Area Forecast Discussion
Issued by NWS Glasgow, MT

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS65 KGGW 080058
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
658 PM MDT TUE JUL 7 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH THURSDAY...

EVENING UPDATE...
UPDATE WAS A LITTLE EARLY TONIGHT AND WAS FOCUSED ON FILLING IN
SOME SHOWERS ACTIVITY THAT IS TAKING PLACE ACROSS THE FAR
NORTHEASTERN CORNER OF THE CWA WHERE RADAR TRENDS ARE SHOWING
ISOLATED EVENING SHOWERS.

SMOKE WAS ALSO REMOVED FROM THIS EVENING AS THE LOCAL 4 ASOS/AWOS
SENSORS ARE REPORTING 10 SM. THIS WILL LIKELY CHANGE AFTER
MIDNIGHT AS THERE ARE SOME SENSORS NORTH OF THE INTERNATIONAL
BORDER THAT ARE DIPPING BELOW 10 SM AND VIS SATELLITE SHOWS A VERY
WISPY FILAMENT DRIFTING IN FROM AROUND REGINA. GAH


PREVIOUS SHORT TERM DISCUSSION...
SATELLITE VIS IMAGERY CLEARLY REVEALS WILDFIRE SMOKE COMING IN
WAVES FROM TWO DIRECTIONS...FROM THE NORTH AND FROM THE WEST. SO
WILL MAINTAIN AREAS OF SMOKE IN THE WX GRIDS TONIGHT.

THE FORECAST PERIOD BEGINS WITH THE PERSISTENT HIGH PRESSURE IN
THE WEST AND A BROAD TROUGH ACROSS CANADA ANCHORED BY A CLOSED
LOW PRESSURE SYSTEM NEAR HUDSON BAY. THEN OFF THE WEST COAST OF
CALIFORNIA IS ANOTHER CLOSED LOW THAT WILL MOVE INLAND BY
TOMORROW. THE BASE OF THAT TROUGH WILL BE PICKING UP PACIFIC
MOISTURE AND EJECTING IT INTO THE GREAT BASIN REGION AND THE
CENTRAL ROCKY MOUNTAINS.

THE UPPER FLOW PATTERN THIS EVENING WILL BE GENERALLY ZONAL WITH A
SLIGHT NORTHWEST COMPONENT. THE CANADIAN LOW NUDGES A SECONDARY
COLD FRONT SOUTH THROUGH NORTHEAST MONTANA THAT WILL MAINLY KEEP
THE HOT AIR OF THE WESTERN HIGH PRESSURE FROM MOVING INTO THE
LOCAL AREA ON WEDNESDAY. THE INITIAL COLD FRONT THAT PASSED
THROUGH EARLIER TODAY WILL BE THE MAIN FOCAL POINT OF THE SHOWERS
AND THUNDERSTORMS THIS EVENING...WHICH WILL MAINLY OCCUR TO OUR
EAST...WEST AND SOUTH. THE SPC SSEO SHOWS THE BEST OPPORTUNITY FOR
STRONG THUNDERSTORMS TO BE IN A NE-TO-SW ORIENTATED AREA JUST TO
THE EAST AND SOUTH OF OUR YELLOWSTONE RIVER VALLEY REGION. A FEW
THUNDERSTORMS MIGHT BEGIN IN OUR AREA THEN GROW AS THEY MOVE EAST
INTO THE DAKOTAS.

THURSDAY...THE FRONTAL BOUNDARY MOVES OFF WELL TO THE NORTH AND
THE WESTERN RIDGE SPREADS HOT AIR INTO MONTANA. EXPECT
TEMPERATURES TO RISE ABOVE NORMAL...AT LEAST 10F ABOVE NORMAL. BY
00Z FRIDAY THE CALIFORNIA TROUGH WILL BE SENDING MORE MOISTURE
THAT WILL REACH INTO SOUTHERN MONTANA BUT WILL NOT QUITE REACH THE
LOCAL AREA.

SCT

.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
AFTERNOON UPDATE...MOSTLY TWEAKS MADE WITH NO SIGNIFICANT CHANGES.
THE TWO BIGGEST CONCERNS IN THE EXTENDED IS THE RETURN TO WARMER
AND DRIER CONDITIONS AS WE GET DEEPER INTO FIRE SEASON. THE OTHER
CONCERN FOR PUBLIC AND FIRE WEATHER FORECASTING IS THE TIMING ON
THE BROAD AREA SURFACE LOW COMING THROUGH FRIDAY NIGHT INTO
SATURDAY. THIS IS A SIGNIFICANT LOW SIMILAR TO THE ONE ON THE
4TH OF JULY AND WE COULD SEE A SIMILAR SITUATION WITH THE LOW IN
THE AREA KICKING OFF SOME AIR MASS THUNDERSTORMS AHEAD OF THE
FRONT AND THEN MORE SIGNIFICANT STORMS AS THE FRONT MOVES THROUGH.
AT THIS TIME I`M NOT SURE THE WINDS IN THE FORECAST PORTRAY THE
SITUATION REAL WELL BUT EVERY MODEL IS SHOWING SOMETHING SLIGHTLY
DIFFERENT WITH THE FRONTAL PASSAGE. WITH A TIGHT GRADIENT...THE
WINDS WILL BE AN ISSUE AT TIMES...AND THAT IS OF CONCERN WITH A
LARGE FISHING TOURNAMENT ON FORT PECK THIS WEEKEND AS WELL AS THE
NON-TOURNAMENT OUTDOOR RECREATIONALISTS WHO WILL BE CAMPING OUT
THERE. FRANSEN


PREVIOUS DISCUSSION...
SOUTHWEST FLOW ALOFT WITH AN UPPER TROUGH TO THE WEST WILL
PREVAIL FROM THURSDAY NIGHT THROUGH SUNDAY. THIS FLOW WILL ALLOW
MOISTURE FROM THE PACIFIC TO MOVE TOWARDS MONTANA. COMBINE THIS
MOISTURE WITH SOME SHORTWAVES AND UNSTABLE AIR MASS TO BRING
CHANCES FOR SHOWERS AND THUNDERSTORMS. ONE OF THESE WAVES IS TIMED
FOR FRIDAY AFTERNOON AND EVENING WITH A LOW PRESSURE AND FRONTAL
SYSTEM. A SOMEWHAT STRONGER SHORTWAVE IS FORECASTED BY BOTH THE
GFS AND ECMWF TO MOVE THROUGH NORTHEAST MONTANA SATURDAY AFTERNOON
AND EVENING WITH THE LOW PRESSURE SYSTEM STILL IN THE AREA. THIS
WAVE WILL BRING A COLD FRONT THROUGH THE AREA SATURDAY NIGHT.

UPPER RIDGE BUILDS OVER EASTERN MONTANA ON SUNDAY AND REMAINS IN
PLACE MONDAY AND TUESDAY. HOT AND DRY WEATHER CAN BE EXPECTED MOST
OF THE TIME. HOWEVER...WEAK SHORTWAVE TROUGH ARE EXPECTED TO MOVE
ACROSS THE RIDGE AT TIMES THAT COULD BRING AN ISOLATED
THUNDERSTORM. FORRESTER


&&

.AVIATION...

FLIGHT CATEGORY: VFR EXPECTED...OUTSIDE OF POSSIBLE MIXED MVFR
AT TIMES DUE TO SMOKE/HAZE FROM CANADIAN FIRES. THE SITE WITH THE
GREATEST POTENTIAL FOR REDUCED VISIBILITY IS KGGW.

SKY COVER: LINGERING RAIN SHOWERS ASSOCIATED WITH THE COLD FRONT
FROM EARLIER TODAY WILL EVENTUALLY DIMINISH AWAY TONIGHT. EXPECT
SKIES TO GENERALLY CLEAR AFTER MIDNIGHT (06Z) TONIGHT.

WINDS: FROM THE NORTH AND NW 10 TO 15 KNOTS TONIGHT BEHIND THE
COLD FRONT...BECOMING FAIRLY LIGHT BY MORNING. BMICKELSON


&&

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


&&

$$

WEATHER.GOV/GLASGOW




USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.