001 FXUS65 KBYZ 140940 AFDBYZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BILLINGS MT 340 AM MDT THU JUN 14 2012 .SHORT TERM...VALID FOR TDY AND FRI... UPPER TROUGH OF LOW PRESSURE MOVED ACROSS EASTERN MONTANA OVERNIGHT AND PRODUCED ISOLATED SHOWERS AND THUNDERSTORMS OVER OUR EASTERN ZONES. PRECIPITATION WAS BEING AIDED BY STRONG 700 TO 500 MB BAND OF FRONTOGENESIS STATIONARY OVER THE SOUTHEAST. ISOLATED THUNDERSTORMS WERE STILL DEVELOPING AS OF 930Z THIS MORNING AND WILL KEEP SLIGHT CHANCE GOING THROUGH 15Z THIS MORNING. WEAK RIDGING ALOFT WILL DEVELOP OVER THE FORECAST AREA TODAY AND WILL BRING DRY WEATHER WHICH WILL LAST OVERNIGHT. FLOW ALOFT WILL QUICKLY BACK TO THE SOUTHWEST ON FRIDAY AS ANOTHER TROUGH OF LOW PRESSURE MOVES IN FROM THE NORTHERN ROCKIES. UPPER LOW WILL TRACK ALONG THE CANADIAN/MONTANA BORDER FRIDAY AND DRAG A COLD FRONT ACROSS THE AREA. EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP FROM LIVINGSTON WEST TO BILLINGS TOMORROW WITH A BETTER CHANCE OF STRONG THUNDERSTORMS DEVELOPING OVER SOUTHEAST MONTANA DURING THE AFTERNOON AND EVENING. ADVANCING UPPER TROUGH WILL SET UP A LOW LEVEL 30KT JET OVER OUR EASTERN ZONES AND ALLOW LOW LEVEL MOISTURE ADVECTION. 06Z WRF INDICATING DECENT CAPE VALUES OF AROUND 1500 J/KG DURING THE AFTERNOON AND EVENING HOURS FOR CUSTER...POWDER RIVER...FALLON AND CARTER COUNTIES. THE ONLY FLY IN THE OINTMENT IS SEVERE WEATHER POTENTIAL OVER THE CENTRAL PLAINS TODAY WHICH MAY HAMPER A RETURN FLOW OF MOISTURE INTO THE NORTHERN PLAINS. WILL HOLD OFF ON MENTIONING SEVERE WEATHER FOR TOMORROW AFTERNOON AND EVENING IN THE SOUTHEAST BUT WILL ISSUE AN HWO AND WEATHER STORY TO INCREASE AWARENESS OF POTENTIAL FOR STRONG THUNDERSTORMS. TEMPERATURES TODAY AND FRIDAY WILL BE NEAR OR SLIGHTLY ABOVE SEASONAL NORMALS. RICHMOND .LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED... OUTSIDE OF A LOW PROBABILITY OF CONVECTION ON SUN...WE EXPECT THIS WEEKEND TO BE DRY AND WARM. THAT IS PREDICATED ON RELATIVELY SMALL SPREAD AMONG 00 UTC MODEL SOLUTIONS WITH RESPECT TO WEST-NORTHWEST 500-HPA FLOW FOR THE WEEKEND. THE PATTERN IS EXPECTED TO DELIVER A WEAK SHORT WAVE ON SUN...BUT IN MANY WAYS THAT FEATURE LOOKS AS IF IT WILL ACT LIKE THE ONE WE EXPERIENCED YESTERDAY...WHICH SUGGESTS THAT DRY/WESTERLY LOW-LEVEL FLOW COULD REALLY HINDER CONVECTION. A WELL-MIXED BOUNDARY LAYER IS EXPECTED BOTH SAT AND SUN...AND BASED ON THAT WE ACTUALLY INCREASED FORECAST HIGHS BY SEVERAL DEGREES F. A BROAD 500-HPA TROUGH IS EXPECTED TO TAKE SHAPE ACROSS THE REGION FROM MON INTO WED...BUT THE LAST COUPLE MODEL CYCLES HAVE PROVIDED SOME NOTABLE DIFFERENCES IN THE DETAILS OF THIS EVOLUTION. WE FELT THAT MAINTAINING CONTINUITY IN OUR GRIDDED FORECAST WAS THE WAY TO GO DURING THIS PERIOD FOR NOW. FORECAST HIGHS ARE ACTUALLY SEVERAL DEGREES F WARMER THAN THE 00 UTC MULTI-MODEL CONSENSUS ACROSS MUCH OF THE AREA. HOWEVER...THAT IS PROBABLY NOT A BAD PLACE TO BE WHEN CONSIDERING THE RECENT COOL BIASES DISPLAYED BY MOST GUIDANCE WITH OUR DRY AMBIENT CONDITIONS. SCHULTZ && .AVIATION... A SMALL CHANCE OF A SHOWER OR THUNDERSTORM EXISTS IN SOUTHEASTERN MT EARLY THIS MORNING. HOWEVER...VFR CONDITIONS WILL PREVAIL TODAY OVER THE WHOLE AREA THANKS TO HIGH PRESSURE. EXPECT WEST-NORTHWEST WIND GUSTS TO AROUND 25 KT...MAINLY OVER SOUTHEASTERN MT IN PLACES LIKE KMLS AND KBHK. VFR CONDITIONS WILL ALSO PREVAIL TONIGHT...BUT THERE WILL BE A CHANCE OF THUNDERSTORMS OVER SOUTHEASTERN MT AFTER 06 UTC. SCHULTZ && .PRELIMINARY POINT TEMP/POPS... TDY FRI SAT SUN MON TUE WED ------------------------------------------------------- BIL 077 051/076 050/082 060/084 055/075 052/073 051/075 0/U 13/T 21/B 12/T 32/T 23/T 33/T LVM 075 040/073 040/079 050/078 048/072 043/070 043/072 0/U 13/T 21/B 12/T 32/T 24/T 33/T HDN 081 049/080 051/082 055/085 056/078 053/076 050/077 0/U 13/T 31/B 12/T 32/T 23/T 23/T MLS 079 055/080 054/082 062/084 058/076 055/075 053/077 2/T 14/T 41/B 12/T 33/T 23/T 23/T 4BQ 078 053/081 054/079 057/085 057/075 054/077 051/076 2/T 24/T 61/B 12/T 32/T 23/T 23/T BHK 078 055/079 055/076 055/083 056/074 053/074 051/073 2/T 25/T 61/B 12/T 33/T 23/T 33/T SHR 076 048/077 049/079 053/083 053/073 049/071 047/074 0/U 23/T 41/B 12/T 32/T 23/T 23/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS