Area Forecast Discussion
Issued by NWS Fairbanks, AK

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FXAK69 PAFG 011006
AFDAFG

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
206 AM AKDT WED JUL 1 2015

.DISCUSSION...
MODELS INITIALIZED WELL AND VERIFIED WELL AGAINST THE 00Z AND 06Z
ANALYSIS. MODELS HAVE FINALLY COME INTO GOOD AGREEMENT ON THE
LOCATION AND MAGNITUDE OF THE HEAVY RAIN EVENT OVER THE CENTRAL
AND SOUTHEASTERN INTERIOR AS WELL AS THE CENTRAL AND EASTERN
ALASKA RANGE NOW THAT THE EVENT HAS STARTED.

THE 00Z ECMWF HAS FINALLY COME INTO AGREEMENT WITH THE NAM12 AND
GFS MODELS IN DEVELOPING A HEAVY RAIN CORRIDOR ALONG A LINE AND 75
MILES EITHER SIDE FROM EAGLE SOUTHWEST TO DELTA JUNCTION TO DENALI
PARK. THIS IS SLIGHTLY WEST BY ABOUT 50 MILES AS COMPARED TO THE
RECENT NAM12 AND GFS SOLUTIONS BUT AROUND 100 MILES EAST OF THE
RECENT ECMWF SOLUTIONS. LATEST POSITION OF THE HEAVY RAIN CORRIDOR
NOW INCLUDES THE UPPER CHENA BASIN AND THE EASTERN PORTION OF ZONE
222. WILL NEED TO MONITOR THE UPPER CHENA BASIN FOR HEAVY RAIN AS
THE EVENT UNFOLDS AS CURRENT WATCHES AND ADVISORIES ARE CLUSTERED
TO THE EAST. LATEST MODEL RUNS STILL INDICATE BETWEEN 1 AND 3
INCHES OF RAIN FALLING THROUGH FRIDAY MORNING WITH HEAVIER
BULLSEYES ALONG THE CORRIDOR OUTLINED ABOVE. ONGOING FLOOD WATCH
FOR THE GOODPASTER RIVER LOOKS ON TRACK WITH HEAVIEST RAIN
FORECAST TO LINE UP WITH THE ENTIRE GOODPASTER BASIN. ONGOING
SMALL STREAM FLOOD ADVISORY ALSO LOOKS TO BE ON TRACK WITH
FORECASTED RAIN FALL AMOUNTS AND LOCATIONS. MAY NEED TO CONSIDER
ADDITIONAL AREAS TO THE WEST...CONTINUE TO MONITOR AS SITUATION
UNFOLDS.

A SHORTWAVE ALONG THE NORTHWEST COAST WILL CONTINUE TO MOVE SLOWLY
SOUTH AND EAST AND WILL BE LOCATED ALONG A BARROW TO KOTZEBUE
LINE BY THURSDAY AFTERNOON AND WILL BE THE FOCAL POINT FOR
SCATTERED RAIN SHOWERS. THE WESTERN INTERIOR CONTINUES TO BE WARM
RELATIVELY DRY AND SMOKEY WITH DENSE SMOKE STILL COVERING ZONE
221. EXPECT SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IN THESE
AREAS TODAY.

MODELS EXHIBIT INCREASING SPREAD IN THE MID TERM WITH STRENGTH AND
POSITION OF BUILDING RIDGE BUILDING FROM THE SOUTHEAST AND
MERGING WITH STRONG HIGH PRESSURE OVER SIBERIA. MODEL SPREAD
BECOMES LARGE BY EARLY NEXT WEEK WITH THE OPERATIONAL GFS AND
ECMWF BECOMING ESSENTIALLY 180 DEGREES OUT OF PHASE. MADE LITTLE
CHANGES TO LONG TERM FORECAST PACKAGE WITH ONLY SLIGHT DOWNWARD
NUDGES TO THE TEMPERATURES BASED IN LARGE PART ON ENSEMBLE
FORECASTS WHICH SEEMED PRUDENT WITH LARGE MODEL TO MODEL AS WELL
AS RUN TO RUN DIFFERENCES IN THE OPERATIONAL MODELS.


COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE

&&

.FIRE WEATHER...
ONLY A SMALL AREA OF MIN RH VALUES FORECASTED TO BE IN THE 30S
WHICH IS LOCATED ALONG THE SOUTHERN SLOPES OF THE BROOKS RANGE
AND NORTH OF THE YUKON RIVER THIS AFTERNOON. AS SURFACE LOW
DEEPENS IN THE WESTERN YUKON WEST WINDS OVER HIGHER TERRAIN AND
CHANNELED AREAS WILL INCREASE TO 15 TO 25 MPH HOWEVER MIN RH
VALUES ARE NOT EXPECTED TO MEET RED FLAG CRITERIA. IRONICALLY AN
INCREASING CONCERN FOR FIRE FIGHTING EFFORTS IN THE CENTRAL AND
EASTERN INTERIOR WHERE HEAVY RAIN IS EXPECTED OVER THE NEXT COUPLE
DAYS WILL BE INCREASING WATER LEVELS ALONG SMALL STEAMS AND RIVERS
AND TRAFFICABILITY ISSUES THAT HIGH RIVER AND STREAM FLOWS
PRESENT.

&&

.HYDROLOGY...
ONGOING ADVISORIES AND WATCHES LOOK TO BE ON TRACK WITH
ANTICIPATED HEAVY RAIN CORRIDOR WHERE 1 TO 3 INCHES AND LOCALLY
HEAVIER RAIN FALL IS EXPECTED. CONTINUE TO MONITOR FOR HEAVY RAIN
DEVELOPING JUST EAST OF FAIRBANKS TO INCLUDE THE UPPER CHENA
BASIN.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH FOR AKZ223-AKZ224.

DENSE SMOKE ADVISORY FOR AKZ221.

SMALL CRAFT ADVISORY FOR PKZ210-PKZ220-PKZ225-PKZ230.

GALE WARNING FOR PKZ225-PKZ230.
&&

$$

CCC JUL 15


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