000 FXUS63 KBIS 072155 AFDBIS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BISMARCK ND 345 PM CST SAT NOV 7 2009 .SHORT TERM...TONIGHT TROUGH TUESDAY NIGHT... MAIN FORECAST PROBLEM IN THE SHORT TERM IS ISOLATED PRECIPITATION CHANCES TONIGHT AND SUNDAY. OTHERWISE DRY THROUGH THE SHORT TERM PERIOD WITH CONTINUED MILD TEMPERATURES. WILL USE A GENERAL MODEL BLEND. CURRENTLY...SURFACE HIGH PRESSURE FROM NEBRASKA INTO SOUTHERN NORTH DAKOTA...PRODUCING GENERALLY LIGHT WINDS. STRONGER GRADIENT ACROSS THE NORTHERN PERIPHERY OF THE HIGH IS PRODUCING BREEZY CONDITIONS ACROSS THE NORTHERN AND EASTERN CWA. ONLY CLOUDINESS IN THE CWA IS SOME JET INDUCED HIGH LEVEL CLOUDINESS ACROSS THE FAR SOUTH AND SOME MID LEVEL CLOUDINESS PUSHING INTO THE FAR WEST IN AREA OF PVA. TEMPERATURES ACROSS THE AREA ARE COOLER THAN YESTERDAY BUT STILL WELL ABOVE NORMAL. EXPECT CLOUDINESS TO INCREASE...ESPECIALLY ACROSS THE SOUTH TONIGHT AND BY LATE TONIGHT AND SUNDAY THERE WILL BE AN AREA OF ENHANCED LIFT AS A SHORTWAVE TROUGH COMBINES WITH RIGHT ENTRANCE REGION OF THE STRONG UPPER JET...CURRENTLY OVER THE STATE. THE PROBLEM WILL BE A LACK OF LOW AND MID LEVEL MOISTURE. BOTH NAM AND GFS BURF SOUNDINGS INDICATE A DRY ATMOSPHERE BELOW 750 MB. THE GFS...ECMWF AND UKMET DO PRODUCE SOME LIGHT QPF WHILE THE NAM AND GEM ARE DRY. THE 15Z SREF IS SHOWING SOME 20 PERCENT PROBABILITIES OF >.01 INCH ACROSS THE SOUTH CENTRAL. THIS IS A BIT LESS THAN THE 09Z RUN. WILL KEEP SLIGHT CHANCE POPS IN THE FORECAST LATE TONIGHT THROUGH SUNDAY WITH REALLY NO ADJUSTMENT TO PLACEMENT (MAINLY ALONG AND SOUTH OF INTERSTATE 94). PRECIPITATION WILL BE LIQUID THIS EVENING BUT DEPENDING ON HOW QUICK TEMPERATURES DROP OFF...THERE MAY BE SOME FREEZING TEMPERATURES AFTER MIDNIGHT. WILL ADD MENTION OF SOME FREEZING RAIN IN THE SOUTHWEST AFTER MIDNIGHT. TEMPERATURES ALOFT WILL BE TOO WARM FOR SNOW. AFTER THIS FEATURE MOVES THROUGH WE REMAIN DRY MONDAY AND TUESDAY AS A SHORTWAVE RIDGE TRAVERSES THE AREA. A SLIGHT SOUTHWEST FLOW RETURNS BY TUESDAY NIGHT...WITH MAYBE A FEW SPRINKLES ASSOCIATED WITH ANOTHER STRONG UPPER JET...BUT THIS WOULD BE WAY TO EARLY TO INTRODUCE ANY POPS AT THIS TIME. TEMPERATURES WILL REMAIN MILD THROUGH THE PERIOD...WITH LITTLE CHANGES TO PREVIOUS TEMPERATURE FORECAST. HIGHS ARE EXPECTED TO BE MAINLY IN THE 50S WITH LOWS OF 25 TO 35. .LONG TERM...WEDNESDAY THROUGH SATURDAY... THE MODELS DEVELOP AN UPPER LEVEL TROUGH OFF THE PACIFIC COAST BY WEDNESDAY MORNING...THEN MOVE THE TROUGH SLOWLY INTO THE PLAINS BY FRIDAY AFTERNOON...ALTHOUGH THE ECMWF KEEPS THE TROUGH TILTED WHICH SEEMS TO SPLIT THE MAIN DYNAMICS NORTH AND SOUTH OF THE FORECAST AREA. WITH THIS BROAD TREND WILL HOLD OFF MENTION OF PRECIP UNTIL FRIDAY...LIMITING THE POTENTIAL TO THE SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA...ENDING ON FRIDAY AS THE TROUGH MOVES THROUGH THE AREA. TEMPERATURES SHOULD RANGE FROM THE MID 40S TO LOWER 50S ON WEDNESDAY AND THURSDAY BUT SHOULD COOL TO 35 TO 45 FRIDAY AND SATURDAY. && .AVIATION...AS PER THE DISCUSSION ABOVE THERE WILL BE A SLIGHT CHANCE OF PRECIP TONIGHT...MAINLY IN THE SOUTHWEST AFTER 00Z AND SOUTHWEST AND SOUTH CENTRAL AFTER 06Z AFFECTING KDIK AND KBIS. AS TEMPS DROP ANY PRECIP AT KDIK COULD BE LIGHT FREEZING RAIN AFTER MIDNIGHT. POTENTIAL FOR PRECIP WILL SHIFT TO CENTRAL ND...KBIS TO KJMS...AFTER 12Z BUT DUE TO DAYTIME HEATING SHOULD REMAIN LIGHT RAIN. GUSTY WINDS THIS EVENING ACROSS THE NORTH SHOULD DROP OFF DURING THE EVENING...AND SHOULD REMAIN LIGHT THROUGH SUNDAY MORNING...INCREASING TO WEST 10 TO 20 MPH IN THE AFTERNOON. && .FIRE WEATHER... MINIMUM RELATIVE HUMIDITIES WILL CONTINUE TO BE IN THE MID TO UPPER 20S EACH DAY THROUGH TUESDAY. ON SUNDAY...WITH COLDER TEMPERATURES ALOFT...MINOT AND WILLISTON MIX OUT TO 800 AND 750 MB RESPECTIVELY ON GFS BUFR FORECAST SOUNDINGS. WILLISTON ESPECIALLY WOULD SEE SUSTAINED WINDS AROUND 20 WITH GUSTS TO 30 KTS. MINIMUM HUMIDITIES ACROSS THIS AREA ARE NOT FORECAST TO BE AS LOW AS THOSE OVER THE WEST CENTRAL AND SOUTHWEST. ALSO THE RANGELAND FIRE DANGER INDEX IS EXPECTED TO BE IN THE MEDIUM CATEGORY...POSSIBLY THE LOW END OF THE HIGH CATEGORY. WILL CONTINUE TO MONITOR...BUT FIRE WEATHER HIGHLIGHTS WILL NOT BE POSTED THIS AFTERNOON. ON MONDAY...WINDS ARE EXPECTED TO BE LIGHT. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...TWH AVIATION/LONG TERM...TSW