LOW TO DEVELOP
ALONG THE FRONT IN BRISTOL BAY WEDNESDAY NIGHT AND PUSH TO THE SEWARD
PENINSULA THURSDAY AFTERNOON. THIS WILL INCREASE PRECIPITATION AND
WINDS IN BRISTOL BAY AND KUSKOKWIM DELTA WEDNESDAY NIGHT THROUGH
THURSDAY.

.BERING SEA/ALEUTIANS...
THE FRONT IN THE CENTRAL ALEUTIANS WILL MOVE ACROSS THE BERING TO THE
COAST BY WEDNESDAY MORNING. STRONGER WINDS ARE EXPECTED TONIGHT INTO
TOMORROW MORNING WITH THE FRONT AS A SHORT WAVE TROUGH ROTATES AROUND
THE UPPER LOW. A JET MAX TO ACCOMPANY THIS VORT MAX AS WELL. THE
UPPER LOW TO ROLL EAST AS WELL THROUGH THE NEXT COUPLE DAYS. SHOWERS
TO REMAIN WITH THE LOW CENTER IN THE WESTERN ALEUTIANS AND BEHIND THE
FRONT THROUGH THURSDAY.

.LONG TERM FORECAST...OVERALL...A BROAD SOUTHWEST FLOW TO REMAIN OVER
THE MAINLAND THURSDAY WITH A RIDGE BUILDING FRIDAY FOLLOWED BY A
RETURN TO SOUTHWEST FLOW THROUGH EARLY NEXT WEEK. TEMPERATURES SHOULD
BE MODERATE OVER THE MAINLAND THROUGH THIS PERIOD WITH SOME RAIN AT
TIMES. NOT MUCH IS EXPECTED TO REACH SOUTH CENTRAL DURING THE FIRST
WAVE WEDNESDAY. HOWEVER...CLOUDY AND WET WILL PREVAIL AFTER THAT.
HOWEVER...THE SOUTHWEST SHOULD BE QUITE WET.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALE 155 165 171 172 179 180 185
         STORM 170
FIRE WEATHER...NONE

JN APR 09