461 
FXAK69 PAFG 031244
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
444 AM AKDT FRI SEP 3 2010

.DISCUSSION...
ALOFT...A TRANSITORY PATTERN EXPECTED DURING THE NEXT SEVERAL DAYS 
AS A SERIES OF RIDGES AND TROUGHS TRAVERSE THE AREA.  IN SUCH A 
PATTERN THERE ARE SOME MODEL TIMING AND DEPTH DIFFERENCES NOTED BUT 
THE BIG PICTURE LOOKS MUCH THE SAME INTO THE MIDDLE OF NEXT WEEK.  

SURFACE...A 1023 MB HIGH CENTER ABOUT 400 MILES NORTH OF DEMARCATION 
POINT LOOKS TO BE A STABLE FEATURE DURING THE NEXT FEW DAYS.  THE 
RIDGE IS EXPECTED TO CONTINUE TO BUILD SLOWLY TO THE NORTHEAST AND 
THE MODELS CONTINUE TO BE CONSISTENT THAT THE HIGH SHOULD END UP IN 
THE NEIGHBORHOOD OF 1030 MB ACROSS THE WESTERN CANADIAN ARCHIPELAGO 
BY 12Z MONDAY.   A 981 MB LOW ACROSS THE SOUTHERN ALEUTIANS WILL 
REMAIN WEST OF THE DATELINE THROUGH SUNDAY BUT PIECES OF ENERGY AND 
WEAKER SURFACE TROUGHS WILL PEEL OFF FROM THE MAIN LOW CENTER AND 
MOVE ACROSS THE EASTERN BERING SEA AND THE WESTERN MAINLAND. 

WEST COAST...A BRIEF REPRIEVE FROM THE STEADY RAIN TODAY ACROSS
Y-K DELTA AS SOME MID LEVEL RIDGING TRAVERSES THE AREA. THE DRIER
WEATHER WILL BE SHORT-LIVED AS THE RIDGE PUSHES EAST THIS EVENING
AND OPENS THE DOOR FOR ANOTHER GOOD SLUG OF MOISTURE AND A FRONTAL
BOUNDARY TO MOVE INTO THE AREA. THE MOISTURE WILL CONTINUE TO
STREAM NORTH ON SATURDAY AND MOST AREAS ALONG THE WEST COAST WILL
BE WET WITH PERIODS OF RAIN. THE WEATHER THEN BEGINS TO DRY OUT BY
LATE SUNDAY AND MORE SO SUNDAY NIGHT AS ANOTHER RIDGE BUILDS BACK
ACROSS THE AREA. THIS IS NOT THE END OF THE WET WEATHER THOU AS
YET A STRONG WAVE LOOKS TO RETURN THE WET WEATHER YET AGAIN ON
MONDAY. TEMPERATURES WILL CONTINUE TO REMAIN MILD ENOUGH TO
SUPPORT ALL RAIN DURING THE NEXT FEW DAYS.

NORTH SLOPE...NO END IN SIGHT FOR THE EASTERLY FLOW AS THE SURFACE 
HIGH CONTINUES TO BUILD.  THIS WILL CONTINUE TO PRODUCE AREAS OF 
STRATUS...FOG...AND DRIZZLE. SOME CLEARING IS POSSIBLE DURING THE
AFTERNOON...ESPECIALLY INLAND. THERE WILL LIKELY CONTINUE TO BE
A DIURNAL COMPONENT TO THE FOG WITH THE LOWEST VSBY FROM MIDNIGHT
THROUGH LATE MORNING EACH DAY. THE STRONGEST GRADIENT WILL REMAIN
ALONG THE BEAUFORT SEA COAST WHERE SMALL CRAFT ADVISORIES WILL
LIKELY CONTINUE THROUGH AT LEAST SUNDAY.

INTERIOR...TODAY LOOKS TO BE THE LAST DAY WITH ANY CONVECTION DURING 
THE SHORT TERM AS A WEAK THERMAL TROUGH REMAINS ACROSS THE EASTERN 
INTERIOR WITH MODEST LEVELS OF INSTABILITY. ANY LIGHTNING IS 
EXPECTED TO BE ISOLATED AT BEST AS HAS BEEN THE CASE THIS WEEK.  
MUCH OF THE CENTRAL INTERIOR LOOKS DRY TODAY WITH THE CHANCE OF SOME 
SHOWERS ACROSS THE WESTERN INTERIOR IN ASSOCIATION WITH THE OLD 
DECAYING FRONTAL BOUNDARY THAT PUSHED INTO THE WEST COAST 
YESTERDAY.  THE INTERIOR THEN LOOKS DRY TONIGHT INTO SATURDAY 
MORNING AS A TRANSIENT MID LEVEL RIDGE MOVES FROM WEST TO EAST ACROSS 
THE AREA.  AS THE RIDGE BEGINS TO PUSH EAST IT WILL INTRODUCE A 
RETURN TO MOIST SOUTHWEST FLOW WITH RAIN LIKELY BY AFTERNOON ACROSS 
THE FAR WESTERN INTERIOR.  SOME OF THIS RAIN WILL PUSH EAST SAT 
NIGHT AND SUNDAY.  IT THEN LOOKS LIKE MUCH OF THE INTERIOR DRIES OUT 
AGAIN ON MONDAY AS ANOTHER RIDGE BEGINS TO BUILD ACROSS THE AREA. 

MID-RANGE...THE 00Z RUN OF THE MODELS ARE IN BETTER AGREEMENT 
ALTHOUGH IT SHOULD BE NOTED THAT THE NCEP RMOPS CONTINUE TO INDICATE 
LOW RELATIVE MEASURES OF PREDICTABILITY DURING THE MEDIUM RANGE.  
THERE IS AT LEAST IN A GENERAL SENSE AGREEMENT THAT THE MAIN BERING 
SEA LOW PUSHES EAST NEXT WEEK AND INTO NORTHERN AK.  THIS LEADS TO A 
LOWER HEIGHT PATTERN THAT WILL LEAD TO NEAR OR PERHAPS SLIGHTLY 
BELOW AVERAGE TEMPS ALONG WITH SOME SHOWERS.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE

&&

.FIRE WEATHER...NONE. 

&&

.HYDROLOGY...THE FORTYMILE RIVER AT THE TAYLOR HIGHWAY BRIDGE HAS 
RISEN 5 FEET SINCE TUESDAY DUE TO RECENT RAINS...BUT WILL REMAIN
WELL WITHIN IT'S BANKS AND SHOULD BEGIN TO RECEDE LATER TODAY.
SMALL STREAMS AND CREEKS ARE PROBABLY RUNNING GOOD...BUT WITHIN
BANKFULL. 

THE ON AGAIN OFF AGAIN RAIN ACROSS WESTERN ALASKA WILL CONTINUE TO
KEEP STREAMS AND CREEKS RUNNING HIGH...BUT NO PROBLEMS ARE
FORESEEN ON ANY OF THE MAIN-STEM RIVERS. 

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR PKZ210-PKZ230-PKZ235-PKZ240-PKZ245.
&&

$$

CB SEP 10