458 FXUS63 KFSD 102348 AFDFSD AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 648 PM CDT TUE OCT 9 2012 .DISCUSSION.../ISSUED AT 333 PM CDT/ SOUTHWEST WINDS CONTINUE TO INCREASE ACROSS THE AREA AS GRADIENT TIGHTENS AHEAD OF A COLD FRONT APPROACHING FROM THE WEST. EXPOSED AREAS WILL LIKELY REMAIN BREEZY SO DESPITE DRY AIR...TEMPERATURES WILL BE SLOW TO FALL THROUGH THE EVENING. FRONT BARRELS THROUGH THE AREA THROUGH THE OVERNIGHT WITH STRONG LOW LEVEL COLD AIR ADVECTION BEHIND THE FRONT. THIS WILL RESULT IN GUSTY NORTH WINDS BEHIND THE FRONT. THE GUSTY WINDS WILL SLOWLY DECREASE THROUGH THE MORNING HOURS ON THURSDAY. MID LEVEL CLOUDS ARE EXPECTED TO LINGER ACROSS THE AREA MUCH OF THE DAY. WITH CLOUD COVER AND NORTH WINDS...IT WILL BE A STRUGGLE TO REACH 50 IN AREAS NORTH OF I-90. STILL EXPECTING ELEVATED FIRE DANGER WITH WINDS OF 15-25 KNOTS AND RELATIVE HUMIDITIES AROUND 30 PERCENT. SURFACE HIGH WILL SETTLE ACROSS THE CWA THURSDAY NIGHT...SO SHOULD SEE ANOTHER COOL NIGHT WITH LOWS GENERALLY IN THE 20S WITH CLEAR TO PARTLY CLOUDY SKIES. THE HIGH WILL SLIDE OFF TO THE EAST ON FRIDAY WITH SOUTHERLY WINDS INCREASING ACROSS THE CWA. TEMPERATURES WILL BE WARMER...BUT INCREASING HIGH CLOUDS AHEAD OF SYSTEM LIFTING OUT OF SOUTHWEST US WILL KEEP TEMPERATURES FROM WARMING TOO MUCH ESPECIALLY AS FLOW WILL BE MORE SOUTH SOUTHEAST AS OPPOSED TO SOUTHWEST...SO HIGHS IN THE 50S TO LOWER 60S WILL BE ABOUT AS WARM AS IT GETS. STILL LOOKS WET FRIDAY NIGHT INTO SATURDAY AS STRONG WAVE LIFTS NORTHEAST INTO THE PLAINS. MODELS ARE A BIT SLOWER AND BULK OF RAIN MAY HOLD OFF UNTIL AFTER 06Z SATURDAY...ESPECIALLY NORTHERN CWA. WILL SEE A RAPID INCREASE IN COVERAGE AFTER 06Z AS SYSTEM LIFTS NORTHEAST INTO NEBRASKA. SO HIGH POPS WILL BE CONTINUED AFTER 06Z ACROSS THE ENTIRE CWA. SATURDAY MAY BE A BIT TRICKY AS MODELS NOT ALL IN AGREEMENT WITH PLACEMENT OF UPPER LOW AND SURFACE LOW. GFS AND GEM LIFT THESE FEATURES INTO SOUTHEAST SOUTH DAKOTA SATURDAY AFTERNOON...WHILE ECMWF FURTHER SOUTHEAST IN WEST CENTRAL IOWA. NAM IS EVEN FURTHER NORTHWEST THAN GFS/GEM WHICH IS A TYPICAL NORTHWEST BIAS. THE ISSUE ON SATURDAY IS WHERE DRY SLOT WILL BE LOCATED AS RAIN COULD BE SHUNTED OFF FURTHER TO THE EAST DURING THE DAY. WITH UNCERTAINTY IN LOCATION WILL KEEP A CHANCE OF STORMS ALONG AND WEST OF I29 WITH HIGHER POPS TO THE EAST THROUGH THE DAY WHICH IS CLOSER TO ECMWF SOLUTION AS FINAL RESULT WILL LIKELY BE A BLEND BETWEEN THE ECMWF AND GFS. RAINFALL AMOUNTS WILL BE DECENT WITH A FAIRLY WIDESPREAD 0.50 TO 1 INCH THROUGH SATURDAY NIGHT. SYSTEM WILL PULL RAPIDLY AWAY SATURDAY NIGHT...WITH DRY AND MILD WEATHER ON SUNDAY. WILL REMAIN DRY AND MILD MONDAY AND TUESDAY WITH WEST TO NORTHWEST FLOW ALOFT BRING MILDER AIR INTO CWA. TEMPERATURES WILL BE ABOVE NORMAL BOTH MONDAY AND TUESDAY WITH ELEVATED FIRE DANGER. THIS COULD BE TEMPERED BY THE SOAKING RAINS FRIDAY NIGHT AND SATURDAY. WEAK COLD FRONT WILL PUSH THROUGH CWA TUESDAY NIGHT WITH COOLER TEMPERATURES ON WEDNESDAY. && .AVIATION.../FOR THE 00Z TAF ISSUANCE/ VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. SOUTH TO SOUTHWEST WINDS AHEAD OF APPROACHING COLD FRONT TONIGHT...WITH SOUTHWESTERLY LOW LEVEL JET OF 40-50KT EXPECTED AHEAD OF THE COLD FRONT BY LATE EVENING. WILL HAVE PERIOD OF LOW LEVEL WIND SHEAR AT KFSD/KSUX AS 40+KT WINDS DEVELOP AS LOW AS 1000-1500FT AGL. WINDS WILL BECOME GUSTY FROM THE NORTH WITHIN A COUPLE OF HOURS OF FRONTAL PASSAGE... ANTICIPATED IN NORTHWEST FORECAST AREA TOWARD KHON AROUND 06Z... 09Z-10Z FOR KFSD...AND EXITING SOUTHEAST FORECAST AREA INCLUDING KSUX 12Z-14Z RANGE. GUSTS WILL GENERALLY BE IN 15-25KT RANGE LATE TONIGHT THROUGH EARLY THURSDAY AFTERNOON...WITH WINDS DIMINISHING LATER THURSDAY AS SURFACE RIDGE AXIS MOVES INTO CENTRAL SD. && .FSD WATCHES/WARNINGS/ADVISORIES... IA...NONE. MN...NONE. NE...NONE. SD...NONE. && $$