FNUS73 KFSD 281351 FWSFSD SPOT FORECAST FOR BIG SIOUX UNIT...IOWA DNR NATIONAL WEATHER SERVICE SIOUX FALLS SD 851 AM CDT TUE APR 28 2009 IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER SERVICE. .DISCUSSION...AS A SURFACE RIDGE OF HIGH PRESSURE MOVES EAST OF THIS AREA...THE SURFACE WINDS WILL BECOME SOUTHEAST. NORTHEAST WINDS WILL TRANSITION TO SOUTHEAST BY EARLY THIS AFTERNOON AND INCREASE TO 15 TO 20 MPH. AS TEMPERATURES WARM THIS AFTERNOON...RELATIVE HUMIDITIES WILL FALL TO NEAR 35 PERCENT IN THE MID AND LATE PORTIONS THIS AFTERNOON. TONIGHT THROUGH WEDNESDAY NIGHT WILL THEN BE MARKED BY UNSETTLED WEATHER. A SERIES OF UPPER AIR DISTURBANCES WILL MOVE THROUGH THIS AREA IN A WAVY PATTERN. THESE DISTURBANCES WILL GIVE GOOD CHANCES FOR WETTING RAINS IN THE FORM OF SHOWERS AND THUNDERSTORMS...WITH WEDNESDAY LIKELY BEING A DAMP DAY MOST LOCATIONS. THE SURFACE COLD FRONT WILL MOVE THROUGH THIS FORECAST AREA WEDNESDAY NIGHT...WITH LINGERING LIGHT PRECIPITATION CHANCES ONLY IN SOUTHWEST MINNESOTA...NORTHWEST IOWA AND EXTREME SOUTHEAST SOUTH DAKOTA ON THURSDAY. FRIDAY COULD SEE A FEW LIGHT SHOWERS ALONG AND SOUTH OF I 90...BUT THOSE CHANCES ARE PRETTY QUESTIONABLE. LIGHT SHOWERS OR NO...THURSDAY AND FRIDAY WILL BE SEASONABLY COOL. .TODAY... MAX TEMPERATURE.....58-63. MIN HUMIDITY........35 PERCENT. TIME (CDT) 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM SKY.............CLR MCR MCR MCR PC PC PC MCR MCR WEATHER TYPE.... TEMP (F)........43 46 49 52 55 57 59 61 61 RH (%)..........65 60 54 48 43 40 37 35 35 DEWPOINT (F)....32 33 33 33 33 33 33 33 33 20 FT WIND DIR..E E E E E E ESE ESE ESE 20 FT WIND SPD..10 12 13 13 13 13 14 14 14 20 FT WIND GUST. 15 15 15 15 15 20 20 20 DISPERSAL INDEX.PR FR GD GD GD GD GD GD EX CHC OF PCPN (%).0 0 0 0 0 0 0 0 0 MIX HGT (KFT)...0.9 1.6 2.2 2.9 3.5 3.5 3.6 3.6 3.9 TRANSP WIND DIR.E ESE ESE ESE ESE ESE ESE ESE ESE TRANSP WIND SPD.16 20 18 17 15 16 18 20 21 HAINES INDEX....3 3 3 2 2 2 2 2 2 .TONIGHT... MIN TEMPERATURE.....41-46. MAX HUMIDITY........79 PERCENT. TIME (CDT) 6 PM 8 PM 10 PM MIDNGT 2 AM 4 AM SKY.............MCLEAR PCLDY PCLDY MCLDY MCLDY MCLDY WEATHER COV..... CHANCE CHANCE WEATHER TYPE....NONE NONE NONE NONE TSTORM TSTORM TEMP (F)........60 57 52 50 47 46 RH (%)..........36 42 52 61 71 76 DEWPOINT (F)....33 34 35 37 38 39 20 FT WIND......ESE 13 ESE 12 ESE 10 SE 10 SE 12 SE 12 20 FT WIND GUST.15 15 15 15 15 15 DISPERSAL INDEX.EXCEL GOOD POOR POOR POOR POOR CHC OF PCPN (%).0 10 10 10 40 40 MIX HGT (FT)....4200 3000 300 300 300 300 TRANSPORT WIND..ESE 21 ESE 18 ESE 12 SE 12 SE 13 SE 13 HAINES INDEX....2 2 2 3 4 4 .WEDNESDAY... MAX TEMPERATURE.....54-59. MIN HUMIDITY........69 PERCENT. TIME (CDT) 6 AM 9 AM NOON 3 PM SKY.............MCLDY CLOUDY CLOUDY CLOUDY WEATHER COV.....CHANCE SCTTRD SCTTRD LIKELY WEATHER TYPE....TSTORM TSTORM TSTORM TSTORM TEMP (F)........45 48 53 56 RH (%)..........79 74 69 69 DEWPOINT (F)....39 40 43 46 20 FT WIND......ESE 10G15 ESE 15G20 ESE 18G25 ESE 18G30 DISPERSAL INDEX.POOR FAIR GOOD GOOD $$ FORECASTER...BT REQUESTED BY...CHRIS LARUE TYPE OF REQUEST...PRESCRIBED .TAG 20090428.BIGSI.01/FSD