FNUS73 KLSX 201124 FWSLSX Spot Forecast for Logan Unit E...Missouri Department of Conservation National Weather Service Saint Louis MO 624 AM CDT Fri Mar 20 2026 Forecast is based on ignition time of 1000 CDT on March 20. If conditions become unrepresentative, contact the National Weather Service. .DISCUSSION... Well above normal temperatures will continue today with RH values hitting their minimum in the upper 20s this afternoon. Initially light southwesterly winds will become westerly and increase in speed to approximately 10-12 mph at 30 ft. The combination of RH and wind speeds will result in elevated fire conditions within the burn area. These factors will work with the westerly wind to promoting efficient upslow fire spread. There is a 60-70% chance winds will gust intermittently into the upper teens to low 20s this afternoon. Mixing will reach above 1,000 ft between 11 AM - 12 PM today and continue to mix into the afternoon, reaching a maximum between 4,000-5,000 ft by 3-4 PM. Winds between 10-25 mph within the mixed layer this afternoon will promote excellent some dispersion. A weak, dry cold front will move into the area this evening between 6-8PM, and winds will become light and northerly behind it. Cooling temperatures with sunset will cause RH to increase and the mixed layer to collapse, trapping any lingering smoke at the surface. **Please call the office to request a smoke dispersion model that starts from the burn and shows how the smoke plume will change over time under the forecast atmospheric conditions.** .REST OF TODAY... Sky/weather.........Sunny (15-25 percent). CWR.................0 percent. Chance of thunder...1 percent. Temperature.........64 at ignition...Max 83. RH..................63 percent at ignition...Min 31 percent. Eye level winds.....Light winds less than 1 mph using an adjustment factor of 0.1. Wind (20 ft)........Winds west at 7 mph at ignition...otherwise West winds 7 to 9 mph with gusts to around 19 mph shifting to the northwest around 7 mph late in the afternoon. Mixing height.......800 ft AGL at ignition...otherwise max 3900 ft AGL. Transport winds.....West 16 to 23 mph. Smoke dispersal.....Poor /1730 m/s-m/ at ignition. Max...good /11630 m/s-m/. TIME (CDT) 10 AM NOON 2 PM 4 PM 6 PM 8 PM Sky (%).........13 19 27 31 30 35 Weather cov..... Weather type....NONE NONE NONE NONE NONE NONE Tstm cov........ CWR.............0 0 0 0 0 0 Chc of thdr (%).0 0 0 0 0 0 Temp............64 75 82 83 79 69 RH..............63 45 32 31 36 51 20 ft wind......W 7 W 8 W 9 W 9 NW 6 N 3 20 ft wind gust.16 18 19 17 13 10 Eye level wind..W 3 W 4 W 4 W 4 NW 3 N 1 Eye lvl wnd gst.7 8 9 8 6 5 Mix hgt (kft)...0.8 1.9 3.1 3.9 0.7 0.4 Transport wind..W 16 W 18 W 22 W 22 N 12 N 10 Vrate kt-ft/1K..11 30 59 74 7 4 Ventrate Cat....POOR POOR FAIR GOOD POOR POOR .TONIGHT... Sky/weather.........Partly cloudy (30-40 percent) then becoming mostly clear (5-15 percent). CWR.................1 percent. Chance of thunder...3 percent. Temperature.........Min 48. RH..................Max 96 percent. Eye level winds.....Light winds. Wind (20 ft)........Northwest winds around 6 mph early in the evening becoming light. Mixing height.......Min 300 ft AGL. Transport winds.....North 9 to 12 mph shifting to the southeast 9 to 10 mph after 3 am. Smoke dispersal.....Poor (420 m/s-m). .SATURDAY... Sky/weather.........Sunny (10-20 percent). CWR.................1 percent. Chance of thunder...3 percent. Temperature.........Max 80. RH..................Min 38 percent. Eye level winds.....Light winds. Wind (20 ft)........Light winds becoming southwest 5 to 6 mph in the afternoon. Mixing height.......Max 3600 ft AGL. Transport winds.....South 7 to 9 mph shifting to the west 6 to 13 mph late in the morning. Smoke dispersal.....Poor (380 m/s-m) early in the morning increasing to fair max (6170 m/s-m) in the afternoon. $$ Forecaster...Delia Requested by...Nick LeMaster Type of request...PRESCRIBED .TAG 2606631.0/LSX .DELDT 03/20/26 .FormatterVersion 2.0.0