Dust Devil in Alaska, May 28, 2003

NORTH ALASKA FORECAST DISCUSSION
600 AM ADT WED MAY 28 2003

A GRADUAL SHIFT IN THE UPPER FLOW OVER THE NEXT 24 HOURS OR SO WILL
USHER IN THE FIRST REAL SUMMER WEATHER FOR MUCH OF NORTHERN ALASKA. AN
ELONGATED TROUGH OVER THE WESTERN PART OF THE STATE LINKS A CLOSED UPPER
LOW OVER THE ARCTIC OCEAN TO A STRONG LOW IN THE NORTH PACIFIC. THIS
TROUGH WILL BE PINCHED OFF TODAY BY RIDGING BUILDING INTO THE STATE FROM
THE BERING SEA AND NORTHWEST CANADA. RIDGING ALOFT WITH RISING HEIGHTS
WILL DOMINATE MOST OF NORTHERN ALASKA FOR THE REMAINDER OF THE WEEK.

THE FRONTAL BOUNDARY WHICH HAS BEEN PARKED ACROSS CENTRAL ALASKA THE
PAST FEW DAYS CONTINUES TO PRODUCE SIGNIFICANT PRECIPITATION IN A NARROW
BAND FROM DEADHORSE TO NUNIVAK ISLAND THIS MORNING. THE LIFE OF THIS
BOUNDARY IS SHORT LIVED THOUGH AS THE NORTHERN PORTION WILL CONTINUE TO
BE DRAGGED EAST ACROSS THE ARCTIC COAST...AND THE SOUTHERN PORTION IS
PUSHED WEST ACROSS THE YUKON/KUSKOKWIM DELTA. PRECIPITATION WILL TAPER
OFF AS THIS BOUNDARY IS STRETCHED APART AND SUBSIDENCE ALOFT BEGINS TO
DOMINATE THE REGION.

NORTH SLOPE...RAIN AND SNOW SHOWERS FROM DEADHORSE EASTWARD WILL
DIMINISH THROUGH THE DAY AS THE FRONTAL BOUNDARY HEADS INTO CANADA. A
WARM FRONT MOVING NORTH ACROSS THE CHUKOTSK PENINSULA AND CHUKCHI SEA
TODAY/TONIGHT WILL JUST CLIP THE NORTHWEST ARCTIC COAST. THIS IS
EXPECTED TO RESULT IN GUSTY SOUTHWEST WINDS ALONG WITH A SLIGHT CHANCE
OF SOME LIGHT SNOW WEST OF BARROW. OTHERWISE...WARM ADVECTION WILL PUSH
TEMPERATURES ABOVE FREEZING IN ALL ZONES.

WEST COAST...RAIN AND CLOUDS ASSOCIATED WITH FRONTAL BOUNDARY IN THE
WESTERN INTERIOR WILL GRADUALLY DIMINISH INTO THIS EVENING. WARMER AND
DRIER CONDITIONS WITH LIGHT WINDS EXPECTED FOR THU/FRI.

INTERIOR...PRETTY MUCH THE SAME STORY...RAIN AND BROOKS RANGE SNOW ALONG
DISSIPATING FRONTAL BOUNDARY ENDING TODAY. THERMAL TROUGH ALONG THE
ALCAN BORDER MAY TRIGGER SOME ISOLATED CONVECTION IN THE SOUTHEAST
INTERIOR TODAY...BUT NOT UNSTABLE ENOUGH FOR THUNDERSTORM ACTIVITY YET.
MOISTURE AND INSTABILITY WILL INCREASE LATER IN THE WEEK ACROSS THE
EASTERN INTERIOR THOUGH AS AN UPPER TROUGH ROTATES INTO THE NORTHEAST
GULF OF ALASKA.

MEDIUM RANGE...MODELS GENERALLY CONSISTENT INTO THE WEEKEND. RIDGING
POKING INTO THE STATE FROM THE YUKON TERRITORY WILL LIFT NORTH AND
WEAKEN SOME AS A SERIES OF TROUGHS FROM THE GULF SWING INTO THE SOUTHERN
INTERIOR. THEREFORE...EXPECT INCREASE IN CONVECTION FROM EAST TO WEST
ACROSS THE FORECAST AREA AND THE POSSIBLITY OF THUNDERSTORMS.

.AFG...WATCH/WARNING SUMMARY
PUBLIC...WIND ADVISORY ZONE 201.
MARINE...SMALL CRAFT AREA 10B AND 11A.
FIRE WEATHER...NONE.

EWP MAY 03