000 FXUS65 KGGW 051543 AFDGGW AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GLASGOW MT 943 AM MDT FRI SEP 5 2008 .SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SUNDAY... ONLY MINOR UPDATE TO CLOUD COVER FOR TODAY. ALSO FOR END OF PATCHY FOG. SHORTWAVE ENERGY PUSHING MOISTURE INTO CENTRAL MONTANA WITH CLOUDS NUDGING TOWARD EASTERN MONTANA. AIRMASS NOT AS UNSTABLE AS YESTERDAY SO AFTERNOON SHOWERS ARE LESS LIKELY THIS AFTERNOON THAN YESTERDAY. ALSO MORE SUNSHINE...SO EXPECT SLIGHTLY WARMER TEMPERATURES AS WELL. EBERT PREVIOUS SHORT TERM DISCUSSION...NOT MUCH CHANGE IN THE LONGWAVE PATTERN THRU THE WEEKEND...WITH UPPER RIDGING OFF THE W COAST...UPPER TROUGHING OVER THE MIDWEST. NE MT IS ON THE BACKSIDE OF TROUGH IN NW FLOW...WITH THE JETSTREAM REMAINING STRONGER AND FARTHER S THAN USUAL FOR EARLY SEP. THIS MORN...SOME LOCATIONS SHOW OBS THAT ARE NEARLY SATURATED. THIS NOT AS EXTENSIVE AS YESTERDAY THOUGH. RUC SHOWS 95 PCT RH ACROSS ROUGHLY OUR NE QUARTER AT 12Z. WILL COMBINE THIS WITH THE OBS THAT HAVE BEEN REPORTING TEMP/DEW POINT SPREADS OF 0-2F AT 3 AM TO ADD PATCHY EARLY MORN FOG MENTION. THIS WILL BE IN LOWER MILK...MISSOURI...AND BIG MUDDY RIVER VALLEYS. OTHERWISE... GENERALLY CLEAR SKIES EARLY THIS MORN...BUT IR SATELLITE CHANNEL SHOWS A RATHER LARGE AREA OF MID-LEVEL OVERCAST IN AB AND NC/NW MT THAT WILL BE MOVING ACROSS OUR N THIS MORN. NO PRECIP EXPECTED FROM IT. OTHERWISE MORE SUNSHINE WILL ALLOW A FEW DEGREES WARMING OVER YESTERDAY. AIRMASS SLIGHTLY DRIER AND SLIGHTLY LESS UNSTABLE FOR THE AFTERNOON WITHOUT ANY SHORTWAVES. THIS SHOULD LIMIT SHOWER DEVELOPMENT TO LESS THAN YESTERDAY...BUT THERE WILL BE A FEW WEAK CELLS...MAINLY E. WILL GO WITH POPS LOW ENOUGH THAT THEY WON`T SHOW AS WORDING IN TEXT PRODUCTS. MODELS CONTINUE TO BRING A MODERATE SHORTWAVE FROM THE NW ACROSS THE AREA LATE TONIGHT AND SAT FOR SCATTERED SHOWERS. ALL MODELS SHOW A FAIR AREA OF QPF. THE SYSTEM DOESN`T APPEAR ALL THAT WELL ORGANIZED...SO WILL KEEP POPS IN SCATTERED CATEGORY...BUT KEEPING IN MIND ALSO THAT TYPICALLY THESE SYSTEMS FROM THE NW ARE OFTEN UNDERFORECAST FOR POPS. WITH 850 MB WINDS TO 20KT OR SO WITH WEAK COOL ADVECTION IN THE AFTERNOON...WILL BE NEAR LAKE WIND ADVISORY CRITERIA SAT. SKIES CLEAR ACROSS OUR N SAT NIGHT. THICKNESSES DROP TO AROUND 543 DM AND 850 TEMPS TO 5C. THIS IS AT LEAST AS LOW AS THE PREVIOUS FEW COOL NIGHTS. WITH SURFACE HIGH OVER AREA AND DEW POINTS LOWER THAN LATELY...WOULD EXPECT WIDESPREAD 30S FOR LOWS...SOME TO AROUND FREEZING IN THE TYPICAL COLDEST POCKETS. MEANWHILE.. INCREASING CLOUDS IN OUR S. MODELS VARY QUITE A BIT ON INTENSITY...BUT ALL HAVE A SHORTWAVE MOVE SE ALONG THE JETSTREAM THRU THE MIDDLE OF THE STATE LATE SAT NIGHT AND SUN. THESE OFTEN DO AFFECT OUR SW...BUT SELDOM ELSEWHERE AS FAR AS PRECIP GOES. WILL GO WITH A CHANCE OF RAIN SUN IN OUR SW. PREFER TO GO A LITTLE BELOW MOS ALL AREAS SUN AS WELL. SIMONSEN .LONG TERM...SUNDAY NIGHT THROUGH FRIDAY... NORTHWEST FLOW ALOFT WILL CONTINUE OVER THE FORECAST AREA MOST OF THE TIME THROUGH THE PERIOD. LOOK FOR DRY WEATHER AND A WARMING TREND WITH A SURFACE HIGH ON MONDAY AND A SHORTWAVE UPPER RIDGE ON TUESDAY. MODELS HAVE HAD SOME DIFFERENCES ON TRACKING A MIDWEEK SHORTWAVE TROUGH AND COLD FRONT. 00Z GFS...00Z CANADIAN AND 12Z ECMWF HAD THE FRONT AND SHORTWAVE AFFECTING THE FORECAST AREA ON WEDNESDAY. 00Z ECMWF HAS SLOWED IT DOWN. THE LAST 3 RUNS OF THE GFS HAVE HAD THE MAIN PART OF THE WAVE AFFECTING NE MONTANA EITHER WEDNESDAY OR WEDNESDAY NIGHT WITH THE COLD FRONT FORECASTED FOR WEDNESDAY FOR SEVERAL RUNS. WILL MAINTAIN A WED FRONTAL PASSAGE AND MENTION A SLIGHT CHANCE OF THUNDERSTORMS ON WED AND SHOWERS WED NIGHT. NORTHWEST FLOW ALOFT WILL PREVAIL AFTER THE TROUGH EXITS WITH MAINLY DRY WEATHER. FORRESTER && .AVIATION... VFR CONDITIONS ARE EXPECTED TO PREVAIL TODAY INTO THIS EVENING. BROKEN CUMULUS AROUND 4K OR 5K FT AGL IS EXPECTED THIS AFTERNOON INTO EARLY EVENING. NORTHWEST WIND WILL BE AROUND 10 KT TODAY. LOOK FOR EITHER MID LEVEL OR LOW VFR CEILINGS TO PREVAIL LATER TONIGHT WITH A CHANCE OF RAIN THAT WILL CONTINUE THROUGH SATURDAY. FRANSEN && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && $$ WEATHER.GOV/GLASGOW