Funnel Cloud in Alaska, July 28, 2004

NORTH ALASKA FORECAST DISCUSSION
600 AM ADT WED JUL 28 2004

.DISCUSSION...
ALL OF THE MAJOR BRAND NAME COMPUTER FORECASTS ARE IN ALMOST
SEAMLESS AGREEMENT TODAY, WHICH MAKES THE FORECAST OUTCOME PRETTY
BELIEVABLE. THIS IS EVEN MORE SO SINCE THE MRF AND GFS (GLOBAL
FORECAST SYSTEM OF NCEP, FORMERLY KNOWN AS THE AVIATION MODEL)
HAVE BEEN FORECASTING ESSENTIALLY THE SAME OUTCOME OVER THE
ALASKAN PART OF THE REALM FOR AT LEAST TWO DAYS NOW.

TO WIT: ALOFT, THE CLOSED LOW WILL WEAKEN AND ON THURSDAY WILL
BECOME PART OF A BROAD TROUGH ALOFT OVER THE WEST 2/3 OF THE
MAINLAND. OF GREAT IMPORTANCE IS THE INCOMING STRONG COLD LOW
ALOFT, WHICH WILL MOVE ACROSS THE CHUKCHI SEA FROM THE WEST
STARTING THURSDAY EVENING, AND ARRIVE IN AREA 11A (WEST ALASKAN
ARCTIC) FRIDAY EVENING. NOTHING LIKE THIS HAS HAPPENED IN THE
REALM FOR QUITE A FEW MONTHS. A SURFACE LOW WITH RATHER WEAK
CIRCULATION WILL COME IN JUST A LITTLE TO THE EAST (AHEAD) OF THE
LOW ALOFT.

ON FRIDAY NIGHT AND SATURDAY THE COLD LOW ALOFT WILL HEAD
SOUTHEAST, AND REACH THE CENTRAL BROOKS RANGE...AND THEN THE
FORTYMILE COUNTRY SUNDAY EVENING.

THIS SERIES OF EVENTS WILL BRING MUCH COLDER AIR ALOFT TO THE WEST
ARCTIC ON FRIDAY...AND OVER THE INTERIOR FRIDAY NIGHT/SATURDAY TO
STAY THE REST OF THE WEEKEND. THE FIRST SNOW OF THE SEASON IS A
REAL POSSIBILITY IN THE WEST ARCTIC AND WESTERN BROOKS RANGE
FRIDAY NIGHT...AND OVER THE HIGH COUNTRY OF THE BROOKS RANGE AND
OF THE INTERIOR SATURDAY THROUGH SUNDAY. AFTERNOON TEMPERATURES IN
THE INTERIOR THIS WEEKEND SHOULD REMAIN LARGELY CONFINED TO THE
50S, ALMOST 30 DEGREES COOLER THAN DURING THE HEAT OF THIS YEARS
SUMMER IN THE SECOND HALF OF JUNE.

ALSO IMPORTANT HERE IS THE STRONG SHOT OF WESTERLIES ALOFT THAT
THIS SCENE WILL BRING IN OVER NORTHERN ALASKA FRIDAY THROUGH
SATURDAY, FOLLOWED BY COOL NORTHWEST FLOW ON SUNDAY. THIS IS A
FINE PATTERN FOR WIDESPREAD LIGHT RAIN (AND SNOW IN THE
HIGHLANDS.)

IRONICALLY, THE MEDIUM RANGE FORECASTS SHOW THE END OF THIS
OUTBREAK OF COOL WEATHER COMING JUST ABOUT AS ABRUPTLY AS ITS
ONSET. THE COLD AIR ALOFT WILL HEAD TOWARD SOUTHEAST ALASKA ON
MONDAY...AND MAKE WAY FOR A FAIRLY STRONG RIDGE ALOFT TO BUILD
OVER THE WEST MAINLAND ON TUESDAY. THE LIGHT NORTHEAST WINDS ALOFT
FORECAST TUESDAY LOOK LIKE A FINE PATTERN FOR CLEARING...AND A
RECOVERY OF AFTERNOON TEMPERATURES BACK INTO THE LOWER 70S.

IT IS HARD TO GET A GOOD REALITY CHECK ON THIS FORECAST IN THE
BEGINNING STAGES OF WHAT LOOKS LIKE WILL BE A MAJOR EXCURSION FROM
SUMMER WEATHER AS WE HAVE KNOWN IT THIS YEAR. WE DO HAVE ENOUGH
SURFACE DATA TO CHECK THE WEST CHUKCHI SEA. AT 10 PM ADT
TUESDAY...A NEW SURFACE LOW APPEARED NEAR 78 DEGREES NORTH/140
DEGREES EAST. SINCE MOST OF THE CIRCULATION IN THIS SYSTEM IS
ALOFT, A STRONG CONFIDENCE CHECK ON IT WILL NOT BE POSSIBLE. BUT
SO FAR, THE RIGHT INGREDIENTS APPEAR TO BE COMING TOGETHER.

AND WITH LITTLE DOUBT, THE HOT DRY WEATHER OF EARLIER THIS SUMMER
IS NOW CONSIGNED TO THE PAST. THERE SHOULD BE WIDESPREAD LIGHT
RAIN (AND HIGHLAND RAIN AND SNOW) OVER NEARLY ALL OF NORTHERN
ALASKA THIS WEEKEND.

IN THE MORE NEAR FUTURE, THE ETA MODEL FORECASTS UNSTABLE AIR OVER
THE NORTHERN INTERIOR TODAY AND THURSDAY...SO THERE MAY BE A FEW
THUNDERSTORMS UP THERE IN THE LATE AFTERNOON AND EVENING HOURS. ON
TUESDAY, THERE WERE ONLY 28 STRIKES RECORDED OVER ALASKA BY THE
LIGHTNING DETECTION SYSTEM - A FAR, FAR CRY FROM EARLIER THIS
SEASON.

.HYDRO...NOT ENOUGH RAIN YET TO BRING UP THE CREEKS. FREEZING
LEVELS REALLY COMING DOWN THIS WEEKEND.
.FIRE WEATHER...SUDDENLY, ITS QUIET. THE WINDS DOWN, HUMIDITY IS
UP, AND IT LOOKS LIKE A RAINY 5 DAYS COMING.

.AFG WATCH/WARNING/ADVISORIES...
PUBLIC...DENSE FOG ADVISORY CONTINUING OVER SAINT LAWRENCE ISLAND
AND BERING STRAIT COAST TODAY AND TONIGHT.
MARINE...SMALL CRAFT ADVISORY AREA 11A.

TF JUL 04