123
FXUS65 KGGW 071620
AFDGGW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
920 AM MST SAT NOV 7 2009
SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH MONDAY
THE SHORT TERM FORECAST LOOKS GOOD SO NO CHANGES PLANNED THIS
MORNING. FAIRLY ZONAL FLOW ALOFT ACROSS THE REGION THIS MORNING
WILL KEEP THINGS RATHER DRY ACROSS THE REGION. A WEAK SHORTWAVE
WILL STILL MOVE ACROSS PORTIONS OF NORTHERN WYOMING AND SOUTHERN
MONTANA THIS AFTERNOON. THIS WILL HAVE VERY LITTLE IMPACT ON THE
WEATHER FOR NORTHEASTERN MONTANA. THE ZONAL PATTERN WILL CONTINUE
FOR THE REST OF THE WEEKEND WITH LITTLE IMPACT ON THE WEATHER
OTHER THEN SLIGHT STRONGER AFTERNOON WINDS ON SUNDAY. THE SKY WILL
REMAIN MOSTLY SUNNY TODAY AND PARTLY CLOUDY SUNDAY AFTERNOON AND
DAYTIME HIGHS WILL REMAIN ABOVE NORMAL IN THE MID 50S. RSMITH
PREVIOUS DISCUSSION...A FLAT...MODERATE WESTERLY FLOW ALOFT. A
COOLER AIRMASS HAS ARRIVED FOLLOWING DRY COLD FRONT PASSAGE
YESTERDAY...HOWEVER TEMPS WILL STILL BE ABOVE NORMAL THE NEXT FEW
DAYS. 2 MINOR SHORTWAVES IN THIS FLOW...BUT LITTLE CHANCE OF
PRECIP FROM THEM...AS THERE IS LITTLE UPPER SUPPORT AND MOISTURE
IS GREATLY LACKING...TYPICAL OF THIS TYPE OF PATTERN. NOT MUCH
CHANGE IN AIRMASS TEMPS THRU MON EITHER.
WATER VAPOR SATELLITE CHANNEL SHOWS DRY AIR ALOFT OVER
MT...WHICH WAS SHOWN WELL BY THE 00Z KGGW SOUNDING. WATER VAPOR
ALSO SHOWS A WEAK SHORTWAVE OVER S ID. MODELS AND UPPER FLOW
INDICATE THIS WILL BE STEERED ENE ACROSS N WY/S MT THIS AFTERNOON
AND EVE...WITH LITTLE IMPACT FOR OUR AREA WITH LOTS OF SUNSHINE
EXPECTED.
WINDS HAVE BEEN MUCH SLOWER TO DIMINISH OVERNIGHT THAN EXPECTED IN
SOME PLACES...WHILE OTHER LOWER AREAS HAVE GONE VERY LIGHT.
SURFACE BASED NOCTURNAL INVERSIONS WILL BE RATHER WEAK AND SHALLOW
THIS MORN...SO MIXING OUT BY 10 AM OR SO TODAY...BUT STILL EXPECT
LESSER SPEEDS THAN YESTERDAY. EXPECT MIXING TO AROUND 850 MB...WINDS
AT THAT LEVEL BEING STRONGEST IN OUR NORTHERN ZONES. SURFACE
PRESSURE GRADIENTS TO BE RATHER WEAK THRU MONDAY...SO LOSS OF
MIXING WILL DROP WINDS TO LIGHT QUICKLY FOR OVERNIGHT AND EARLY
MORN HOURS.
LITTLE CHANGE IN THE PATTERN FOR WITH A DRY AIRMASS OVER THE AREA
AND RESULTING IN MOSTLY SUNNY SKIES. MORNING INVERSION WILL BE A
LITTLE STRONGER...BUT WILL AGAIN MIX OUT TO 850 MB OR SO IN THE
AFTERNOON. SPEEDS AT THESE LEVELS ARE AS MUCH AS 35 KT...IN OUR N
MOST ZONES SUNDAY...AND THAT LIKELY WILL REQUIRE A LAKE WIND
ADVISORY TOO.
ANOTHER MINOR SHORTWAVE SUN EVE WITH SOME CLOUDS AND LITTLE OTHER
IMPACT...FOLLOWED BY A VERY SIMILAR DAY MONDAY...WITH LESS WIND
THOUGH.
LONG TERM...MONDAY NIGHT THROUGH SATURDAY
THE MODELS STILL ARE SOMEWHAT INCONSISTENT BASED ON THE 00Z AND
12Z RUNS ON THE PREVIOUS DAY. SINCE THEN THE GFS AND EC HAVE COME INTO
BETTER AGREEMENT WITH THE 00Z RUNS. THE PERIOD BEGINS ON TUESDAY
WITH A S/W RIDGE EXITING THE REGION AND TUESDAY SEEMS TO BE THE
LAST DAY WITH ABOVE NORMAL TEMPERATURES BEFORE A COLD FRONT MOVES
IN ON WEDNESDAY. THE GFS SEEMS TO BE SLIGHTLY FASTER THAN THE EC
WITH THE APPROACH OF THE FRONT. POPS WERE PUT IN THE SOUTHWEST
ZONES ON THURSDAY AS IT APPEARS THE DEVELOPING SYSTEM WILL CLIP
THE SOUTHWEST ZONES. HOWEVER...WITH LOW CONFIDENCE ONLY WENT WITH
SLIGHT CHANCE POPS.
AFTER THE PASSAGE OF THE FIRST SYSTEM THE PATTERN BECOMES QUITE
ACTIVE AND AMPLIFIED. THE LOW THAT PASSES THROUGH SOUTHEAST
MONTANA SEEMS TO UNDERGO SOME LEE CYCLOGENESIS AND DEVELOPS INTO
QUITE A STRONG SYSTEM FOR NEXT WEEKEND. MOST LIKELY THE MODELS WILL
MODIFY THIS IN LATER RUNS BUT AT THIS POINT...THIS REMAINS
SOMETHING TO LOOK AFTER. SHALLENBERGER
AVIATION
VFR CONDITIONS WILL CONTINUE THROUGH THE DAY AND INTO TONIGHT.
WINDS WILL BE SOUTHWEST AT AROUND 10 KT AND CONTINUE AROUND AT 10 KT
IN GENERAL THRU SATURDAY AFTERNOON BEFORE DROPPING OFF TO VERY
LIGHT AFTER SUNSET. SOME SCATTERED MID CLOUDS MAY DRIFT IN
THIS AFTERNOON. SHALLENBERGER
CLIMATE
THE HIGH OF 71 DEGREES IN GLASGOW YESTERDAY...NOV 6TH...TIED A
RECORD HIGH FOR THE DATE SET IN 1931. THERE HAVE ONLY BEEN 6 TIMES
IN THE PAST WHERE WARMER TEMPERATURES OCCURRED ANY LATER IN THE
SEASON. NUMEROUS LOCATIONS IN NE MT REACHED THE 70S YESTERDAY. THE
75 DEGREES HIGHS RECORDED AT WINNNET...TERRY...AND PINE HILL RAWS
WERE THE WARMEST. RECORD HIGHS FOR THE DATE FROM COOPERATIVE
STATIONS WERE SET AT GLENDIVE WATER PLANT...74 DEGREES...BREAKING THE
PREVIOUS RECORD FOR NOV 6TH OF 73 IN 1903. BREDETTE HAD A HIGH OF
70 DEGREES...BREAKING THE PREVIOUS RECORD OF 69 IN 1954. SIMONSEN
GLASGOW WATCHES/WARNINGS/ADVISORIES
NONE.
WEATHER.GOV/GLASGOW
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page