961 FXUS65 KBYZ 030126 AFDBYZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BILLINGS MT 726 PM MDT FRI MAY 2 2014 .UPDATE... UPDATED THE FORECAST TO CUT BACK CONSIDERABLY ON PRECIP...IN TERMS OF BOTH CHANCES AND AMOUNTS...ACROSS MUCH OF THE SOUTHWESTERN 2/3RDS OF THE REGION TONIGHT INTO SATURDAY MORNING. THERE JUST DOES NOT SEEM TO BE MUCH SUPPORT FOR THE HIGHER PRECIP CHANCES OR FOR THUNDERSTORMS THROUGH MUCH OF TONIGHT. SATELLITE IMAGERY SHOWS UPPER LEVEL RIDGING IN FROM THE WEST THIS EVENING. RADAR ALSO SHOWS THE AREA OF SHOWERS EDGING SLIGHTLY TO THE EAST...MAINLY CONFINED TO THE FOUR EASTERN COUNTIES OF THE CWA FOR THE TIME BEING. ANOTHER WEAK SURGE OF COOL AIR WILL INCREASE FRONTOGENESIS LATE TONIGHT INTO EARLY SATURDAY...WHICH MAY ALLOW THE AREA OF SHOWERS TO EXPAND WESTWARD A BIT AND WILL HELP PUSH A DECK OF LOW CLOUDS WESTWARD ACROSS THE AREA. THIS AREA OF LOW CLOUDS WILL PUSH WEST OF BILLINGS DURING THE EARLY MORNING HOURS...BUT WILL HAVE A MORE DIFFICULT TIME REACHING LIVINGSTON. STC && .SHORT TERM...VALID FOR SAT AND SUN... BACKDOOR FRONT HAS WORKED ITS WAY THROUGH THE EASTERN 2/3RDS OF THE FORECAST AREA BUT HAS YET TO MAKE IT TO LIVINGSTON. WEST WINDS AHEAD OF THE FRONT ALONG WITH MUCH LOWER DEWPOINTS HAVE ALLOWED TEMPERATURES TO WARM INTO THE LOWER 70S ACROSS OUR FAR WESTERN LOCATIONS. AREA OF LOW STRATUS CURRENTLY STRETCHES ACROSS NORTH CENTRAL MONTANA TO SOUTHEAST MONTANA THIS AFTERNOON WITH SOME LIGHT RAIN BEING REPORTED AT MILES CITY AND BAKER AT TIMES. THIS STRATUS DECK WILL SLOWLY WORK ITS WAY SOUTH AND WEST THIS EVENING AND DURING THE OVERNIGHT HOURS. AREAS OF MAINLY LIGHT SHOWERS BEHIND THE FRONT WILL SLOWLY SHIFT SOUTHWEST AS WELL BRINGING INCREASING CHANCES FOR SHOWERS THROUGH THIS EVENING AND OVERNIGHT FROM BILLINGS WESTWARD. TEMPERATURES WILL BE COOLER TONIGHT THAN LAST NIGHT WITH MID 30S TO LOWER 40S COMMON. UNSETTLED WEATHER WILL CONTINUE SATURDAY AND SUNDAY AS THE FRONT BECOMES STATIONARY ALONG THE BEARTOOTH/ABSAROKA/BIG HORN FOOTHILLS AREA. A MOIST EASTERLY SURFACE FLOW WILL PREVAIL THROUGH THE PERIOD WITH BRISK EASTERLY WINDS AT TIMES. A BAROCLINIC ZONE AND FRONTOGENESIS BAND WILL BE SITUATED ACROSS OUR CENTRAL LOCATIONS BRINGING HIGH CHANCE TO LIKELY POPS. PRECIP IS EXPECTED TO BE IN THE SHOWER FORM AND NOT AN ALL DAY STEADY RAIN. A SURFACE LOW DEVELOPS ACROSS NORTHERN WYOMING SUNDAY RESULTING IN BETTER CHANCES FOR SHOWERS. MODELS CURRENT PLACEMENT OF THE LOW KEEPS THE BEST CHANCES OF SHOWERS ACROSS OUR NORTHERN ZONES...AS WELL AS NORTH CENTRAL AND NORTHEAST MONTANA. INSTABILITY IS PRETTY MINIMAL FOR THUNDERSTORM POTENTIAL BUT CAN'T RULE OUT AN ISOLATED AFTERNOON/EVENING THUNDERSTORM EACH DAY. HIGHS SATURDAY WILL BE ABOUT 10 TO 15 COOLERS THAN TODAY WITH READINGS IN THE 50S. TEMPERATURES ARE EXPECTED TO REBOUND BACK INTO THE 60S FOR SUNDAY. HOOLEY .LONG TERM...VALID FOR MON...TUE...WED...THU...FRI... CONFIDENCE CONTINUES TO INCREASE IN A GENERALLY COOL AND UNSETTLED PATTERN FOR NEXT WEEK AS THE MODELS CONTINUED TO AGREE ON A SPLITTING PACIFIC TROUGH AFFECTING THE WESTERN U.S.. THUS HAVE RAISED POPS FOR MOST OF THE PERIOD. WEAK RIDGING WILL BEGIN TO GIVE WAY TO SW FLOW ON MON AS THE TROUGH ROTATES INTO THE PACIFIC NW. LOW-LEVEL FLOW WILL TURN N AND E AS A SURFACE LOW MOVES INTO E WY AND SCATTERED SHOWERS WITH A FEW THUNDERSTORMS WILL DEVELOP OVER THE AREA. UNDER GOOD MIXING...MON LOOKS TO BE THE WARMEST DAY OF THE EXTENDED WITH HIGHS IN THE 60S TO LOWER 70S. SHOWERS WILL BECOME MORE WIDESPREAD MON NIGHT AS A COLD FRONT MOVES THROUGH THE AREA AND SW FLOW INCREASES ALOFT. AN INVERTED TROUGH WILL ALSO DEVELOP OVER THE AREA. COOL NE UPSLOPE FLOW WILL PREVAIL OVER THE REGION ON TUE AND TUE NIGHT AS THE SPLITTING TROUGH MOVES E. SHOWERS WILL BE LIKELY ACROSS THE AREA. HIGHS WILL BE IN THE 50S TO LOWER 60S ON TUE. THE TROUGH WILL PUSH SLOWLY E WED AND WED NIGHT AND COOLER AIR WILL FILTER INTO THE AREA FROM THE N. NE FLOW WILL SUPPORT GOOD PRECIPITATION CHANCES ON WED BEFORE THE FLOW STARTS TO DRY OUT WED NIGHT. WED WILL BE THE COOLEST DAY OF THE PERIOD WITH HIGHS IN THE LOWER TO MID 50S. HEIGHTS WILL RISE THU THROUGH FRI...ALTHOUGH THE AREA WILL REMAIN UNDER CYCLONIC FLOW. CHANCES FOR PRECIPITATION WILL DECREASE DURING THIS TIME AND THERE WILL BE A WARMING TREND. ARTHUR && .AVIATION... AN AREA OF SHOWERS WILL PERSIST THIS EVENING OVER FAR NORTHEAST SECTIONS OF THE FORECAST AREA...GENERALLY EAST OF A MILES CITY TO ALZADA LINE. A REINFORCEMENT OF A STATIONARY COLD FRONT WEST OF BILLINGS WILL START TO DRAG THIS PRECIPITATION AREA WESTWARD OVERNIGHT INTO TOMORROW MORNING. AT THIS TIME PRECIPITATION CHANCES OVERNIGHT LOOK TO STAY EAST OF A ROUNDUP TO ASHLAND LINE. HOWEVER MODELS HAVE INCREASED CHANCES OF STRATUS AND POSSIBLY LOCALIZED FOG DEVELOPMENT FOR AREAS FURTHER WEST INCLUDING KBIL AND KSHR TAF LOCATIONS AFTER 10Z. WESTERLY WINDS THIS EVENING WILL BE GUSTY WEST OF THE STATIONARY FRONT INCLUDING IN AND AROUND KLVM...BUT SHOULD DIMINISH OVERNIGHT AS EASTERLY WINDS BUILD INTO THE FOOTHILLS. CHAMBERS && .PRELIMINARY POINT TEMP/POPS... SAT SUN MON TUE WED THU FRI ----------------------------------------------------------- BIL 042/057 041/063 043/070 043/060 042/054 038/061 042/063 13/W 33/T 44/T 66/W 65/W 43/W 22/W LVM 039/061 038/062 039/066 038/057 037/051 032/060 038/060 13/T 46/T 54/T 67/W 66/W 55/W 33/W HDN 039/059 036/068 041/075 040/063 038/055 036/063 038/065 13/W 32/T 44/T 56/W 65/W 23/W 22/W MLS 038/055 040/064 041/071 045/063 042/055 039/062 043/064 54/W 64/T 44/T 67/W 65/W 43/W 22/W 4BQ 039/057 037/067 042/073 043/064 040/053 038/062 039/064 23/T 32/T 33/T 57/W 66/W 44/W 23/W BHK 036/052 037/059 040/069 043/060 040/052 037/060 038/061 54/W 74/T 43/T 67/W 65/W 43/W 22/W SHR 039/065 038/069 040/071 040/060 038/051 034/060 038/061 13/T 22/T 23/T 46/W 66/W 43/W 22/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS