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NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
126 AM AKDT SUN JUL 5 2015

.DISCUSSION...

MODELS...INITIALIZED WELL AGAINST THE 06Z SURFACE ANALYSIS AND
THEY ARE CLUSTERED WELL IN THE FIRST 84 HOURS OF THE MODEL RUN.
SOME MAJOR DIFFERENCES BEYOND THAT IN THE HANDLING OF A LOW OVER
THE BEAUFORT SEA AND WHETHER OR NOT RIDGING BUILDS BACK IN OVER
THE EASTERN INTERIOR. THEY HANDLE THE WEAK SHORTWAVE OVER THE
SOUTHWEST SIMILAR TODAY...BUT THE NEXT SHORTWAVE ON MONDAY NIGHT
AND TUESDAY IS NOT GETTING THE SAME TREATMENT. WITH SOUTHWEST FLOW
EXPECT THERE TO BE SOME SHADOWING OUT OF THE PRECIPITATION. THE
GFS AND ECMWF SHOW NONE...SO WILL LEAN MORE ON THE WAY THE NAM IS
HANDLING IT FOR NOW.

ALOFT...AT 500 HPA...RIDGE OVER THE EASTERN HALF OF THE STATE WITH
A 577 DAM HIGH OVER WAINWRIGHT AND A 590 DAM HIGH OVER THE
NORTHWEST PACIFIC WILL BUILD A BIT TO EXTEND WEST OVER THE MIDDLE
YUKON VALLEY TODAY AS THE 577 DAM CENTER MERGES INTO THE RIDGE.
THE RIDGE WILL SLIP A LITTLE TO THE EAST ON MONDAY AS 2 LOWS OVER
THE CENTRAL BERING SEA MERGE INTO A 531 DAM LOW AND SPIN A
SHORTWAVE OVER BRISTOL BAY MONDAY EVENING...THEN FROM THE LOW TO
OVER CAPE ROMANZOF TO TALKEETNA TO NORTHWAY BY TUESDAY
MORNING...AND FROM THE LOW TO GAMBELL TO OLD CROW BY LATE
TUESDAY. AT 850 HPA...TEMPERATURES WILL CONTINUE TO RISE ANOTHER 3
TO 6 DEGREES CELSIUS OVER MOST OF THE AREA TODAY AS THE RIDGE
BUILDS A BIT. ANOTHER SURGE IN WARM AIR WITH THE SHORTWAVE ON
MONDAY NIGHT AND TUESDAY WILL PUSH MOST OF THE FORECAST AREA ABOVE
15 DEGREES CELSIUS...THE EXCEPTION WILL BE THE LOWER YUKON DELTA
AND NORTON SOUND REGION WHERE TEMPERATURES WILL BE IN THE 3 TO 10
CELSIUS RANGE.

SURFACE...THERMAL TROUGH ACROSS THE INTERIOR FROM GALENA TO DAWSON
YUKON THIS MORNING WILL SHIFT A LITTLE NORTH OVER THE CENTRAL YUKON
RIVER AND FLATS THROUGH THE DAY AS THE SURFACE RIDGE SURGES
NORTHWEST OVER THE MIDDLE YUKON RIVER VALLEY. WEATHER FRONT
APPROACHING FROM THE SOUTHWEST MONDAY WILL BE OVER THE ALASKA
RANGE MONDAY EVENING AND MOVE ACROSS THE INTERIOR TO BE OVER THE
ARCTIC COAST LATE TUESDAY EVENING. THE SURFACE RIDGE WILL BUILD
BACK OVER MOST OF THE FORECAST AREA BEHIND THE FRONT. SOME GAP
WINDS IN THE ALASKA RANGE THIS MORNING WILL LAY DOWN BY LATE
MORNING...BUT STILL EXPECT SOME GUSTY WINDS TO AROUND 30 MPH. THE
FRONT ON MONDAY NIGHT WILL BRING ANOTHER ROUND OF GAP WINDS TO
THE RANGE...BUT DO NOT EXPECT THEM TO REACH 50 MPH...AND THEY WILL
TAPER DOWN BY AROUND NOON ON TUESDAY TO GUSTING TO AROUND 30 MPH.

SATELLITE...SPORT MICROPHYSICS MODIS AT 04/0655Z SHOWING THE
CLEARLY DEFINED CLOUD SHIELD ASSOCIATED WITH THE LOW IN THE BERING
SEA BUTTING UP AGAINST THE RIDGE. ASIDE FROM THAT PRETTY QUIET
ACROSS THE REGION WITH NO STRATUS OR FOG DETECTED NEAR ANY OF THE
COASTAL AREAS.

ARCTIC COAST AND BROOKS RANGE...VERY NICE DAY AHEAD ACROSS THE
ARCTIC. MOSTLY SUNNY CONDITIONS WITH WARMING TEMPERATURES. AS
MENTIONED ABOVE NO STRATUS TO CAUSE ANY HAVOC IN THE AREA. WEAK
SURFACE HIGH OVER THE EASTERN ARCTIC COAST DRIFTS OFF INTO CANADA
AND EAST TO SOUTHEAST...OFFSHORE IN MOST AREAS...FLOW THROUGH AT
LEAST MONDAY. A WEAK LEE SIDE TROUGH DEVELOPS MONDAY. SOME
INCREASED CLOUDS OVER THE NORTHWEST COAST ON TUESDAY AS A DECAYING
FRONT MOVES OVER THE AREA. HIGHS TODAY AND MONDAY IN THE 60S ON
THE COAST WITH INLAND TEMPERATURES REACHING THE 70S TO MID 80S.

WEST COAST AND WESTERN INTERIOR...WARMER AND DRIER OVER THE MIDDLE
YUKON...KOBUK...AND NOATAK VALLEYS TODAY. WEATHER FRONT MOVES TO
THE SOUTHWEST COAST TONIGHT AND WILL SPREAD SHOWERS OVER THE LOWER
YUKON DELTA BY MONDAY MORNING...AND TO THE MIDDLE YUKON AND MOST
OF THE SEWARD PENINSULA BY LATE MONDAY EVENING. DO NOT EXPECT MUCH
FOR THUNDERSTORM ACTIVITY BUT WOULD NOT BE SURPRISED TO GET SOME
EMBEDDED AS THERE ARE SOME NEGATIVE LIFTED INDICES SHOWING UP IN
THE MIDDLE YUKON AND UPPER KUSKOKWIM AREAS. WINDS WILL BE EAST TO
SOUTHEAST ACROSS THE AREA IN ADVANCE OF THE FRONT...THEN TURN TO
SOUTHWEST IN THE INTERIOR AREAS AND SOUTHEAST ALONG THE COAST.
COASTAL WINDS WILL KICK UP A BIT TO 10 TO 20 MPH FOR MOST
AREAS...WITH 15 TO 30 MPH WINDS IN THE BERING STRAIT AND ON ST
LAWRENCE ISLAND.

CENTRAL AND EASTERN INTERIOR...VERY WARM AND DRY TODAY AND MONDAY.
NOT MUCH CHANCE FOR SHOWERS WITH A PRETTY GOOD CAP ALOFT AND OTHER
CONVECTIVE INDICES ARE LESS THAN IMPRESSIVE. SOME GUSTY WINDS NEAR
THE RANGE THIS MORNING WITH GAP WINDS...WINDS WILL CONTINUE TO BE
GUSTY AROUND THE THERMAL TROUGH...TO AROUND 25 MPH. MOST AREAS
WILL SEE WINDS IN THE 5 TO 15 MPH RANGE DURING THE AFTERNOON AND
EVENING HOURS. WIND DIRECTION WILL DEPEND ON WHICH SIDE OF THE
THERMAL TROUGH YOU ARE ON...SO AROUND FAIRBANKS EXPECT SOUTHWEST
DURING THE DAY AND THE NORMAL LIGHT NORTHEAST DIURNAL WINDS
TONIGHT. ANOTHER ROUND OF GAP WINDS NEAR THE ALASKA RANGE ON
MONDAY NIGHT...DOES NOT LOOK LIKE THEY WILL BE STRONGER THAN 50
MPH RIGHT NOW...WILL HAVE THE NEXT SHIFT LOOK AT IT. TOUGH CALL ON
SHOWERS MONDAY NIGHT AND TUESDAY IN THE FAIRBANKS AREA SINCE SOME
OF IT WILL BE SHADOWED OUT BY THE ALASKA RANGE...THEN REFORM TO
THE NORTH OF TOWN. IT WILL ALL DEPEND ON THE FLOW DIRECTION MORE
SOUTH...NOT MUCH FOR SHOWERS...MORE WEST THEN MUCH BETTER CHANCE
FOR SHOWERS.

EXTENDED FORECAST DAYS 5 TO 8...LOW OVER THE BERING SEA IS
PERSISTENT AND RIDGING BUILDS BACK OVER THE EASTERN INTERIOR...SO
LOOKING FOR MORE OF WHAT WE HAVE NOW...WHICH IS A FEW DAYS OF
WARM THEN A DAY OF SHOWERS. CONVECTIVE INDICES LOOK GOOD IN THE
EXTENDED PERIODS OF MORE THUNDERSTORM ACTIVITY...BUT THIS IS QUITE
A WAS OUT IN THE FORECAST CYCLE TO MAKE THAT CALL.

&&

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE.

&&

.FIRE WEATHER...CONTINUED DRYING WITH THERMAL TROUGH ACROSS THE
INTERIOR. RELATIVE HUMIDITY VALUES WILL FALL BELOW 30 PERCENT OVER
MOST OF THE WESTERN...CENTRAL...AND EASTERN INTERIOR TODAY. SOME
GUSTY WINDS TO AROUND 25 MPH INTO THE THERMAL TROUGH WILL BRING
NEAR RED FLAG CONDITIONS TO THE EASTERN INTERIOR ALONG THE ALASKA
RANGE LATE THIS AFTERNOON BUT FUELS REMAIN A BIT TOO WET FOR
SIGNIFICANT BURNING. THAT COULD CHANGE MONDAY...SO WILL BE TAKING
A HARD LOOK AT FUEL CONDITIONS LATER TODAY.

&&

.HYDROLOGY...RIVERS CONTINUE TO FALL IN THE INTERIOR AFTER LAST
WEEKS RAINS WITH MOST OF THEM LEVELING BACK TO NORMAL FLOW BY
MONDAY MORNING.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

SMALL CRAFT ADVISORY FOR PKZ210.

&&

$$

SDB JUL 15

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