Area Forecast Discussion
Issued by NWS Glasgow, MT

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000
FXUS65 KGGW 012014
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
214 PM MDT SAT AUG 1 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH MONDAY...
HOT AND DRY CONDITIONS EXISTED ACROSS THE CWA THIS AFTERNOON WITH
TEMPERATURES REACHING THE 90S ACROSS MOST OF THE CWA AND RH/S MAINLY
IN THE TEENS. BUT A BACKDOOR COLD FRONT IS MOVING SOUTH THROUGH SASK
AND WILL COOL THINGS OFF A BIT SUNDAY...POSSIBLY MORE THAN 10
DEGREES IN SOME PLACES OVER TODAY.

MODELS HAVE INCREASED THE EFFECT OF THE FRONT AS IT PASSES SOUTH
THROUGH THE CWA TONIGHT IN THE FORM OF STRONGER NORTH WINDS. AIR MASS
QUITE A BIT COOLER BEHIND THE FRONT WITH TEMPERATURES THIS HOUR IN
THE UPPER 60S IN SOME PLACES. AIR MASS SHOULD BE MODIFIED A BIT
SUNDAY ACROSS NE MT WITH READINGS RANGING FROM NEAR 80 ACROSS THE
NE ZONES TO NEAR 90 SOUTH OF FORT PECK LAKE. AIR MASS IS EXPECTED
TO BE BETTER IN TERMS OF HUMIDITY TOO.

ON MONDAY...AN UPPER RIDGE BUILDS INTO MONTANA BUT AN EAST WIND WILL
ADVECT IN COOLER AIR FROM OUR EAST. THEREFORE TEMPERATURES WILL
BE SIMILAR TO SUNDAY/S. TFJ

.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...

AFTERNOON UPDATE...
CHANCES FOR RAIN SHOWERS FROM TUESDAY AFTERNOON THROUGH THURSDAY
CONTINUE TO CREEP UPWARD. SOME CHANGES IN TIMING OF STORMS TUESDAY
AFTERNOON HAVE COME OUT... HOWEVER WITH THE STORMS SYSTEM SLOWING DOWN
IN ARRIVAL TIME AND IMPACTING THE AREA MORE DURING THE LATE
AFTERNOON AND EVENING HOURS. THIS COULD INCREASE CHANCES FOR
SEVERE WEATHER DUE TO COUPLING WITH PEAK HEATING.

MODEL COHESION AND CONFIDENCE NOW BREAKS DOWN AT THURSDAY NIGHT
WHEN THE BRITISH COLUMBIA LOW MOVES ACROSS THE ROCKIES... OR
DOESN`T... DEPENDING ON THE MODEL. GAH

PREVIOUS LONG TERM DISCUSSION...
THE EXTENDED PERIOD KICKS OFF MONDAY NIGHT WITH 00Z MODEL GUIDANCE
IN FAIRLY GOOD AGREEMENT HAVING AN UPPER RIDGE ESTABLISHED OVER
THE NORTHERN HIGH PLAINS...WHICH SHOULD MAINTAIN WARM AND DRY
CONDITIONS ACROSS THE REGION.

AN UPPER LOW/TROUGH OFF THE COAST OF BRITISH COLUMBIA WILL
TRANSLATE EAST ALLOWING THE RIDGE AXIS TO TRANSLATE FURTHER
DOWNSTREAM OF THE FORECAST AREA. PACIFIC MOISTURE AND INSTABILITY
LOOK TO INCREASE OUT AHEAD OF THIS SYSTEM AND SO INCREASING
CHANCES FOR SHOWERS AND THUNDERSTORMS BY MIDWEEK LOOK TO BE A SURE
BET...THOUGH TIMING OF EMBEDDED UPPER LEVEL SHORTWAVE IMPULSES
WILL ALLOW FOR EXTRA FORECAST DETAIL TO BE ADDED IN TIME. FOR NOW
KEPT A BROAD BRUSH OF CHANCE POPS DURING THIS PERIOD.

AS 00Z ENSEMBLE 500MB HEIGHTS EXHIBIT INCREASING RELATIVE SPREAD
DURING THE LATTER PART OF NEXT WEEK...FORECAST DROPPED OFF AND SO
POPS/TEMPERATURES WERE TRENDED FAIRLY CLOSE TO CLIMATOLOGY. DO
EXPECT BETTER HANDLE ON THIS PERIOD AS IT ENTERS THE FORWARD PART
OF THE LONG RANGE FORECAST AND MODEL GUIDANCE SHOWS BETTER RUN TO
RUN CONSISTENCY AND CONSENSUS ALLOWING FOR IMPROVED FORECAST
CONFIDENCE. MALIAWCO


&&

.AVIATION...
FLIGHT CATEGORY: VFR

SYNOPSIS: AS A WARM FRONT EXITS THE AREA MID AFTERNOON A COLD
FRONT WILL QUICKLY FOLLOW IT AND SHIFT WINDS A COUPLE
TIMES.

AREA WINDS: OUT OF THE WEST TO NORTHWEST AT 10 TO 20 KTS
SUSTAINED WITH GUSTS TO 25 KTS LATE THIS AFTERNOON... CALMING TO
LESS THAN 10 KTS AND VEERING TO THE NORTHEAST OVERNIGHT.

GAH

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.

&&

$$

WEATHER.GOV/GLASGOW





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