143
FXUS65 KGGW 130911 AAA
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
311 AM MDT TUE AUG 13 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY...
A SLOW MOVING FRONTAL BOUNDARY WILL COMBINE WITH SHORTWAVES
OVERTOPPING AN UPPER RIDGE AND MOIST UNSTABLE AIRMASS TO PRODUCE
THUNDERSTORMS AT TIMES TODAY THROUGH WEDNESDAY NIGHT. WITH
PRECIPITABLE WATER EXPECTED TO BE BETWEEN AN INCH AND 1.25
INCHES... LOCALLY HEAVY RAIN IS ALSO POSSIBLE WHICH MAY PRODUCE
FLASH FLOODING. MODELS DIFFER IN WHEN AND WHERE IT WILL RAIN WITH
THE INDIVIDUAL WAVES. WILL BROADBRUSH ISOLATED TO SCATTERED
THUNDERSTORMS TODAY AND TONIGHT WITH HEAVY RAIN POSSIBLE FOLLOWED
BY ISOLATED TO SCATTERED THUNDERSTORMS ON WEDNESDAY AND A CHANCE
OF THUNDERSTORMS WEDNESDAY NIGHT.
UPPER RIDGE STRENGTHENS OVER THE FORECAST AREA ON THURSDAY WITH
SOMEWHAT DRIER... WARMER AND MORE STABLE AIRMASS WHICH WILL LIMIT THE
CHANCES OF THUNDERSTORMS. WITH SHORTWAVE LACKING IN THE FLOW
ALOFT... WILL GO WITH A DRY FORECAST FOR NOW. FORRESTER
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
THE LONG TERM FORECAST PERIOD BEGINS WITH A STRONG UPPER LEVEL
RIDGE IN PLACE WITH ITS AXIS DIRECTLY THROUGH NORTHEAST MONTANA.
EXCELLENT MODEL AGREEMENT IN KEEPING THE ENTIRE CWA CONSEQUENTLY
DRY. THIS WILL ALLOW THE HOTTEST TEMPERATURES OF THE SUMMER SEASON
TO FINALLY ARRIVE...TOPPING OUT IN THE LOW TO MID 90S...ALTHOUGH
SOME NUMERICAL GUIDANCE SUGGESTS THAT EVEN THIS MAY BE TOO
CONSERVATIVE FOR FRIDAY AND SATURDAY HIGH TEMPERATURES. FOR NOW
FELT IT WAS BEST TO SHOW A GRADUAL INCREASE UNTIL MORE MODEL
CONSENSUS IS EVIDENT.
WITH A COOL FRONT SET TO MOVE THROUGH THE AREA ON SATURDAY
NIGHT...SCATTERED SHOWERS AND THUNDERSTORMS WILL BE ON THE HEELS
OF SOME MUCH AWAITED NORTHWESTERLY SURFACE WINDS UNDER
SOUTHWESTERLY FLOW ALOFT COURTESY OF THE UPPER LEVEL TROUGH OVER
THE PACIFIC NORTHWEST COASTAL AREA. THIS UNSETTLED PERIOD SHOULD
REMAIN OVER THE REGION WHILE A SHORT WAVE TROUGH PUSHES THROUGH
THE AREA THROUGH MONDAY MORNING...WITH THE BEST CHANCES FOR PRECIP
FOCUSED FROM SATURDAY NIGHT THROUGH SUNDAY MORNING.
MONDAY AND BEYOND...STRONG SUMMER RIDGING FROM THE SOUTHWEST MOVES
IN AGAIN TO CUT OFF THE PRECIPITATION WITH TEMPERATURES WARMING
BACK UP INTO THE 90S.
&&
.AVIATION...
PERSISTENT OVERNIGHT THUNDERSTORMS WILL BRIEFLY IMPACT KGGW EARLY
THIS MORNING WITH GUSTY WEST WINDS UP TO 35 MPH WITH A FEW
THUNDERSTORMS AND SOME MVFR CONDITIONS. OTHERWISE...VFR CONDITIONS
WILL PREVAIL FOR ALL TAF SITES FOR THE REMAINDER OF THE TAF
PERIOD. EASTERLY WINDS FROM 5 TO 10 KTS EARLY THIS MORNING WILL
BECOME SLIGHTLY GUSTY DURING PEAK HEATING. TOWARD THE END OF THIS
TAF CYCLE...VCTS MAY INTRODUCE SOME MVFR CONDITIONS AGAIN...BUT
IT IS A BIT TOO SOON TO INDICATE THAT IN A PREVAILING GROUP.
MICKELSON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW