000 FXUS63 KBIS 292003 AFDBIS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BISMARCK ND 305 PM CDT FRI AUG 29 2008 .SHORT TERM...FRIDAY NIGHT THROUGH MONDAY NIGHT UPPER LEVEL RIDGING TONIGHT AND SATURDAY WILL BRING DRY AND HOT WEATHER. THE NAM INDICATES H8 TEMPERATURES NEAR 30C IN THE WEST AND THIS WILL TRANSLATE INTO SURFACE TEMPERATURES IN THE 100 DEGREE RANGE. ALSO AS SATURDAY PROGRESSES THE RIDGE WILL MOVE FURTHER EAST AND THE FLOW ALOFT WILL BE BECOME SOUTHWESTERLY PROMOTING LEE SIDE SURFACE TROUGHING AND INCREASING SOUTHERLY SURFACE WINDS. NEXT...A DEEP UPPER TROUGH WILL BECOME THE FOCUS OF OUR WEATHER FOR THE REMAINDER OF THE SHORT TERM FORECAST PERIOD. THIS TROUGH WILL BE SLOW TO MOVE EAST PER ALL THE MODELS. AT THE SURFACE A COLD FRONT WILL LIE PARALLEL TO THE UPPER JET SO ITS PROGRESS TO THE EAST WILL BE VERY SLOW ALSO. SO WE WILL BE UNDER A THREAT OF THUNDERSTORMS FOR SEVERAL DAYS. ADDITIONALLY THE WARM TO HOT WEATHER WILL PERSIST EAST OF THE FRONT. THE FORECAST WILL SHOW AN INCREASING CHANCE OF THUNDERSTORMS...WITH THE GREATEST POPS ON MONDAY. I WILL BE USING THE SLOWER ECMWF FOR THE TIMING OF THE FRONTAL MOVEMENT. .LONG TERM...TUESDAY THROUGH FRIDAY NIGHT MODELS IN GOOD AGREEMENT IN THE LONG TERM. THIS PERIOD IS DOMINATED BY UPPER LEVEL TROUGHS WHICH WILL BRING A SHOWERY AND COOL TREND IN THE FORECAST. ON TUESDAY A WELL-DEVELOPED LONGWAVE TROUGH WITH A CLOSED LOW OVER THE FRONT RANGE IN MONTANA/WYOMING LIFTS NORTHEAST TOWARDS LAKE WINNIPEG. THIS WILL KEEP A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS IN THE FORECAST FOR THE AREA. WEDNESDAY THROUGH FRIDAY WILL BE DOMINATED BY A BROADER UPPER LEVEL TROUGH THAT SETS UP OVER CANADA AND THE CENTRAL US. HIGHS IN THE 60S AND 70S WITH LOWS IN THE 40S AND 50S DURING THE LONG TERM PERIOD. && .AVIATION... DRY SURFACE HIGH PRESSURE OVER THE STATE THIS AFTERNOON WILL MOVE EAST INTO MINNESOTA TONIGHT AS LOW PRESSURE DEVELOPS IN THE LEE OF THE ROCKIES FROM ALBERTA TO COLORADO. STRONG SOUTHERLY FLOW WILL DEVELOP BY 18Z ON SATURDAY WITH MAINLY CLEAR SKIES TONIGHT THROUGH SATURDAY AFTERNOON. && .FIRE WEATHER... I WILL KEEP THE WATCH FOR THE WESTERN HALF OF THE STATE IN EFFECT. RH'S WILL MEET CRITERIA AND SO WILL THE WINDS IN MOST OF THE WATCH AREA. WE MAY HAVE TO LEAVE THE NORTHWEST OUT OF A POTENTIAL WARNING AS WINDS MAY BE UNDER 15 MPH THERE TOMORROW. && .BIS WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING FOR NDZ001>003-009>011-017>021-031>034-040>045. && $$ RSL/JV