774 FXUS65 KTFX 181107 AFDTFX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 407 AM MST THU FEB 18 2010 .DISCUSSION... TODAY THROUGH SATURDAY...NORTHERLY FLOW ALOFT CONTINUES TO BRING SHORT WAVE ENERGY DOWN FROM CANADA. NEXT SHORT WAVE HAS SLIPPED THROUGH CUT BANK AT THIS TIME AND WILL CONTINUE TO PUSH SOUTH THROUGH THE MORNING HOURS. LIGHT SNOW IS EXPECTED WITH THIS FEATURE WITH AMOUNTS GENERALLY AROUND AN INCH. SNOW SHOULD TAPER OFF BY EARLY AFTERNOON. THE CYCLONIC FLOW PATTERN ALOFT WILL PERSIST INTO THE WEEKEND WITH ISOLATED TO SCATTERED LIGHT SNOW REMAINING A POSSIBILITY FRIDAY AND AGAIN ON SATURDAY. LITTLE ACCUMULATION IS EXPECTED. TEMPERATURES WILL COOL A BIT THE NEXT FEW DAYS WITH AFTERNOON READINGS REMAINING BELOW SEASONAL AVERAGES. EMANUEL SATURDAY NIGHT THROUGH TUESDAY NIGHT...00Z RUNS OF GFS AND ECMWF FORECAST MODELS ARE IN GOOD AGREEMENT FOR THIS PERIOD. THE UPPER LEVEL TROUGH OF LOW PRESSURE ORIENTED NORTHEAST TO SOUTHWEST OVER MONTANA WILL MOVE SOUTH OF THE TFX CWA SATURDAY NIGHT. THIS WILL GENERALLY KEEP A CHANCE OF SNOW ONLY OVER SOUTHWEST MONTANA. AN UPPER LEVEL HIGH PRESSURE RIDGE WILL THEN MOVE EAST FROM THE PACIFIC COAST INTO THE ROCKY MOUNTAIN AREA...FOR GENERALLY DRIER AND WARMING CONDITIONS SUNDAY THROUGH TUESDAY. THIS WILL GENERALLY WARM TEMPERATURES BACK TO NEAR NORMAL BY MONDAY. HOWEVER...A WEAK DISTURBANCE WILL MOVE DOWN THE LEADING EDGE OF THE RIDGE AND OVER EASTERN MONTANA ON MONDAY. THIS WILL BRING A SLIGHT CHANCE OF SNOW TO THE EASTERN ZONES OF THE TFX CWA. THE UPPER LEVEL RIDGE WILL BROADEN AS IT SPREADS EAST INTO THE AREA EARLY IN THE WEEK. ANOTHER DISTURBANCE WILL MOVE THROUGH THE RESULTING WESTERLY FLOW ALOFT AND BRING AN INCREASING CHANCE OF MAINLY MOUNTAIN SNOW TO THE AREA TUESDAY NIGHT. COULSTON WEDNESDAY AND THURSDAY...BOTH THE GFS AND ECMWF DEVELOP A WESTERLY FLOW ALOFT OVER THE REGION...WITH A SMALL UPPER LEVEL RIDGE BUILDING OVER THE PACIFIC NORTHWEST. AS A RESULT...PACIFIC AIR WILL MOVE INTO THE REGION...ALLOWING FOR SEASONABLE...TO SLIGHTLY ABOVE NORMAL TEMPERATURES FOR ALL AREAS EXCEPT THE HAVRE AREA...WHERE TEMPERATURES WILL CONTINUE TO REMAIN BELOW NORMAL IN THIS REGION. THERE WILL BE A SMALL CHANCE FOR PRECIPITATION AS WELL...WITH THE GFS BEING A BIT MORE AGGRESSIVE WITH THE PRECIP THAN THE ECMWF IS. THUS WENT MORE WITH CLIMO POPS OVER THE REGION FOR THE MIDDLE PORTION OF NEXT WEEK...BUT WITH BREEZY WEST WINDS ON THURSDAY OVER THE NORTHERN PLAINS...THE PRECIP WAS CONFINED MAINLY TO THE MOUNTAINS FOR THURSDAY. BRUSDA && .AVIATION... UPDATED 0600Z. A SHORTWAVE AND ASSOCIATED SURFACE COLD FRONT CONTINUE TO PUSH SOUTH THROUGH SOUTHERN MONTANA THIS EVENING. EXPECT WIDESPREAD LIGHT SNOW WITH MVFR AND OCCL IFR CONDITIONS THROUGH EARLY THURSDAY MORNING. WIDESPREAD MOUNTAIN OBSCURATION WILL ALSO PERSIST THROUGH THURSDAY MORNING. THERE IS A CHANCE FOR BRIEF PERIODS OF FOG AND LOW STRATUS AS POCKETS OF CLEARING PASS OVER SOME LOCATIONS. LOCATIONS WILL BE DIFFICULT TO IDENTIFY AS THE SHORTWAVE IS NOT VERY ORGANIZED. CONDITIONS ARE EXPECTED TO IMPROVE TOWARDS VFR AS THE DAY WEARS ON. && .PRELIMINARY POINT TEMPS/POPS... GTF 32 16 24 10 / 60 30 20 20 CTB 33 15 25 11 / 60 20 20 20 HLN 31 18 27 15 / 60 20 20 20 BZN 32 12 29 12 / 50 20 20 20 WEY 29 0 27 2 / 30 30 20 30 DLN 32 11 26 9 / 40 20 20 20 HVR 23 10 19 7 / 40 30 20 20 LWT 28 14 22 9 / 60 30 20 20 && .TFX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...EMANUEL LONG TERM...COULSTON/BRUSDA AVIATION...GUSTAFSON WEATHER.GOV/GREATFALLS