Frozen ground provided little means for drought conditions to change, despite 100-150 percent of normal precipitation.
Every event with a place to put it; 11 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
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.
Frozen ground provided little means for drought conditions to change, despite 100-150 percent of normal precipitation.
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 Dec 31, 10:15 PM CST, 1 hour 45 minutes earlier.
AREA FORECAST DISCUSSION National Weather Service Sioux Falls SD 1015 PM CST Thu Dec 31 2020 .SHORT TERM...(This Evening through Friday) Issued at 245 PM CST Thu Dec 31 2020 Latest observations across the region show mostly sunny skies, south to southeasterly winds, and temperatures in the low to mid 20s. Heading into the evening, expect a ridge of high pressure to gradually move overhead, allowing light and variable winds to prevail overnight. As a result, models continue to hint the fog development will be possible early Friday morning as winds remain light under a strong inversion. However, there is still a bit of uncertainty as to how widespread the fog will be, so have opted to carry patchy to areas of fog for now. Will continue to monitor trends in the meantime and make any adjustments if necessary. Otherwise, expect dry weather and quiet conditions to prevail heading into 2021, with afternoon highs Friday forecast to climb into the upper 20s to low 30s. .LONG TERM...(Friday Night through Thursday) Issued at 245 PM CST Thu Dec 31 2020 Quiet weather looks to continue throughout much of the extended period, with Wednesday appearing to be the next system that could bring precipitation chances back to the forecast. However, the overall moisture content associated with this feature looks fairly limited at this time, so will continue to carry only slight PoPs for now. In regard to temperatures, expect afternoon highs to remain in the upper 20s to low 30s, while overnight lows fall into the teens to low 20s. Could even see temperatures moderate a bit more, as latest CPC's 6-10 and 8-14 day outlook both forecast above normal temperatures for our area. However, given the current snowpack in place, we'll likely not see the full potential of this warming, so will continue to carry NBM's blended guidance for now. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 1015 PM CST Thu Dec 31 2020 Starting to see slight reductions in visibility as of 04Z, and guidance continues to point to fog development through the rest of the overnight, persisting through much of the morning on New Year's Day. With some expansion of high clouds into the region from the south, confidence in visibility dropping to 1/2SM or less is still on the low side, but will certainly monitor trends over the next few hours. If this were to occur, 10Z-17Z still appears to be the window favored by several model solutions, though am hesitant to include this in the TAFs at this point, as HREF probabilities of visibility below 1SM are only near or less than 50 percent. Visibility should improve Friday afternoon, but with little wind through the day to scour out residual boundary layer moisture, quite possible we could see a 2nd round of fog redevelop quickly Friday evening. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && SHORT TERM...SSC LONG TERM...SSC AVIATION...JH
Hazardous Weather Outlook National Weather Service Sioux Falls SD 1003 PM CST Thu Dec 31 2020 IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097- 098-NEZ013-014-SDZ038>040-050-052>071-020415- 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- 1003 PM CST Thu Dec 31 2020 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. Areas of fog will be possible overnight, especially in areas east of the James River Valley, including the Interstate 29 corridor and into northwest Iowa. Visibility may drop to less than a mile at times, and with temperatures below freezing, untreated roads may become frosty and slick. The fog could persist through much of the morning on New Year's Day. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Areas of fog will be possible again Friday night into early Saturday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
The national radar mosaic for the moment the first event began.
11 drought. Local standard time, as filed.
Extreme (D3) drought conditions continued through January.
Extreme (D3) drought conditions continued through January.
Extreme (D3) drought conditions continued through January.
Extreme (D3) drought conditions showed slight improvement to Severe (D2) drought during late January.
Severe (D2) drought conditions continued through January.
Severe (D2) drought conditions continued through January.
Extreme (D3) drought conditions continued through January.
Extreme (D3) drought conditions continued through January.
Extreme (D3) drought conditions continued through January.
Extreme (D3) drought conditions continued through January.
Extreme (D3) drought conditions continued through January.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2021Every state in 2021This day in weather historyWarnings in Iowa, January 2021
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: 935078, 935079, 935080, 935081, 935083, 935084, 935085, 935086, 935087, 935089, 935090.