Near normal temperatures and precipitation led to a brief period of severe (D2) drought around mid to late month.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS FSD wrote it up.
Near normal temperatures and precipitation led to a brief period of severe (D2) drought around mid to late month.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Sioux Falls, SD wrote its last area forecast discussion before the first event at Apr 20, 11:22 PM CST, 38 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Sioux Falls SD 1222 AM CDT Tue Apr 21 2026 .KEY MESSAGES... - Very high/near critical fire danger returns Wednesday and perhaps Thursday. - Low to moderate chances for showers and thunderstorms return Wednesday night into Thursday night. Isolated strong to severe storms are possible east of a Spencer to Sioux City line Thursday night. Confidence in severe weather threat is low due to poor model agreement in cold front progression. - Above normal temperatures persist through Wednesday, when highs of 80 to 95 degrees are expected. A pattern shift means cooler weather returns for the weekend with highs dropping back into the 50s and 60s. && .UPDATE... Issued at 840 PM CDT Mon Apr 20 2026 Red Flag Warning has been allowed to expire this evening as winds have quickly tapered down. However, a slower improvement in relative humidity keeps some elevated fire danger in place through the late evening. Continue to heed any local burn restrictions. High clouds continue to linger across eastern SD, with additional high clouds across the far western portions of the state as well thanks to a mid/upper level wave. This continues to move southeast through the night, and still anticipate mostly clear skies. No significant changes to the forecast for the next 12-24 hours, with lows in the upper 30s to mid 40s and generally light winds tonight as weak surface trough moves through. Tuesday is still on tap to be sunny and warm with relatively light winds. && .DISCUSSION... Issued at 206 PM CDT Mon Apr 20 2026 LATE THIS AFTERNOON: Looking across the region, temperatures range from the low 60s to around 70 degrees as of 2 PM. Deeper mixing than models expected has yielded gusts peaking 25 to 35 mph, but warm air advection has brought rising humidity (currently 21 to 35 degrees) and slow-to-warm temperatures. Dew points remain near the NBM 25th percentile. Periods of near-critical to critical fire danger will persist through sunset. See the Fire Weather section below for more details. TONIGHT AND TUESDAY: Winds weaken tonight as a dry, weak sfc trough slides in northwest flow, reducing fire danger. Mostly clear skies will pave the way for another chilly night, but a steep near-sfc inversion will keep lows a bit warmer than previous nights. Expect temperatures to bottom out in the mid 30s to mid 40s. Meandering on the dry side of a quasi-stationary front near the I-80 corridor means continued very dry conditions for Tuesday. Efficient mixing quickly through the nocturnal inversion into light winds aloft will make for a sunny, warmer spring day with high confidence highs ranging from the mid 70s (southwest MN) to mid 80s (Hwy 20 corridor and south central SD). WEDNESDAY: Notably hotter, windier, and dry conditions develop Wednesday in response to a 90th percentile (of NAEFS climatology) upper ridge building through. Currently have forecast high temperatures ranging from the lower 80s (east of I-29) to the lower 90s (west of the SD James River Valley), but see potential for temperatures to tick up a few degrees based on recent blend biases. A south wind mixing into a strong low level jet lends high confidence to gusts peaking in the 30s. Model forecast profiles show potential for some lower 40s gusts in south central SD. Higher winds combined with hotter weather brings high confidence in fire weather headlines across at least a portion of the area Wednesday and low confidence in fire danger on Thursday. See Fire Weather section for details. WEDNESDAY NIGHT THROUGH THURSDAY: A progressive upper low treks east into the Upper High Plains Wednesday night, introducing a low to moderate (<60%) chance for isolated showers and storms in central SD. This activity may progress eastward leading to some scattered showers and/or storms for the day Thursday. While agreement in a mid level speed max in the area is sufficient to warrant isolated severe storm threat, moisture and instability may be weak enough to prevent organized convection. Portions of northwest Iowa are currently highlighted in a SPC Day 4 Severe Weather Outlook, but will need to continue to monitor model trends as models differ greatly in the residence time in the warm sector and the speed of the associated cold frontal passage (slower Euro vs faster GFS/NAM). FRIDAY AND BEYOND: Behind Thursday's front, temperatures will be much cooler for the weekend with highs again dropping to the 50s and 60s and nightly lows near to below the freezing mark. The mid week upper low closes off over the Canadian prairie favoring below normal temperatures at least into early next week. The resultant zonal flow aloft brings lower confidence in next week's forecast with a moderate (20-40%) chance of at least some light rain (or rain/snow mix) Sunday night into Monday with a passing wave. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 1215 AM CDT Tue Apr 21 2026 Seeing some stronger (gusts around 25-30 knots) along the US Hwy 20 corridor and south as we mix into the LLJ. Expect this to end by 21.08-09z. Once we stop mixing into the LLJ, LLWS quickly develops along and just north of the US Hwy 20 corridor. Some guidance does show a couple hours of LLWS toward KFSD and the I-90 corridor; however, low enough confidence in occurrence to omit mention. For the rest of the period, winds will be variable in direction and relatively light, with gusts around 15 knots. VFR conditions prevail with a few high clouds. && .FIRE WEATHER... Issued at 206 PM CDT Mon Apr 20 2026 As of 2 PM, wind gusts have slightly exceeded expectations this afternoon with occasional gusts of 25 to 35 mph, but dew points have risen slightly faster than expected. This balance has brought occasional critical fire conditions across the region, but most persistently confined to the Red Flag Warning area. Near critical to critical fire danger persists across the region through early this evening due to low humidity and gusty south winds. High clouds near and east of a Huron to Sioux Falls to Sioux City line have limited heating a bit. Additionally, west of I-29, southerly winds have peaked and begun to weaken. Fire danger lessens considerably with sunset as winds weaken drastically and nighttime cooling commences. On Tuesday, dry air lingers with abundant sunshine and humidity dipping below 25 percent across the region. Fortunately lighter winds gusting mostly just in the teens should inhibit critical conditions from developing. Greater concern for fire danger returns Wednesday. The Hot-Dry-Windy Index highlights Wednesday afternoon as the main period of wildfire concern for the week with unseasonable warmth and south winds gusting 35 to 45 mph. Will be closely monitoring this period for potential fire weather headlines. Confidence in fire danger decreases for Thursday with low rain chances and increased cloudiness, but gusty winds and post-frontal dry air may ignite very high fire danger once again. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && UPDATE...SG DISCUSSION...BP AVIATION...SG FIRE WEATHER...BP
Hazardous Weather Outlook National Weather Service Sioux Falls SD 810 PM CDT Mon Apr 20 2026 IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097- 098-NEZ013-014-SDZ038>040-050-052>071-220115- Lyon-Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee- Buena Vista-Woodbury-Ida-Lincoln-Murray-Cottonwood-Nobles-Jackson- Pipestone-Rock-Dixon-Dakota-Beadle-Kingsbury-Brookings-Gregory- Jerauld-Sanborn-Miner-Lake-Moody-Brule-Aurora-Davison-Hanson-McCook- Minnehaha-Charles Mix-Douglas-Hutchinson-Turner-Bon Homme-Yankton- Union- 810 PM CDT Mon Apr 20 2026 This Hazardous Weather Outlook is for northwest Iowa, west central Iowa, southwest Minnesota, northeast Nebraska, central South Dakota, east central South Dakota, south central South Dakota and southeast South Dakota. .DAY ONE...Tonight. Although winds are diminishing, slower improvements to humidity may lead to elevated fire danger through late this evening. Continue to heed any local burning restrictions. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. Continued dry and windy conditions will lead to elevated fire concerns on Wednesday. Avoid any planned burn activities, and use caution with all outdoor activities. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
The national radar mosaic for the moment the first event began.
1 drought. Local standard time, as filed.
A brief period of severe (D2) drought conditions developed mid-month and improved to moderate (D1) again by late month.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Minnesota in 2026Every state in 2026This day in weather historyWarnings in Minnesota, April 2026
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1332846.