Wildfire in Alaska, August 3 to 16, 2009

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
440 AM AKDT MON AUG 3 2009

.DISCUSSION...
IF NOTHING ELSE THE WEATHER PATTERN HAS BEEN CONSISTENT MID-LATE
SUMMER THIS YEAR WITH WELL ABOVE AVERAGE TEMPERATURES AND BELOW
AVERAGE PRECIPITATION ACROSS THE INTERIOR. THE UPPER RIDGE THAT
HAS BEEN SUCH A PERMANENT AND TENACIOUS FEATURE SINCE LATE JUNE
REBUILDS WITH VENGEANCE ACROSS THE INTERIOR EARLY THIS WEEK. THE
UPPER LOW NEAR 170W RELOADS AND DEEPENS THROUGH THURSDAY. LATE IN
THE WEEK AND INTO NEXT WEEKEND THERE IS SOME GENERAL AGREEMENT
THAT THE LOW SLIDES EAST AND WEAKENS. A DEEP UPPER LOW IN THE
SIBERIAN SEA SLICES A PATH ACROSS THE HIGH ARCTIC THIS WEEK AND
ENDS UP ACROSS THE WESTERN CANADIAN ARCHIPELAGO BY WEEKS END.

INTERIOR...THE UPPER RIDGE CENTERED NEAR 125W THAT IS WHAT REMAINS
OF LAST WEEKS MONSTER RIDGE REBUILDS ALONG THE AL-CAN BORDER THROUGH
TUESDAY.  THIS WILL MEAN A RAPID TRANSITION FROM SEASONABLE TEMPS TO
WELL ABOVE AVERAGE TEMPS FOR THE INTERIOR THIS WEEK. SIGNIFICANT
WARMING NOTED ON THE 12Z PAFA SOUNDING AT ALL LEVELS. THE MUCH
WARMER NAM MOS TEMPS LOOK LIKE A BETTER FIT FOR THE PATTERN AS 850
MB TEMPS CLIMB TO +14 TO +17C ACROSS MUCH OF THE INTERIOR BY TUE
AFTERNOON. THE ONLY CAVEAT IS THAT AREAS THAT GET SMOKED IN WILL
BE SEVERAL DEGREES COOLER. AS THE UPPER RIDGE RE-ORIENTS TODAY A
SHORTWAVE WILL QUICKLY ZIP ACROSS THE UPPER KOYUKUK VALLEY AND
THEN ACROSS THE SOUTHEAST BROOKS RANGE THIS EVENING. A FEW SHOWERS
ARE LIKELY THIS MORNING TO THE WEST OF BETTLES...BUT AS THE WAVE
PUSHES EAST TODAY IT IS UNLIKELY THAT THERE WILL BE ANYTHING MORE
THAN A VERY ISOLATED SHOWER AS IT MOVES INTO AN AREA OF DRIER AIR.

WEST COAST...A FRONTAL BOUNDARY IS SEEN ON SATELLITE PIX THAT
EXTENDS FROM THE CHUKOTSK PENINSULA TO THE SOUTHERN ALEUTIANS THAT
WILL CONTINUE TO GET SHEARED APART AND WEAKEN. ELSEWHERE A 1000 MB
LOW SOUTH OF THE ALEUTIANS THAT APPEARS FAIRLY DISORGANIZED LIFTS
NORTH INTO THE SOUTHERN BERING SEA THE NEXT COUPLE OF DAYS. THIS
LOW WILL BRING SOME SHOWERS TO MAINLY THE SOUTHWEST ZONES TUESDAY
AFTERNOON THROUGH WEDNESDAY. THE FRONTAL BOUNDARY ASSOCIATED WITH
THIS LOW LOOKS TO BECOME MORE RAGGED WEDNESDAY BUT MAY TOUCH OFF
ISOLATED CONVECTION.

NORTH SLOPE...MAINLY DRY WEATHER FOR THE NEXT FEW DAYS WITH NOTHING
MORE THAN ISOLATED SHOWERS. THERE WILL BE A COUPLE OF FRONTAL
BOUNDARIES THROUGH WEDNESDAY THAT WILL PUSH EAST. THE FIRST IS
ASSOCIATED A WEAKENING LOW TO THE NORTHEAST OF WRANGEL ISLAND. A
STRONGER FRONT ASSOCIATED WITH THE LOW THAT TREKS ACROSS THE HIGH
ARCTIC REMAINS OFFSHORE AS THE RIDGE BUILDS ACROSS NORTHERN AK
WEDNESDAY.

MID-RANGE...THE LATEST RMOP SHOWS A TRANSITION TO A MUCH MORE
PROGRESSIVE AND LOWER HEIGHT PATTERN ACROSS THE MAINLAND FOR WEEK
TWO...WHICH FROM A CLIMATOLOGICAL STANDPOINT WOULD HAVE MERIT AS
THIS IS TYPICALLY THE WETTEST TIME OF THE YEAR ACROSS THE INTERIOR.
OVERALL THE ENSEMBLES ARE IN GOOD AGREEMENT AS WELL ON THIS PATTERN
SHIFT. HOWEVER UNTIL IT BECOMES MORE CLEAR CUT THAT A MAJOR PATTERN
CHANGE WILL TAKE PLACE WILL NOT PUT COMPLETE FAITH IN ANY BIG
PATTERN CHANGES FOR ANOTHER COUPLE OF DAYS...ESPECIALLY IN LIGHT
OF HOW AMPLIFIED THE PATTERN HAS BEEN SINCE LATE JUNE.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE

&&

.FIRE WEATHER...FIRE WEATHER ISSUES WILL CONTINUE TO TAKE CENTER
STAGE THIS WEEK AS THE RIDGE QUICKLY REBOUND ACROSS THE INTERIOR
EARLY THIS WEEK. THIS WILL BRING A QUICK RETURN TO WELL ABOVE
AVERAGE TEMPERATURES AND LITTLE CHANCE OF CONVECTION ACROSS THE
CENTRAL AND EASTERN INTERIOR WHERE MOST OF THE FIRES ARE LOCATED.
MINIMUM RHS WILL DROP THE NEXT COUPLE OF DAYS WITH RH RECOVERIES
BECOMING INCREASINGLY POOR THE NEXT FEW NIGHTS...ESPECIALLY AT MID-
SLOPE AND ACROSS THE HIGHER AND MORE EXPOSED TERRAIN. THE WIND FOR
THE MOST PART WILL BE ON THE LIGHT SIDE THE NEXT COUPLE OF
DAYS...BUT MAY PICK UP A BIT OUT OF THE EAST/SOUTHEAST TONIGHT AS
THE RIDGE REBUILDS AND A LOW MOVES NORTH INTO THE SOUTHERN BERING
SEA. A LEE SIDE TROUGH INTENSIFIES ON TUESDAY WITH SOME STRONGER
GAP FLOW THROUGH THE AK RANGE PASSES AND IN THE DELTA AREA.

&&

.HYDROLOGY...THE TANANA RIVER AT FAIRBANKS CRESTED EARLY YESTERDAY
MORNING AT 22.38 FT AND HAS BEEN FALLING SINCE. THE FALLS HAVE
EVEN ACCELERATED AT THE TAFA2 GAGE OVERNIGHT. WOULD EXPECT THE
TANANA AT FAIRBANKS TO CONTINUE TO FALL FOR THE NEXT 24 TO 48
HOURS. HIGH FREEZING LEVELS THIS WEEK ACROSS THE EASTERN AK RANGE
WILL RESULT IN A SIGNIFICANT AMOUNT OF GLACIAL MELTING AND HIGH
ELEVATION SNOW MELT RUNOFF FROM THE ALASKA RANGE. GLACIALLY FED
STREAMS WILL RUN HIGH...AND RISES ON THE TANANA SHOULD RESUME AT
TANACROSS BY TUESDAY AND AT FAIRBANKS BY AROUND THURSDAY.
REFRESHED THE SPECIAL WEATHER STATEMENT CONCERNING THE HIGH
WATER LEVELS ON THE TANANA EARLIER THIS MORNING.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FOR AKZ220-AKZ221-AKZ222-AKZ223-AKZ224-AKZ225-
AKZ226.

DENSE SMOKE ADVISORY FOR AKZ220-AKZ221-AKZ224.

SMALL CRAFT ADVISORY FOR PKZ210-PKZ220-PKZ225-PKZ230-PKZ235.
&&

CB AUG 09