FNUS73 KFSD 221249 FWSFSD SPOT FORECAST FOR TAHOHPI WUI RX...USFWS NATIONAL WEATHER SERVICE SIOUX FALLS SD 749 AM CDT WED APR 22 2009 IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER SERVICE. .DISCUSSION...THE MAIN FEATURE TODAY IS A SURFACE RIDGE OF HIGH PRESSURE WHICH IS MOVING EASTWARD. CURRENTLY...THE HIGH PRESSURE AREA IS JUST EAST OF I 29...AND WILL NUDGE SLOWLY EASTWARD TODAY. ON THE WEST SIDE OF THIS HIGH IN YOUR AREA...WIND DIRECTIONS WILL CERTAINLY BY SOUTH TO SOUTHEAST BY MIDDAY. HOWEVER UNFORTUNATELY THERE WILL BE SOME GUSTINESS UP TO 25 MPH BY EARLY AFTERNOON. THE ABERDEEN WEATHER SOUNDING THIS MORNING IS SHOWING ABOUT 20 KNOTS AT THE TOP OF THE MIXED LAYER...JUMPING RAPIDLY TO 40 KNOTS JUST ABOVE THE MIXED LAYER. SO 25 MPH WIND GUSTS ARE CERTAINLY NOT OUT OF THE QUESTION ONCE WE HEAT UP. MIN RH VALUES WILL NOT BE TOO BAD AT 30 PERCENT...IT IS JUST THE GUSTINESS THAT IS CONCERNING ME SOME. UNFORTUNATELY THURSDAY DOES NOT BODE WELL EITHER...IN FACT IT COULD BE WORSE AS YOUR AREA AND FIRE WX ZONE 255 WILL BE VERY CLOSE TO RED FLAG CRITERIA. WILL HAVE TO EVALUATE THIS CLOSELY THIS AFTERNOON AND SEE IF WE NEED TO ISSUE A FIRE WX WATCH FOR YOUR AREA FOR THURSDAY. THE SOUTHERLY WINDS WILL LIKELY BE LIGHT ENOUGH BY LATE AFTERNOON OR EARLY EVENING ON THURSDAY...ABOUT 12 TO 17 MPH...BUT THIS IS A BIG BURN AND THAT MAY NOT GIVE YOU ENOUGH TIME TO COMPLETE IT BEFORE DARK. THE OUTLOOK IS NOT GOOD FOR SOUTHWEST TO SOUTHEAST WINDS. IF YOU CANNOT GET THE BURN OFF TODAY...WE MAY HAVE TO WAIT A WEEK BEFORE WE SEE THIS DIRECTION OF FLOW AGAIN. .TODAY... MAX TEMPERATURE.....73-78. MIN HUMIDITY........30 PERCENT. TIME (CDT) 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM SKY.............MCR MCR MCR MCR MCR MCR MCR MCR MCR MCR WEATHER TYPE.... TEMP (F)........45 49 54 58 63 67 70 73 74 74 RH (%)..........75 63 55 47 42 36 33 30 29 30 20 FT WIND DIR..ESE ESE E ESE SE SSE SSE SSE S S 20 FT WIND SPD..6 7 8 10 14 16 17 18 17 17 20 FT WIND GUST. 10 15 15 23 25 25 25 25 DISPERSAL INDEX.PR PR PR FR FR GD GD GD EX GD CHC OF PCPN (%).0 0 0 0 0 0 0 0 0 0 MIX HGT (KFT)...0.4 0.6 0.8 1.6 2.4 3.2 3.4 3.7 3.9 2.7 TRANSP WIND DIR.E ESE ESE SE SSE SSE S S S S TRANSP WIND SPD.7 10 14 15 15 16 18 22 23 23 HAINES INDEX....4 4 4 4 4 4 4 4 4 4 .TONIGHT... MIN TEMPERATURE.....50-55. MAX HUMIDITY........74 PERCENT. TIME (CDT) 6 PM 8 PM 10 PM MIDNGT 2 AM 4 AM SKY.............PCLDY PCLDY PCLDY PCLDY MCLEAR MCLEAR WEATHER TYPE....NONE NONE NONE NONE NONE NONE TEMP (F)........74 70 64 61 58 56 RH (%)..........30 36 46 56 64 66 20 FT WIND......SSE 15 SSE 13 S 13 SSE 14 SSE 15 SSE 13 20 FT WIND GUST.20 15 15 20 20 15 DISPERSAL INDEX.FAIR POOR POOR POOR POOR POOR CHC OF PCPN (%).0 0 0 0 0 0 .THURSDAY... MAX TEMPERATURE.....83-88. MIN HUMIDITY........25 PERCENT. TIME (CDT) 6 AM 9 AM NOON 3 PM SKY.............MCLEAR MCLEAR MCLEAR MCLEAR WEATHER TYPE....NONE NONE NONE NONE TEMP (F)........54 63 76 83 RH (%)..........71 58 37 25 20 FT WIND......SSE 13G15 S 16G25 S 21G30 S 24G30 DISPERSAL INDEX.POOR POOR GOOD EXCEL CHC OF PCPN (%).0 0 0 0 MIX HGT (FT)....300 500 2200 6300 TRANSPORT WIND..SSE 15 S 18 S 26 S 31 HAINES INDEX....5 6 6 6 $$ FORECASTER...MJF REQUESTED BY...CHARLES FROHME TYPE OF REQUEST...PRESCRIBED .TAG 20090422.TAHOH.01/FSD