Storm Warning 136, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM ADT SUN SEP 17 2006

.DISCUSSION...
ALL MODELS IN GOOD AGREEMENT TODAY EXCEPT UKMET A LITTLE OUT OF LINE.
THE SLOWER PROGRESSION OF THE NORTH PACIFIC LOW INTO BRISTOL BAY HAS
BEEN THE PREFERRED SOLUTION AND ALL MODELS AGREES OUTSIDE OF THE
UKMET. GFS HAS INITIALIZED BETTER THAN THE NAM THIS MORNING. MODELS
COME BACK TOGETHER EARLY TONIGHT.

UPPER LEVELS...CLOSED LOW OVER THE GULF TO BE PUSHED EAST AS A LOW
DEVELOPS OVER THE EASTERN ALEUTIAN CHAIN THIS EVENING. THE LOW
DEVELOPING IN THE ALEUTIANS IS FROM A SHORT WAVE TROUGH MOVING OUT OF
THE BERING MERGING WITH A VIGOROUS SHORT WAVE MOVING OUT OF THE NORTH
PACIFIC. THE NORTH PACIFIC LOW IS RIDING A JET AXIS WITH SPEEDS
AROUND 100 KTS. THE LOW WILL DEEPEN OVER THE CENTRAL ALEUTIANS
TONIGHT INTO TOMORROW WITH GREAT JET AND THERMAL SUPPORT. THE JET
LOSES JET SUPPORT AND THE THERMAL SUPPORT IS MODERATED MONDAY NIGHT.
THE LOW WILL THEN BEGIN TO FILL OVER BRISTOL BAY TUESDAY. A STRONG
JET REMAINS TO THE SOUTH WITH A FEW LOWS RIDING TO THE PANHANDLE. IN
THE MEANTIME...A SHORT WAVE TROUGH MOVES SOUTH THROUGH THE WESTERN
BERING TUESDAY AND ROUNDS THE TROUGH OVER THE CENTRAL ALEUTIANS
WEDNESDAY. ENOUGH JET SUPPORT WITH THIS WAVE TO HELP PULL THE LOW IN
BRISTOL BAY EAST TO THE GULF THURSDAY INTO FRIDAY. HELPING THIS
PROGRESSION IS A RIDGE PUSHING ACROSS THE WESTERN BERING DUE TO A
STRONG LOW MOVING OUT OF MONGOLIA WEDNESDAY TO THE KAMCHATKA
PENINSULA FRIDAY.

SURFACE WEST OF THE ALASKA RANGE...A 992 MB LOW SOUTHWEST OF THE
CENTRAL ALEUTIAN ISLANDS TO MOVE TOWARD DUTCH TONIGHT AND TO COLD BAY
TOMORROW. STRONG BAROCLINIC NATURE TO THE LOW CENTER. THIS WILL
LIKELY PRODUCE VERY STRONG WINDS NEAR THE LOW. THEREFORE...HAVE GONE
WITH HIGH WIND WARNING FOR ZONE 185 AS THE LOW CENTER PULLS EAST OF
DUTCH HARBOR LATER THIS EVENING. STRONG WINDS WILL ENCIRCLE THE LOW
AS IT WORKS TO BRISTOL BAY TUESDAY MORNING. THIS IS ESPECIALLY TRUE
ON THE BACK SIDE OF THE LOW IN COLD AIR ADVECTION. THE LOW WILL MOVE
INTO BRISTOL BAY MONDAY NIGHT. THE LOW WILL BE STATIONARY INTO
WEDNESDAY AND WEAKEN AS THE JET SUPPORT LEAVES THE LOW. AN ASSOCIATED
FRONT TO MOVE INTO THE GULF MONDAY AFTERNOON AND INLAND TUESDAY
NIGHT. A BROAD AREA OF LOW PRESSURE WILL THEN BE OVER THE MAINLAND
WITH A WEAKER LOW CENTER OVER THE CENTRAL ALEUTIANS WEDNESDAY. THIS
AREA WILL SLOWLY MOVE EAST THROUGH FRIDAY AS HIGH PRESSURE BUILDS
FROM THE WEST. THE PRESSURE GRADIENT THAT RESULTS FROM THIS SCENARIO
WILL KEEP MODERATE NORTHERLY WINDS OVER THE BERING THAT WILL SLIDE
SLOWLY EAST. IN ADDITION...COLD AIR WILL CONTINUE TO FILTER INTO THE
BERING SEA AND TO WESTERN ALASKA THURSDAY AND FRIDAY. EVENTUALLY A
LOW WILL WORK TO THE KAMCHATKA PENINSULA FRIDAY WITH A STRONG FRONT
ACROSS THE WESTERN ALEUTIANS.

SURFACE EAST OF THE ALASKA RANGE...A LOW OVER THE SOUTHERN GULF WITH
PLENTY OF MOISTURE OVER SOUTH CENTRAL FROM WEAK UPPER LOW IN WESTERN
GULF. THE UPPER LEVEL LOW TO LIFT NORTH ALONG THE ALASKA RANGE WITH
SOME SHOWERS OVERNIGHT THROUGH THE SUSITNA VALLEY AND KENAI
PENINSULA. THIS FEATURE WILL BE OUT OF THE AREA BY TOMORROW. THE LOW
IN THE SOUTHERN GULF TO BE SOUTH OF THE QUEEN CHARLOTTE ISLANDS
TOMORROW AFTERNOON WITH A RIDGE OVER THE GULF AND EASTERN INTERIOR.
AT THIS TIME A FRONT APPROACHES THAT IS ASSOCIATED WITH AN ALEUTIAN
LOW. WINDS AND PRECIPITATION TO PICK UP IN THE WESTERN GULF MONDAY
AFTERNOON AND EVENING. WINDS WILL PICK UP OVER THE ENTIRE GULF
OVERNIGHT MONDAY WITH PRECIPITATION SPREADING TO THE KENAI PENINSULA.
THE FRONT WILL BE ON THE NORTHERN GULF COAST TUESDAY WITH
PRECIPITATION MAINLY LIMITED TO COASTAL AREAS AND UPSLOPE AREAS IN
THE SUSITNA VALLEY. WITH THE ONSET OF THE FRONT TOMORROW NIGHT AND
TUESDAY...A GOOD PRESSURE GRADIENT DEVELOPS ALONG THE NORTHERN GULF
COAST. WOULD EXPECT STRONG WINDS ALONG THE COAST VIA A BARRIER JET.
IN ADDITION...TURNAGAIN ARM WINDS AND OTHER SOUTHEAST TO NORTHWEST
ORIENTED GAPS TO OBSERVE STRONG WINDS. THIS PATTERN TO EXIST ROUGHLY
INTO WEDNESDAY BEFORE A PIECE OF THE LOW LIFTS THROUGH SOUTH CENTRAL
WEDNESDAY AFTERNOON AND EVENING BRINGING PRECIPITATION TO INLAND
LOCATIONS. THIS WILL ALSO LIFT THE MAIN LOW OVER BRISTOL BAY INLAND
TOWARD THE KUSKOKWIM VALLEY. WINDS WILL REMAIN MODERATE FROM THE
SOUTHWEST OVER THE GULF BEHIND THIS FEATURE. AN AREA OF BROAD LOW
PRESSURE THEN PREVAILS OVER SOUTH CENTRAL THURSDAY INTO FRIDAY WITH
SCATTERED PRECIPITATION AND LIGHTER WINDS.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WATCH ZONE 185
MARINE...STORM 170
         GALE 155 160 165 171 172 AND 179
FIRE WEATHER...NONE

JN SEP 06