721 FXUS65 KTFX 101743 AFDTFX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 1142 AM MDT SUN JUN 10 2012 UPDATED AVIATION DISCUSSION .UPDATE... HAVE INCREASED POPS QPF AND WEATHER TO BETTER MESH WITH CURRENT RADAR REFLECTIVITY RETURNS AND GROUND TRUTH DATA FROM THE AREA. WIDESPREAD PRECIPITATION HAS BEEN A LITTLE SLOWER AND LIGHTER THAN MODEL RUNS HAVE PREVIOUSLY SUGGESTED DUE TO DRY NATURE OF THE WESTWARD CHINOOK WINDS. HOWEVER THE MOISTURE DOES SEEM TO FINALLY BE PUNCHING THROUGH THIS DRY LAYER AND CREATE MEASURABLE AMOUNTS OF PRECIPITATION ACROSS THE AREA. THIS WIDESPREAD STRATIFORM RAIN APPEARS TO BE THE DOMINANT PLAYER FOR THE NEXT FEW HOURS AS MOISTURE CONTINUES TO BE ADVECTED IN FROM THE NORTH IN THIS CLASSIC WRAP AROUND PRECIPITATION PATTERN. THE LOW IS STILL FORECASTED TO SLOWLY MOVE TO THE NORTH EAST AND WILL BRING THE THE PRECIPITATION WITH IT...WITH A TAPERING OFF OF THE PRECIPITATION EXPECTED IN THE LATE AFTERNOON AND EARLY EVENING ACROSS MOST OF CENTRAL AND NORTH CENTRAL MONTANA. SUK && .AVIATION... UPDATED 1742Z. CURRENT RADAR INDICATES WIDESPREAD PRECIPITATION FOR MOST OF CENTRAL AND NORTHERN MONTANA. TERMINALS CAN CONTINUE EXPECT LOW CLOUDS...RAIN... MOUNTAIN SNOW RESULTING IN IFR CONDITIONS. EXPECT MOUNTAIN OBSCURATIONS THROUGH SUNDAY EVENING. CONDITIONS WILL IMPROVE SLOWLY OVERNIGHT FROM WEST TO EAST...AS THE UPPER LEVEL TROF SLOWLY EXITS THE REGION. MERCER && .PREV DISCUSSION... /ISSUED 545 AM MDT SUN JUN 10 2012/ TODAY THROUGH TUESDAY...CIRCULATION AROUND A CLOSED UPPER LOW LOCATED OVER NORTHEAST MONTANA IS SPREADING LOW CLOUDS AND RAIN OVER THE AREA. CLOUD TOPS ARE COOLING AND INCREASING OVER THE NORTHWEST PORTION OF THE COUNTY WARNING. CLOUDS AND RAIN WILL CONTINUE TO SPREAD SOUTH AND EAST OVER THE AREA THIS MORNING. SNOW LEVELS ALONG THE ROCKY MOUNTAIN FRONT WILL DROP TO AROUND 5000 FEET AND A WINTER WEATHER ADVISORY FOR SNOW HAS BEEN ISSUED FOR THAT AREA. LIKEWISE...SNOW LEVELS NEAR 5500 FEET OVER THE BELTS HAVE PROMPTED WINTER WEATHER HIGHLIGHTS FOR SNOW. LOWER ELEVATIONS WILL SEE RAIN WITH SOUTHWEST MONTANA EXPERIENCING SCATTERED SHOWERS. SURFACE PRESSURE GRADIENTS WILL CONTINUE TO TIGHTEN ACROSS THE PLAINS THIS MORNING WITH GUSTY WEST TO NORTHWEST WINDS DEVELOPING. QUESTION TO CONSIDER IS WHETHER THE DOWNSLOPE WEST WINDS WILL BE STRONG ENOUGH INHIBIT THE RAIN OVER THE PLAINS. AT THIS POINT...IT APPEARS THE UPPER LEVEL DYNAMICS OF THE CIRCULATION ALOFT WILL REMAIN STRONG ENOUGH TO OVERCOME THE DOWNSLOPE EFFECTS. THE UPPER LOW MOVES EAST OVERNIGHT AND THE AREA COMES UNDER THE INFLUENCE OF UNSTABLE NORTHWEST FLOW ALOFT. ISOLATED SHOWERS WILL DEVELOP AGAIN ON MONDAY. ZONAL FLOW ALOFT ON TUESDAY WILL BRING SOME DRYING...ALTHOUGH WEAK SHORTWAVE ENERGY MOVING WITHIN THIS FLOW WILL BRING ISOLATED TO SCATTERED THUNDERSTORMS ON TUESDAY. TEMPERATURES WILL BE BELOW SEASONAL AVERAGES TODAY BEFORE BEGINNING A SLOW WARMING TREND MONDAY. EMANUEL TUESDAY NIGHT THROUGH SUNDAY...AN FAST MOVING UPPER LEVEL DISTURBANCE WILL MOVE THROUGH THE REGION WEDNESDAY/WEDNESDAY EVENING RESULTING IN A FEW SHOWERS/THUNDERSTORMS OVER THE REGION. OTHERWISE...A WESTERLY FLOW ALOFT IS EXPECTED MAINLY FOR THURSDAY AND FRIDAY. THIS FLOW ALOFT WILL RESULT IN MOSTLY DRY CONDITIONS AT LOWER ELEVATIONS...WHILE THE CHANCES FOR A SCATTERED MOUNTAIN SHOWER/THUNDERSTORM ACTIVITY CONTINUES. HOWEVER...ANY PRECIP ACTIVITY SHOULD BE FAIRLY ISOLATED FOR THE LATER PORTIONS OF NEXT WEEK. BY SATURDAY AND INTO SUNDAY...A DEEPER UPPER LEVEL TROF OF LOW PRESSURE WILL BEGIN TO PUSH SOUTHWARD FROM CENTRAL CANADA INTO NORTH CENTRAL MONTANA. AS A RESULT...EXPECT COOLER AIR AND A SLIGHTLY BETTER CHANCE FOR SHOWERS OVER MUCH OF THE REGION BY SUNDAY. AT THIS TIME...THIS SYSTEM FOR NEXT WEEKEND DOES NOT LOOK TO BE A MAJOR STORM. IN TERMS OF TEMPERATURES...EXPECT AFTERNOON TEMPERATURES TO BE NEAR/SLIGHTLY ABOVE NORMAL FOR WEDNESDAY THROUGH THURSDAY...BUT THEN GRADUALLY COOL DOWN A FEW DEGREES FOR NEXT FRIDAY THRU SUNDAY. BRUSDA && .PRELIMINARY POINT TEMPS/POPS... GTF 57 42 72 45 / 100 40 20 10 CTB 56 41 70 45 / 100 50 20 10 HLN 56 41 72 46 / 90 40 20 10 BZN 54 35 71 41 / 70 30 20 10 WEY 48 29 63 35 / 60 30 20 10 DLN 58 34 70 41 / 50 20 20 10 HVR 58 45 73 47 / 90 60 20 10 LWT 51 40 68 44 / 100 60 20 10 && .TFX WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 6 PM MDT THIS EVENING FOR ELEVATIONS ABOVE 5000 FEET FOR CENTRAL AND SOUTHERN LEWIS AND CLARK...NORTHERN ROCKY MOUNTAIN FRONT...SOUTHERN ROCKY MOUNTAIN FRONT. WINTER WEATHER ADVISORY UNTIL 6 PM MDT THIS EVENING FOR ELEVATIONS ABOVE 5500 FEET FOR CASCADE...JUDITH BASIN...MEAGHER. && $$ SHORT TERM...SUK LONG TERM...BRUSDA AVIATION...BRUSDA WEATHER.GOV/GREATFALLS