Flash Flood Warning 4, NWS Fairbanks, AK

236 
WGAK79 PAFG 030726
FFSAFG

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE FAIRBANKS AK
1126 PM AKDT FRI JUL 2 2010

AKZ221-030735-
/O.EXP.PAFG.FF.W.0004.000000T0000Z-100703T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CENTRAL INTERIOR AK-
1126 PM AKDT FRI JUL 2 2010

...THE FLASH FLOOD WARNING WILL EXPIRE AT 1130 PM AKDT FOR THE ELLIOTT
HIGHWAY FROM MILE POSTS 85 TO 70 ...

SHOWERS ENDED SEVERAL HOURS AGO AND NO NEW RAIN IS EXPECTED OVERNIGHT

LAT...LON 6545 14888 6542 14878 6533 14898 6536 14908

$$

RT

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
1153 AM AKDT FRI JUL 2 2010

.DISCUSSION...
MODELS IN DECENT AGREEMENT THROUGH ABOUT 60 HOURS. THERMAL TROUGH
EXTENDS FROM ABOUT EAGLE TO AMBLER BUT WILL ROTATE SOUTHWARD OVER
THE NEXT 2 DAYS AND BE NEAR CHICKEN TO FAIRBANKS TO BUCKLAND BY
ABOUT LATE SAT NIGHT.

WEAK UPPER LEVEL RIDGING ACROSS THE ARCTIC COAST WILL PERSIST
THROUGH SAT EVENING. THERMAL LOW WILL DEEPEN OVER THE SOUTHEASTERN
INTERIOR THROUGH SAT EVENING AND THEN WEAKEN SLIGHTLY AND MOVE
NORTH TO NEAR FORT YUKON WHILE ANOTHER THERMAL LOW DEVELOPS NEAR
HUSLIA BY LATE SUN EVENING.

MUCH COOLER TEMPERATURES WILL BEGIN PUSHING SOUTHWARD FROM THE
HIGH ARCTIC TONIGHT AND WILL PERSIST THROUGH THE FIRST PART OF
NEXT WEEK. THIS WILL TRANSLATE TO MUCH COOLER TEMPERATURES ACROSS
THE ARCTIC PLAIN AND ZONE 208.

SURFACE LOWS THAT ARE MOVING EAST FROM THE ALEUTIANS WILL BE KEPT
FROM MAKING MUCH FURTHER EASTWARD PROGRESS THAN THE GULF OF ALASKA
BY THE UPPER LEVEL RIDGE OVER SOUTHEAST ALASKA. THIS WILL GENERATE
SOUTHEAST FLOW OVER MUCH OF EASTERN AND CENTRAL ALASKA FOR THE
NEXT 48 HOURS OR SO. THIS WILL KEEP A MORE MOIST PATTERN OVER THE
CENTRAL AND EASTERN PORTION OF THE STATE.

LIGHTNING MAP ON THURSDAY SHOWED THAT A MAJORITY OF THE
CONVECTION FOLLOWED THE THETA E RIDGE QUITE WELL AND DO NOT
FORESEE A SIGNIFICANT CHANGE FROM THAT PHILOSOPHY FOR THE
REMAINDER OF TODAY AND THIS EVENING. THIS TRANSLATES INTO MOST OF
THE CONVECTION DEVELOPMENT BEING NORTH OF A LINE FROM ABOUT
NORTHWAY TO FAIRBANKS TO HUSLIA. THIS THETA E RIDGE WILL SHIFT
SOUTHWARD ON SATURDAY WITH THE AXIS OF THE THETA E RIDGE LYING
FROM ABOUT CHICKEN TO FAIRBANKS TO BETTLES WITH ANOTHER ARM
EXTENDING FROM BETTLES TO ARCTIC VILLAGE.

ARCTIC COAST...WITH HIGH PRESSURE INFLUENCE OVER THE ARCTIC
COAST...THIS IS CREATING ONSHORE FLOW AND WILL LIKELY CONTINUE
WELL INTO THE WEEKEND...EXPECT DENSE FOG AND LOW STRATUS. A
RELATIVELY DECENT COLD FRONT WILL APPROACH THE ARCTIC COAST FROM
THE WEST BEGINNING ON ABOUT SUNDAY AND THEN PUSH EASTWARD. THIS
WILL DROP THE TEMPERATURES ON THE ARCTIC COASTAL PLAIN. IT MAY
DROP THE TEMPERATURES ACROSS THE COASTAL AREAS A COUPLE OF DEGREES
AS WELL.

WEST COAST...WEAK LOW PRESSURE IN THE BERING SEA WILL MOVE
SOUTHWARD WHILE HIGH PRESSURE BUILDS IN OVER THE AREA FROM THE
HIGH ARCTIC BEGINNING LATER SATURDAY AND CONTINUE THROUGH MID
WEEK. TEMPERATURES ALOFT WILL BEGIN TO COOL SLIGHTLY BEGINNING
SUNDAY WITH THE ADVANCE OF THE COLD FRONT FROM THE HIGH
ARCTIC. NORTH WINDS WILL DEVELOP OVER THE WEST COAST ON SUNDAY AND
THE PRESSURE GRADIENT WILL TIGHTEN IN THE BERING STRAIT AND THE
WESTERN SEWARD PENINSULA. THIS SCENARIO COULD CAUSE SOME COASTAL
PROBLEMS FOR THE NORTHERN SEWARD PENINSULA...NAMELY SHISHMAREF
SINCE THE WINDS LOOK TO BE AROUND 30 KT OR SO OVER A PERIOD OF
AT LEAST 24 HOURS BEGINNING LATER SUNDAY.

INTERIOR...THERMAL TROUGH AND THETA E RIDGE ARE THE INDICATORS OF
BEST CONVECTION DEVELOPMENT CURRENTLY. GIVEN THE CURRENT LOW FLOW
REGIME OVER THE CENTRAL INTERIOR...RAINFALL OVER PARTS OF THE
INTERIOR ARE RELATIVELY HEAVY DUE TO NO ADVECTION OF THE CELLS. THE
THERMAL TROUGH WILL SINK SOUTHWARD OVER THE INTERIOR AND FORM THE
AXIS FROM ABOUT CHICKEN TO FAIRBANKS TO HUSLIA ON SATURDAY. THIS
SHOULD BE THE AREA WITH THE MOST FAVORABLE CONDITIONS FOR
CONVECTION DEVELOPMENT ON SATURDAY.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE

&&

.FIRE WEATHER...DUE TO EXCESSIVE LIGHTNING STRIKES...NUMEROUS NEW
FIRES ARE BEING INITIATED ALTHOUGH THE THUNDERSTORMS ARE WET IN
NATURE. RH VALUES WILL CONTINUE TO BE AROUND 40 PERCENT FOR
MINIMUMS OVER THE INTERIOR.

&&

.HYDROLOGY...FLASH FLOOD WARNING IN EFFECT FOR AREAS ALONG THE
ELLIOT HIGHWAY NEAR LIVENGOOD. EXPECT CONTINUED HEAVY RAINFALL
UNTIL UPPER LEVEL FLOW INCREASES.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WARNING...ZONES 220 AND 222
&&

CF JUL 10