000 FXUS65 KTFX 100841 AFDTFX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 241 AM MDT MON APR 10 2006 .DISCUSSION... TODAY AND TONIGHT...AN UPPER LEVEL SHORT WAVE TROUGH WILL PASS THROUGH THE REGION. MEANWHILE...A DEVELOPING SURFACE LOW OVER NORTHEASTERN WYOMING WILL PUSH INTO THE DAKOTAS BY THIS EVENING. A BAND OF PRECIPITATION WILL DEVELOP BEHIND THE SURFACE LOW ACROSS MUCH OF CENTRAL AND SOUTHWEST MONTANA. HIGH CHANCE TO LIKELY POPS WERE MAINTAINED OVER MOST AREAS. WINTER WEATHER HIGHLIGHTS ARE NOT NEEDED DUE TO RATHER HIGH SNOW LEVELS AND EXPECTED SNOW AMOUNTS. THE PRECIPITATION WILL THEN QUICKLY END THIS EVENING AS THE LOW PRESSURE SYSTEM PULLS OFF TO THE NORTHEAST. TEMPERATURES TODAY AND TONIGHT WILL BE NEAR NORMAL. TUESDAY THROUGH WEDNESDAY...THE UPPER LEVEL FLOW WILL BECOME MORE WESTERLY. A WEAK UPPER LEVEL SHORT WAVE TROUGH MAY BE ENOUGH FOR A FEW SHOWERS ON TUESDAY. OTHERWISE...SHOWER ACTIVITY WILL MAINLY BE CONFINED TO THE MOUNTAINS. TEMPERATURES WILL WARM THROUGH THE PERIOD WITH DOWNSLOPE FLOW DEVELOPING. WEDNESDAY LOOKS RATHER WINDY ACROSS THE PLAINS. SCHAUMANN WEDNESDAY NIGHT THROUGH SATURDAY NIGHT....A FLAT UPPER LEVEL HIGH PRESSURE RIDGE WILL BE OVER THE ZONES WEDNESDAY NIGHT. THE AIRMASS WILL BE QUITE MOIST WEST OF THE DIVIDE AND THE WESTERN MOUNTAINS MAY REMAIN SLIGHTLY UNSTABLE THROUGH THE NIGHT. AN UPPER LEVEL DISTURBANCE MOVING ACROSS THE PACIFIC NORTHWEST WILL CROSS THE ROCKIES BY THURSDAY MORNING. THIS WILL BRING A CHANCE OF SHOWERS TO THE AREA...BUT SHOULD MOVE RAPIDLY THROUGH THE AREA WITH WEAK HIGH PRESSURE AGAIN BUILDING ALOFT BY THE AFTERNOON. THIS HIGH PRESSURE RIDGE WILL MOVE EAST OF THE ZONES DURING THE DAY FRIDAY...AN UPPER LEVEL LOW PRESSURE TROF MOVES OVER THE WEST COAST...AND MOIST SOUTHWEST FLOW ALOFT WILL BEGIN TO AFFECT THE AREA. THIS AIRMASS WILL BECOMES UNSTABLE OVER THE SOUTHWEST ZONES AND WESTERN MOUNTAINS. BY SATURDAY...A LOW PRESSURE SHORTWAVE MOVES OVER THE ZONES. THIS WILL KEEP THE AIRMASS UNSTABLE AT LEAST THROUGH THE EVENING. TEMPERATURES WILL REMAIN ABOVE NORMALS THROUGH THE PERIOD. ZELZER SUNDAY AND MONDAY...EXTENDED MODELS CONTINUE TO AGREE WITH A MOIST SOUTHWEST FLOW ALOFT. THE MOUNTAINS AND THE CENTRAL PLAINS WILL HAVE A CHANCE FOR SCATTERED PRECIPITATION THROUGH THE PERIOD. TEMPERATURES SHOULD BE CLOSE TO SEASONAL. SAUCIER && .AVIATION... UPDATED 0500Z. UPPER LEVEL DISTURBANCE TO MOVE OVER THE SOUTHWEST TONIGHT AND THROUGH CENTRAL MONTANA MONDAY FOR MOSTLY CLOUDY SKIES AND AN INCREASING CHANCE OF PRECIPITATION. VFR CONDITIONS EXPECTED EXCEPT FOR MVFR CEILINGS AND VISIBILITIES IN SHOWERS. ANY BREAKS IN THE CLOUDS WILL ALLOW ENOUGH HEATING MONDAY AFTERNOON FOR A SLIGHT CHANCE OF THUNDERSTORMS MAINLY OVER THE SOUTHERN PORTIONS OF THE AREA. RAIN TONIGHT COULD BE MIXED WITH SNOW ABOVE 5500 FEET. SURFACE LOW TO MOVE UP AND OVER SOUTHERN PORTION OF STATE MONDAY AFTERNOON AND EVENING. CAMP && .HYDROLOGY... RIVERS AND STREAMS ARE AT FAIRLY STEADY LEVELS ACROSS CENTRAL AND SOUTHWEST MONTANA. A STORM SYSTEM WILL BRING MODERATE AMOUNTS OF RAIN AND MOUNTAIN SNOW TO SOUTHWEST MONTANA AS WELL AS EASTERN PORTIONS OF CENTRAL MONTANA TODAY. RIVERS AND STREAMS MAY SHOW SOME RISES THROUGH THE MIDDLE OF THIS WEEK DUE TO RUNOFF AND SNOWMELT. NO MAJOR HYDRO ISSUES ARE EXPECTED IN THE SHORT TERM. && .PRELIMINARY POINT TEMPS/POPS... GTF 53 34 59 35 / 60 20 20 0 CTB 53 32 56 33 / 40 20 20 0 HLN 56 35 59 35 / 60 20 20 0 BZN 53 29 57 31 / 80 20 20 10 WEY 41 17 43 19 / 70 30 30 20 DLN 51 30 53 31 / 60 20 20 10 HVR 57 35 62 36 / 60 30 20 0 LWT 51 32 58 32 / 60 20 20 0 && .TFX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SCHAUMANN LONG TERM...ZELZER/SAUCIER AVIATION...ZELZER WEATHER.GOV/GREATFALLS