@ FNUS73 KFGF 201135 FWSFGF Spot Forecast for Hartleben WPA...USFWS National Weather Service Grand Forks ND 635 AM CDT Wed May 20 2026 Forecast is based on ignition time of 1200 CDT on May 20. If conditions become unrepresentative, contact the National Weather Service. Please call the NWS in Grand Forks at 701-795-5127 for additional information and monitor our website (www.weather.gov/fgf) or NOAA All-Hazards Radio for the latest updates. .DISCUSSION... Winds this morning will be generally light and variable but will increase from the south through the morning. As this occurs, wind speeds will also begin to increase to 10-15 mph sustained with occasional gusts by mid afternoon approaching 30 mph. With the recent rains, the expectation is for relative humidity to not crash as hard as it has over the past week, but will still have solid mixing to create low to mid 30s for minimum relative humidites by peak heating. Winds will remain southerly and elevated through the evening and overnight hours with relative humidity recovery generally to the 70s and 80s. .REST OF TODAY... Sky/weather.........Sunny (0-10 percent). Max temperature.....Around 65. Min humidity........33 percent. Wind (20 ft)........South winds 10 to 15 mph. Mixing height.......6400 ft AGL. Mixing winds........South 10 to 15 mph increasing to around 20 mph late in the afternoon. Smoke dispersal.....45200 knot-ft early in the morning increasing to 99200 knot-ft in the afternoon. TIME (CDT) 12P 1PM 2PM 3PM 4PM 5PM Sky (%).........1 1 1 5 5 8 Weather cov..... Weather type.... Tstm cov........ Temp............59 61 62 63 64 64 RH..............45 42 39 38 35 35 20 FT wind dir..S S S S S S 20 FT wind spd..10 10 10 15 15 15 20 FT wind gust.14 16 18 19 21 21 Mix hgt (kft)...4.5 5.4 5.8 6.4 6.2 6.2 Mixing wind dir.S S S S S S Mixing wind spd.10 15 15 15 15 20 Vrate kt-ft/1K..45 59 70 83 87 99 .TONIGHT... Sky/weather.........Partly cloudy (25-35 percent). Min temperature.....Around 40. Max humidity........86 percent. Wind (20 ft)........Southeast winds 10 to 15 mph. Mixing height.......400 ft AGL. Mixing winds........South 15 to 20 mph. Smoke dispersal.....93900 knot-ft early in the evening decreasing to 5900 knot-ft late in the night. TIME (CDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM Sky (%).........8 15 15 19 30 30 20 26 26 25 35 47 Weather cov..... Weather type.... Tstm cov........ Temp............65 63 61 55 52 50 48 47 45 43 42 42 RH..............33 38 44 53 56 58 65 68 70 79 82 82 20 FT wind dir..S S SE SE SE S S S S S SE SE 20 FT wind spd..15 15 15 10 10 10 10 10 10 10 10 10 20 FT wind gust.22 21 20 20 20 19 19 19 18 19 19 19 Mix hgt (kft)...5.9 5.1 0.8 0.5 0.5 0.5 0.5 0.5 0.4 0.4 0.4 0.4 Mixing wind dir.S S S S S S S S S S S S Mixing wind spd.20 20 15 15 15 15 15 15 15 15 15 15 Vrate kt-ft/1K..94 86 12 7 7 7 7 7 6 6 6 6 .THURSDAY... Sky/weather.........Mostly sunny (30-40 percent). Max temperature.....Around 68. Min humidity........34 percent. Wind (20 ft)........South winds 10 to 15 mph increasing to 15 to 20 mph in the afternoon. Mixing height.......6700 ft AGL. Mixing winds........South 15 to 20 mph. Smoke dispersal.....5800 knot-ft early in the morning increasing to 94600 knot-ft in the afternoon increasing to (115500 knot-ft) late in the afternoon. TIME (CDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM Sky (%).........42 49 37 25 23 23 28 35 26 30 41 42 Weather cov..... Weather type.... Tstm cov........ Temp............41 43 46 51 57 61 63 64 66 67 67 68 RH..............86 82 76 66 57 50 44 43 38 37 36 35 20 FT wind dir..S S S S S S S S S S SE S 20 FT wind spd..10 10 10 15 15 15 20 20 20 20 20 15 20 FT wind gust.18 19 19 20 22 23 23 23 23 23 23 23 Mix hgt (kft)...0.4 0.4 1.0 1.7 2.7 3.8 4.6 5.3 6.5 6.7 6.4 6.5 Mixing wind dir.S S S S S S S S S S S S Mixing wind spd.15 15 20 20 20 20 20 20 20 20 20 20 Vrate kt-ft/1K..6 6 16 29 48 72 87 95 117 121 116 117 $$ Forecaster...AP Requested by...Terry Gwilliams Type of request...PRESCRIBED .TAG 2614099.0/FGF .DELDT 05/20/26 .FormatterVersion 2.0.0 .EMAIL terry_gwilliams@fws.gov