Severe Thunderstorm Warning 1, NWS Fairbanks, AK

921 
WWAK59 PAFG 240429
SVSAFG

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE FAIRBANKS AK
828 PM AKDT MON JUN 23 2014

AKZ220-240438-
/O.EXP.PAFG.SV.W.0001.000000T0000Z-140624T0430Z/
YUKON FLATS AND SURROUNDING UPLANDS-
828 PM AKDT MON JUN 23 2014

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL YUKON FLATS AND
SURROUNDING UPLANDS WILL EXPIRE AT 830 PM AKDT...
                
THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.
THEREFORE THE WARNING WILL BE ALLOWED TO EXPIRE. HOWEVER SMALL HAIL
AND HEAVY RAIN ARE STILL POSSIBLE WITH THIS THUNDERSTORM.

LAT...LON 6580 14725 6578 14752 6595 14763 6599 14712
TIME...MOT...LOC 0418Z 171DEG 5KT 6584 14740 

$$

JB

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
1204 PM AKDT MON JUN 23 2014

.DISCUSSION...
UPPER AIR...
A WEAKENING UPPER LEVEL TROUGH EXTENDS FROM THE BARROW AREA
SOUTHWARD ACROSS THE WESTERN INTERIOR. THIS TROUGH WILL
TRANSITION INTO A COL AREA OVER THE WESTERN INTERIOR BY
TUE AS UPPER LEVEL RIDGING BUILDS OVER THE NORTHEAST INTERIOR
AND THE EASTERN BROOKS RANGE. 850 MB TEMPERATURES APPROACHING
+10C NEAR THE ALCAN BORDER IN THE NORTHEAST INTERIOR TODAY AND
TUE. THE WARMEST AIR AT 850 MB...TEMPERATURES AS HIGH AS +16C
TO +20C...WILL REMAIN OVER NORTHWEST CANADA.

CURRENT GFS/ECMWF ARE IN BETTER AGREEMENT TODAY ON KICKING AN
UPPER LOW NORTHWARD OUT OF THE GULF OF ALASKA INTO THE EASTERN
ALASKA INTERIOR AS ANOTHER UPPER LOW MOVES EASTWARD INTO THE GULF
OF ALASKA. BY 00Z FRI...ECMWF AND CANADA MODELS PUT THE CENTER
NEAR THE ALCAN BORDER NORTH OF NORTHWAY...GFS PUTS THE CENTER
NEAR THE EASTERN BORDER OF THE MIDDLE TANANA VALLEY. AS WAS THE
CASE YESTERDAY...NAM KEEPS THE LOW CENTER FARTHER TO THE
EAST...OVER THE SOUTHERN YUKON TERRITORY NEAR MAYO BY THU
AFTERNOON. BY FRI AFTERNOON...GFS/ECMWF MODELS TAKE THE LOW
NORTHWESTWARD INTO THE NORTHWEST ALASKA INTERIOR...WITH THE NAM
POSITION A BIT FARTHER TO THE SOUTHEAST. GFS/ECMWF CONSENSUS IS
PREFERRED FOR THIS FORECAST CYCLE ON THE HANDLING OF THIS UPCOMING
EVENT...GFS/ECMWF MOVING THE SIGNIFICANT RAIN WESTWARD FASTER THAN
THE NAM. IN THE SHORTER TERM...GFS/NAM BLEND LOOKS APPROPRIATE.
FOR THE MAJOR RAIN EVENT...GFS/ECMWF BLEND WITH THE GFS WEIGHTED
MORE.

SURFACE...
A WEAK SEA LEVEL PRESSURE GRADIENT IS OVER THE INTERIOR TODAY.
A WEAK THERMAL TROUGH IS EXPECTED TO DEVELOP ACROSS THE NORTHERN
INTERIOR AND BROOKS RANGE TUE...SHIFTING SLOWLY SOUTHWARD INTO
THE INTERIOR WED. AS THE UPPER LOW MOVES NORTHWARD THEN
NORTHWESTWARD ACROSS THE INTERIOR...A SURFACE LOW IS EXPECTED TO
DEVELOP WED EVENING AND DEEPEN SOME LATER WED NIGHT AND THU.
THIS WILL SET UP AN INCREASED SEA LEVEL PRESSURE GRADIENT AND
INCREASED WIND SPEEDS ACROSS THE BROOKS RANGE..ARCTIC SLOPE...
AND THE ARCTIC COAST.

GOES VIS LOOP SHOWS EXTENSIVE STRATUS OVER NORTON SOUND AND
COASTLINE AREAS FROM DALL POINT TO WALES. THESE AREAS LIKELY TO
REMAIN CLOUDY AT LEAST THRU TUE WITH ONSHORE FLOW. STRATUS ALSO
COVERS MUCH OF KOTZEBUE SOUND AND THE CHUKCHI SEA WEST AND SOUTH
OF POINT HOPE.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE

&&

.FIRE WEATHER...
WARM AND DRY OVER THE EASTERN INTERIOR TODAY WITH MIN RH 20-35
PERCENT IN MOST AREAS. MIN RH VALUES TUE MAY BE SLIGHTLY HIGHER.
HIGHER HUMIDITIES AND GOOD LIKELIHOOD OF WETTING RAINS OVER THE
INTERIOR WED AND THU AS RAIN DEVELOPS IN THE EASTERN INTERIOR AND
SPREADS NORTH AND WEST. THUNDERSTORM ACTIVITY THIS AFTERNOON AND
EVENING IS EXPECTED TO BE MAINLY OVER THE SOUTHERN AND EASTERN
INTERIOR AND ALASKA RANGE...A FEW THUNDERSTORMS POSSIBLE IN
PARTS OF THE WESTERN INTERIOR WITH THE DECAYING UPPER TROUGH. FOR
TUE...THUNDERSTORM ACTIVITY MOST LIKELY OVER THE WESTERN AND
CENTRAL INTERIOR...WESTERN ALASKA RANGE...AND CENTRAL
BROOKS RANGE. FOR WED...THUNDERSTORM ACTIVITY IS EXPECTED TO BE
OVER THE WESTERN INTERIOR. THUNDERSTORMS WILL BE MOSTLY WET.

&&

.HYDROLOGY...
ANOTHER SIGNIFICANT RAIN EVENT IS LIKELY OVER THE INTERIOR WITH
THE UPPER LOW MOVING NORTHWARD THEN NORTHWESTWARD...ALONG WITH
THE DEVELOPMENT OF THE SURFACE LOW. CURRENT GFS AND ECMWF
INDICATE THE HEAVIEST RAINFALL AMOUNTS WILL BE OVER THE ALASKA
RANGE AND ADJOINING AREAS TO THE NORTH. 48 HOUR RAINFALL TOTALS
12Z WED THROUGH 12Z FRI COULD REACH OR EXCEED 2 INCHES IN PARTS OF
THE ALASKA RANGE...1 TO 2 INCHES IN ADJOINING AREAS NORTH OF THE
ALASKA RANGE...AND 0.25 TO 1 INCH OVER REMAINING AREAS OF THE
CENTRAL AND EASTERN INTERIOR. RAIN WILL SPREAD INTO THE NORTHWEST
INTERIOR THU NIGHT AND FRI. SMALL STREAMS COULD RISE TO NEAR OR
ABOVE BANKFULL IN AREAS WHERE THE HEAVIEST RAINFALL AMOUNTS
OCCUR....WITH EVENTUAL SIGNIFICANT RISES IN THE LEVELS ON LARGER
RIVERS. LOCAL AMOUNTS OF 0.25 INCH OR MORE POSSIBLE IN SHOWERS
THROUGH TUE TONIGHT...ESPECIALLY OVER THE WESTERN INTERIOR AND
ALASKA RANGE. THE FLOOD ADVISORY FOR THE CHENA RIVER IN NORTH
POLE WAS CANCELLED THIS MORNING.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

RF JUN 14