Area Forecast Discussion
Issued by NWS Glasgow, MT

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FXUS65 KGGW 020207
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
807 PM MDT WED JUL 1 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH FRIDAY...
UPDATE...
SHOWERS AND THUNDERSTORMS HAVE PUSHED MAINLY INTO THE EASTERN
ZONES THIS EVENING...AND SHOULD PUSH INTO THE DAKOTAS OVER THE
NEXT FEW HOURS. SOME OF THIS CONVECTIVE ACTIVITY MAY BE
ACCOMPANIED BY SMALL HAIL OR GUSTY WINDS BUT THAT SHOULD BE ABOUT
IT. OTHER CONCERN WILL BE LINGERING SMOKE WITH CANADIAN FIRES OVER
THE NEXT COUPLE OF DAYS. OTHERWISE A QUIET WEATHER DAY EXPECTED
AHEAD FOR THURSDAY FOR THE MOST PART. MALIAWCO

PREVIOUS DISCUSSION...

NORTHWEST FLOW ALOFT WILL CONTINUE TONIGHT AS A SHORTWAVE TROUGH
MAKES ITS WAY TROUGH NORTHEAST MONTANA. THIS FEATURE WILL BRING
WIDESPREAD TO SCATTERED SHOWERS AND THUNDERSTORMS TO THE REGION AS
IT PASSES THIS AFTERNOON AND EVENING. THERE REMAINS A THREAT FOR
AN ISOLATED SEVERE STORM TO POP UP...BUT OVERALL GENERAL
THUNDERSTORMS ARE EXPECTED THROUGH THE EVENING HOURS.

A NORTHERLY COMPONENT TO THE WINDS WILL CONTINUE SMOKE FROM
CANADIAN FOREST FIRES ACROSS THE REGION TONIGHT THROUGH THURSDAY
NIGHT.

THURSDAY WEAK RIDGING WILL MAKE FOR MAINLY DRY CONDITIONS...WITH
JUST AN ISOLATED STORM POSSIBLE DURING THE AFTERNOON ALONG THE
NORTH DAKOTA BORDER. THURSDAY NIGHT HIGH PRESSURE WILL CONTINUE...MAKING
FOR DRY CONDITIONS WITH MOSTLY CLEAR SKIES. LIGHT NORTHERLY WINDS
WILL KEEP A MENTION OF SMOKE IN THE FORECAST. GILCHRIST

.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...

GREATEST FORECAST CHALLENGE IN THE EXTENDED PERIOD IS THE STRONG
COLD FRONT EXPECTED ON SATURDAY EVENING AND ITS POSSIBLE IMPACTS
ON FORTH OF JULY FIREWORKS SHOWS ACROSS THE REGION. MODELS ALSO
INDICATING POSSIBLE DRY THUNDERSTORMS AS INSTABILITY IS HIGH BUT
QPF AND PRECIP OUTPUT IS NEXT TO NOTHING. THE FORTH OF JULY WILL
BE HOT WITH MID-DAY WIND UP TO 15 MPH FROM THE SOUTH. THE COLD
FRONT WILL MOVE INTO THE AREA SOMETIME LATER SATURDAY AFTERNOON
WITH WINDS UP TO 20 MPH FROM THE NORTHWEST...THEN FROM THE NORTH
SATURDAY EVENING UP TO 30 MPH.

TRIED TO UPDATE THE WIND GRIDS ON SATURDAY WITH THE HIGHER END OF
FORECAST GUIDANCE. THE REMAINDER OF THE EXTENDED PERIOD POPS WERE
ADJUSTED WITH A BLEND OF THE GFS AND EC WITH HIGHER CONFIDENCE
WHERE MODELS SHOWED THE BEST AGREEMENT. BMICKELSON

ZONAL FLOW ALOFT ON SATURDAY WILL PUSH ACROSS THE NORTHERN HIGH
PLAINS ALONG THE NORTHERN PERIPHERY OF A STRONG RIDGE DOMINATING
OVER THE WESTERN CONUS. MODEL 850MB TEMPERATURES WILL RANGE FROM
+22C NEAR THE CANADIAN BORDER TO +28C IN THE FAR SOUTHWEST ZONES
ON SATURDAY AFTERNOON. MEANWHILE...A SHORTWAVE TROUGH SLIDING DOWN
BRITISH COLUMBIA WILL APPROACH THE REGION...BUT THERE REMAINS SOME
QUESTION IN TIMING AND EVOLUTION. THE GFS IS MORE PROGRESSIVE AND
WOULD HAVE AN ASSOCIATED SURFACE COLD FRONT PUSHING THROUGH THE
REGION LATE SATURDAY AFTERNOON...WHILE THE ECMWF IS MORE
SUPPORTIVE OF EVENING AND NIGHTTIME PASSAGE. ALTHOUGH...EVEN THE
LATEST ECMWF SHOWS TIGHTLY PACKED 850MB THERMAL GRADIENT NEAR THE
CANADIAN BORDER BY LATE SATURDAY AFTERNOON. WITH THIS IN
MIND...HAVE FAIR AMOUNT OF CONFIDENCE ON A HOT DAY FOR AREAS SOUTH
OF THE MISSOURI RIVER. HIGHS SHOULD REACH THE MID...EVEN UPPER
90S. NEAR THE CANADIAN BORDER...UNCERTAINTY REMAINS BUT IT WILL
LIKELY BE AT LEAST SOMEWHAT LESS HOT DUE TO EARLY FROPA AND
INCREASED CLOUDINESS OUT AHEAD OF IT. WILL GO WITH UPPER 80S TO
NEAR 90 IN THOSE LOCATIONS FOR NOW.

EXPECT A STRONG WIND SHIFT WITH THE FRONT...SOUTH WINDS BECOMING
NORTH AND NORTHWEST...WITH COLD AIR ADVECTION HELPING TO MIX DOWN
SOME GUSTY CONDITIONS. WOULD NOT BE SURPRISED TO SEE 15-25 MPH
SUSTAINED WITH GUSTS TO 35 MPH IN THIS ENVIRONMENT. THESE CHANGING
CONDITIONS ARE OF SIGNIFICANT TO THOSE WITH HOLIDAY PLANS ON THE
NIGHT OF THE 4TH...AND THESE CONDITIONS MAY BE ENOUGH TO PROMPT
ISSUANCE OF A LAKE WIND ADVISORY DOWN THE ROAD. MODEL GUIDANCE IS
ALSO SUPPORTIVE OF AT LEAST ISOLATED TO WIDELY SCATTERED SHOWERS
AND THUNDERSTORMS DURING THE AFTERNOON...LINGERING INTO THE NIGHT.
HOWEVER...TIMING/PLACEMENT REMAINS VERY MUCH IN QUESTION AT THIS
POINT...BUT BETTER CONSENSUS FOR NOW APPEARS TO BE NEAR THE
CANADIAN BORDER.

TEMPERATURES WILL BE COOLER IN THE WAKE OF THE FRONT...WITH HIGHS
IN THE 70S AND LOW 80S SUNDAY INTO THE MIDDLE OF NEXT WEEK. WEAK
SHOWER/THUNDERSTORM CHANCES WILL HINGE ON SHORTWAVES EMBEDDED IN
THE FLOW. AT THIS POINT THE ONE WITH MOST PROMISE APPEARS TO BE
TOWARD THE END OF THE PERIOD. MALIAWCO


&&

.AVIATION...
FLIGHT CATEGORY: MAINLY MVFR.

SYNOPSIS: SMOKE FROM CANADIAN WILDFIRES WILL PERSIST OVER
NORTHEAST MONTANA INTO TUESDAY AS LOW LEVEL NORTH TO NORTHWEST
FLOW CONTINUES.

THUNDERSTORMS THIS AFTERNOON WILL ALSO HAVE THE POSSIBILITY TO
BRING GUSTY ERRATIC WINDS AS WELL AS MVFR CIGS AND OR VISIBILITY
TO ANY OF THE TERMINALS THROUGH EARLY THURSDAY.

WINDS: GENERALLY NORTH TO NORTHWEST 8-12MPH.

GILCHRIST


&&

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

&&

$$

WEATHER.GOV/GLASGOW





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