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000
FXUS65 KGGW 250326
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
926 PM MDT FRI MAY 24 2013

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SUNDAY...
MADE SOME TWEAKS TO SOME GRIDS BUT THEY WERE MINOR...MAINLY TO
ACCOUNT FOR CURRENT CONDITIONS. REST OF FORECAST LOOKED GOOD. JAMBA

PREVIOUS DISCUSSION...
AN UPPER LEVEL TROUGH OF LOW PRESSURE TO THE WEST WILL MAKE FOR
UNSETTLED WEATHER FOR THE UPCOMING MEMORIAL DAY WEEKEND.

SHOWERS THAT BROUGHT LIGHT RAIN TO PORTIONS OF NORTHEAST MONTANA
THIS MORNING HAVE LIFTED INTO CANADA AS A LOW PRESSURE CENTER
DEEPENS OVER SOUTHERN ALBERTA. DRIER AIR AND MORE STABLE
CONDITIONS HAVE BUILT IN BEHIND THE SHOWERS...MAKING FOR MOSTLY
CLEAR TO PARTLY CLOUDY SKIES THIS EVENING AND OVERNIGHT. WEST WINDS
WILL LIGHTEN AROUND SUNSET...BEFORE SWITCHING AROUND TO THE
SOUTHEAST OVERNIGHT TONIGHT.

SATURDAY CONTINUES TO LOOK FAVORABLE FOR THUNDERSTORM
DEVELOPMENT DURING THE AFTERNOON. SOUTHEAST WINDS WILL STRENGTHEN
THROUGH THE DAY...USHERING IN HIGHER DEWPOINTS OUT OF THE GREAT
PLAINS. THIS MOIST ENVIRONMENT WILL INTERACT WITH DISTURBANCES IN
A SOUTHWEST FLOW ALOFT PROVIDED BY AN UPPER TROUGH OVER THE
PACIFIC NORTHWEST CREATING EXCELLENT POTENTIAL FOR SHOWERS AND
THUNDERSTORMS. STORMS EAST OF A OPHEIM TO GLASGOW TO JORDAN LINE
WILL HAVE THE BEST POTENTIAL TO BECOME ORGANIZED AND SEVERE THANKS
TO A MODERATE SHEAR ENVIRONMENT DRIVEN BY THE LOW LEVEL SOUTHEAST
FLOW. THIS POTENTIAL WILL LINGER INTO SATURDAY EVENING...WITH
SOMEWHAT WEAKER BUT ONGOING THUNDERSTORMS AFTER MIDNIGHT.

SUNDAY A SIMILAR PATTERN WILL CONTINUE...BUT THE BEST POTENTIAL
FOR ORGANIZED STORMS WILL LIE ACROSS AREAS SOUTH OF THE MISSOURI
RIVER. INSTABILITY DOES NOT LOOK QUITE AS IMPRESSIVE AS
SATURDAY...BUT THIS SYSTEM IS DYNAMIC AND CONVECTIVE PARAMETERS
COULD IMPROVE AS WE GET FURTHER INTO THE WEEKEND. GILCHRIST


.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...

MODEL TRENDS CONTINUE TO ADVERTISE SOME FORM OF LOW PRESSURE
TROUGH INFLUENCE OVER NORTHEAST MONTANA THROUGHOUT MOST OF THE EXTENDED
FORECAST PERIOD. THIS WILL LIKELY LEAD TO A LONG PERIOD OF ACTIVE
AND UNSETTLED WEATHER. MADE SOME SMALL ADJUSTMENTS TO THE POPS
GRIDS WHEN EXTENDED MODEL CONSENSUS SHOWED SOME RUN TO RUN
CONSISTENCY. IF THERE WILL BE ANY KIND OF DRY PERIOD BETWEEN
STORMS...IT MAY BE FROM TUESDAY NIGHT THROUGH WEDNESDAY MORNING
WHEN THE TROUGH SPLITS INTO TWO LOBES...ONE SOUTHWARD TOWARD THE
FOUR CORNERS REGION AND THE OTHER NORTHWARD OVER THE CANADIAN
PRAIRIE...WHICH WOULD LIKELY ALLOW A BRIEF PERIOD OF RELATIVELY
CALM CONDITIONS UNDER A SMALL SCALE RIDGE FROM THE SOUTHEAST AS
INDICATED IN THE LONG TERM MODEL HEIGHT SOLUTIONS. BMICKELSON

PREVIOUS LONG TERM DISCUSSION...UPPER TROF ALONG THE WEST COAST
WILL CONTINUE TO DOMINATE THE WEATHER PATTERN THROUGH THE EXTENDED
PERIOD...RESULTING IN UNSETTLED WEATHER AND NEAR NORMAL
TEMPERATURES.

CLOSED LOW CURRENTLY OVER THE PACIFIC NORTHWEST EXPECTED TO LIFT
INTO WESTERN CANADA DURING THE WEEKEND WITH A MORE DISORGANIZED
PATTERN DEVELOPING WITH GREATER MODEL SPREAD. OVERALL PATTERN IS
FOR WEST COAST TROF TO DIG INTO THE DESERT SOUTHWEST WITH SOME
SPLITTING OCCURRING AS ANOTHER UPPER LOW SLIDES FROM ALASKA TOWARD
THE PACIFIC NORTHWEST. THERE CONTINUES TO BE SOME HINTS IN THE
OF RIDGE TILTING BACK INTO THE NORTHERN PLAINS AROUND MID WEEK TO
DIMINISH CONVECTION BUT WITH MODEL SPREAD KEPT POPS NEAR CLIMO.
PRECIPITATION CHANCES WILL INCREASE AGAIN TOWARD THE END OF THE
FORECAST PERIOD WITH BROAD UPPER TROF SPREADING EAST. EBERT

&&

.AVIATION...

VFR CONDITIONS ARE EXPECTED FOR MOST OF THE TAF CYCLE...BEFORE
CONVECTIVE ACTIVITY BEGINS SATURDAY AFTERNOON. INITIALLY...IFR
CONDITIONS OR WORSE WILL BE LIKELY FOR KGDV AND KSDY DURING THE
AFTERNOON HOURS AMID STRONG TO SEVERE THUNDERSTORMS WHICH WILL
SPREAD TO ALL REMAINING TAF SITES THROUGH SATURDAY NIGHT. BMICKELSON

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

WEATHER.GOV/GLASGOW