Area Forecast Discussion
Issued by NWS Glasgow, MT

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FXUS65 KGGW 051451
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
851 AM MDT THU MAY 5 2016

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SATURDAY...
UPDATE...

NO MAJOR CHANGES WERE NEEDED WITH THE FORECAST AS WEATHER ELEMENTS
LOOK ON TRACK FOR NOW. EXPECT CONVECTION TO INCREASE FROM WEST TO
EAST THIS EVENING FOLLOWING THE SPC SSEO GUIDANCE WHICH IS
CONSISTENT WITH THE NEW 12Z NAM COMING IN. MALIAWCO

PREVIOUS DISCUSSION...

AFTER THE THREAT OF MANY LOCATIONS RECORDING NEW RECORD HIGH
TEMPERATURES TODAY...THE GREATEST FORECAST CHALLENGE IN THE SHORT
TERM WILL BE THE PLACEMENT AND INTENSITY OF ANY RAIN SHOWERS AND
ISOLATED THUNDERSTORMS THIS EVENING AS THE ACTIVE TROUGH OF LOW
PRESSURE OVER THE WESTERN STATES PUSHES PACIFIC MOISTURE UP AND
OVER THE ROCKY MOUNTAINS. MODEL AGREEMENT IS STILL LESS THAN
IDEAL THROUGH EARLY FRIDAY MORNING WITH THE EC COMPLETELY
DRY...THE GEM AND NAM MOSTLY DRY BUT BRINGING SOME PRECIP OVER OUR
NW ZONES...AND THE GFS PUSHING A WIDE BAND OF RAIN SHOWERS THROUGH
OUR CENTRAL CWA.

EVEN THOUGH THE WESTERN TROUGH CLOSES OFF A LARGE CUT-OFF LOW
CENTER OVER THE SIERRA NEVADA...MOST OF THE DYNAMICS FOR PRECIP
FOR NORTHEAST MONTANA WILL RESULT FROM THE NORTHERN STREAM
PORTION OF THE TROUGH PASSAGE. NOT SURE WHICH CAMP WILL PREVAIL.
CHOSE TO PROCEED WITH A ROUGH BLEND. EXPECTING GENERAL
THUNDERSTORM CHANCES FOR THE WESTERN TIER COUNTIES OF OUR CWA
TONIGHT.

BY FRIDAY AFTERNOON...BETTER MODEL AGREEMENT SHOWS UP AS THE
NARROW SEPARATING RIDGE OF HIGH PRESSURE RE-CONNECTS RIGHT
THROUGH NORTHEAST MONTANA AND KEEPS ALL PRECIP WELL SOUTH OF OUR
CWA THROUGH SUNDAY MORNING. BMICKELSON


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
AN UPPER RIDGE WILL BE OVER THE AREA SATURDAY NIGHT WITH DRY WEATHER.
THAT RIDGE WILL MOVE TO THE EAST ON SUNDAY AND AN UPPER TROUGH
WILL MOVE IN FROM THE WEST. SUNDAY WILL REMAIN DRY AS IT LOOKS
LIKE MOISTURE WILL MOVE INTO THE AREA SUNDAY NIGHT AND MONDAY. A
COLD FRONT ASSOCIATED WITH THE SYSTEM WILL MOVE THROUGH EASTERN
MONTANA ON MONDAY. ATMOSPHERE MAY BE UNSTABLE ENOUGH FOR
THUNDERSTORMS MONDAY AFTERNOON AND EVENING. WILL MENTION A SLIGHT
CHANCE FOR NOW.

THE UPPER TROUGH AND MOISTURE WILL REMAIN OVER THE AREA ON
TUESDAY. WILL MAINTAIN A CHANCE OF SHOWERS. ATMOSPHERE MAY BE
UNSTABLE ENOUGH FOR THUNDERSTORMS. WILL MENTION A SLIGHT CHANCE.

MODELS DIFFERENCES START APPEARING TUESDAY NIGHT AND WEDNESDAY AS
GFS WANTS TO MOVE UPPER TROUGH/LOW TO THE EAST AND ECMWF KEEPS AN
UPPER LOW OVER MONTANA. WILL MAINTAIN CHANCE OF SHOWERS.

NEXT THURSDAY...GFS HAS NW FLOW ALOFT WITH SHORTWAVES WHILE THE
ECMWF MOVES THE UPPER LOW TO THE DAKOTAS. WILL CONTINUE A SLIGHT
CHANCE OF SHOWERS. FORRESTER



&&

.AVIATION...
SYNOPSIS:
AN UPPER LEVEL RIDGE WILL CONTINUE OVER THE REGION TODAY. A
SHORTWAVE TROUGH AND COLD FRONT IS EXPECTED TONIGHT.

FLIGHT CATEGORY: VFR.

WX/WIND: NIL SIG THROUGH 00Z...THEN ISOL TO SCT SHOWERS AND
THUNDERSTORMS AND MID LEVEL CLOUDS ARE EXPECTED TONIGHT WITH THE
COLD FRONT. EXPECT LIGHT MAINLY SOUTH TO SW WINDS TODAY. WINDS
WILL BECOME NW TO NORTH 10 TO 20 KNOTS AFTER 06Z TONIGHT AS COLD
FRONT MOVES THROUGH.



&&

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

&&

$$

WEATHER.GOV/GLASGOW


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