Small Craft Advisory 547, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM ADT SAT JUL 9 2005

.DISCUSSION...
CURRENTLY...GOOD 850 THERMAL RIDGE FROM THE KUSKOKWIM VALLEY EAST.
ENOUGH MOISTURE IN THE AIR FOR SCATTERED SHOWERS AND THUNDERSTORMS
NORTH OF ABOUT AN ANCHORAGE TO ILIAMNA LINE TAPERING OFF TO NOTHING A
BIT SOUTH OF THAT LINE. THUNDERSTORMS ALREADY POPPING ALONG THE
ALASKA RANGE AND TALKEETNA MOUNTAINS. THIS WILL BE THE AREAS WITH THE
MOST ACTIVITY. WEAK RIDGE OVER THE ALEUTIAN CHAIN DUE TO LOW WITH
PLENTY OF STRATUS ALONG THE COAST OF WESTERN ALASKA THROUGH THE
ALEUTIAN CHAIN. STRATUS TO STAY OVER THE COASTAL AREAS BUT BURN OFF
THIS AFTERNOON ON THE MAINLAND ONLY TO REDEVELOP IN MOST PLACES
OVERNIGHT.

UPPER LEVEL LOW NEAR 73N 180 PUSHING A SHORT WAVE TROUGH ONTO THE
WEST COAST OF ALASKA TODAY. THE LOW WILL MOVE EAST TO THE NORTHERN
ALASKA COAST MONDAY AFTERNOON AND INTO EXTREME NORTHERN CANADA
TUESDAY. THE ASSOCIATED TROUGH WILL PASS THROUGH THE CENTRAL PORTION
OF THE STATE TONIGHT AND TOMORROW STABILIZING THE AIR MASS AS IT
PASSES. THIS IS DUE TO THE COOLER AIR BEHIND THE FRONT. AIR MASS
STABILIZES OVER WESTERN ALASKA THIS EVENING WITH THE PASSAGE OF THIS
FEATURE THEN SOUTH CENTRAL BY TOMORROW EVENING. THUNDERSTORM ACTIVITY
OVER SOUTH CENTRAL ALASKA WILL BE ISOLATED TO SCATTERED TOMORROW AS
THE FRONT PASSES WITH THE MAIN PRECIPITATION MAKER BEING SCATTERED
SHOWERS OVER MUCH OF THE AREA NORTH OF KENAI PENINSULA.

A LOW PRESSURE SYSTEM MOVES INTO THE WESTERN ALEUTIANS SUNDAY
AFTERNOON AND RIDES ALONG THE CHAIN INTO BRISTOL BAY BY TUESDAY.
MODERATE WINDS AND PRECIPITATION TO ACCOMPANY THIS LOW ALONG THE
CHAIN. SURFACE PRESSURE REFLECTION OF THIS LOW IS RATHER WEAK
HOWEVER. OVER SOUTH CENTRAL ALASKA...THE RESULT WILL BE A MORE MOIST
SOUTHERLY FLOW BY TUESDAY AFTERNOON FOR A CHANCE OF SHOWERS AND
THUNDERSTORMS FROM THE TALKEETNA AND CHUGACH MOUNTAINS WESTWARD.

ANOTHER LOW MOVES INTO THE WESTERN ALEUTIAN CHAIN TUESDAY WITH
MODERATE WINDS AND PRECIPITATION ONCE AGAIN. THIS LOW WILL TRACK
SLOWLY EAST TO THE EASTERN ALEUTIANS BY THURSDAY. IN ADDITION...THE
LOW IN THE BRISTOL BAY AREA SLIDES EAST ACROSS THE GULF AS AN OPEN
WAVE. HOWEVER...THE UPPER LEVEL FLOW REMAINS CONDUCIVE TO A MOIST
SOUTHERLY FLOW OVER SOUTH CENTRAL ALASKA. THIS SOUTHERLY FLOW DOES
NOT ALLOW A STRONG 850 THERMAL RIDGE TO DEVELOP OVER SOUTH CENTRAL
AND SOUTHWEST ALASKA. THEREFORE...ANY ACTIVITY OVER THE MAINLAND WILL
MOST LIKELY CONFINED TO THE HIGHER TERRAIN AND ALONG THE GULF COAST.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...NONE
FIRE WEATHER...NONE

JN JUL 05