Bitter cold wind chills occurred across much of the area due to arctic air spreading across the region and remaining in place into the new year.
Every event with a place to put it; 51 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 DMX wrote it up.
Bitter cold wind chills occurred across much of the area due to arctic air spreading across the region and remaining in place into the new year.
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 Des Moines, IA wrote its last area forecast discussion before the first event at Dec 29, 3:24 PM CST, 9 hours 36 minutes earlier.
Area Forecast Discussion National Weather Service Des Moines IA 324 PM CST Fri Dec 29 2017 .SHORT TERM.../Tonight through Saturday/ Issued at 324 PM CST Fri Dec 29 2017 Snow continues across much of the northern and eastern portions of the forecast area with some fzdz across the far south. Accumulations so far across the north/east have been close to forecast amounts with areas in the main heavier band from near Algona to Fort Dodge to Marshalltown and Grinnell likely going to receive slightly higher amounts than previously forecast. The sites listed above will likely see amounts approach near 6 inches if not just above. Given the bulk of the heavier snow having already fallen, and impacts not much more with the area receiving 6 inches possibly versus 5 inches, and much of the snow tapering off during the evening commute will stick with the advisory and note upgrade to a warning. The back edge of the snow is across SE SD at this time and should see significant push of dry air into the state in the next few hours which should allow much of snow to taper off from northwest to southeast with the strong push of cold air moving in behind the cold front as well. In the far south, getting low level saturation and no ice introduction so have several reports of light freezing drizzle across the far southwest into south central Iowa. Have issued an advisory for that area through early evening. Any lingering precipitation past 00z should have enough cold air aloft to change over to light snow or flurries. Push of arctic air to come in tonight and will see winds pick up some and shift around to the northwest. Temps will drop and skies to see some clearing. Wind chills will fall as well with northern sites dropping into the -30 range, and the southern sites dropping to around -15 to -25 by Saturday morning. CAA to continue for much of the day with little recovery in temps or wind chills through the day Saturday. Will issue a wind chill warning for the north starting at midnight tonight and an advisory for the southern half starting in the early morning hours tonight. These will continue through the day Saturday. .LONG TERM.../Saturday night through Friday/ Issued at 324 PM CST Fri Dec 29 2017 Another weak wave to move through the region in northwest to westerly flow pattern aloft. This system may bring a dusting to up to an inch of snow to the southern half of the forecast area Saturday night. Arctic high pressure will then build across the region and into Iowa for Sunday into Monday with some of the coldest air Iowa has seen in some time moving into the state. Air temperatures will remain below zero for highs across much of the state Sunday and Monday, with overnight lows in the -10 to -20 range. Record lows are likely New Year's Day morning with the arctic blast continuing into Monday night. Winds will be in the 5 to 15 mph range during this time further exacerbating the cold bringing wind chill values down to -20 to -40 for much of the period Sunday into early Tuesday. Therefore have continued the advisory/warning combination that will be issued starting early Saturday through Tuesday morning at this time. Much of the advisory area will need to be upgraded into a warning for a period likely from late Sunday through early Tuesday. This can be done in later shifts. There will be a few brief time periods Saturday and Sunday that a portion of the forecast area may warm above advisory criteria but they will be short and not much warmer anyway, so will not mess around with those brief time periods and keep the headlines out for the entire time. As for the remainder of the period dry and cold conditions will persist. H85 temps remain cold for Tuesday through Friday, with some improvement from the frigid conditions as highs rise above zero and lows mainly in the single digits below zero. && .AVIATION.../For the 18Z TAFS through 18Z Saturday afternoon/ Issued at 1142 AM CST Fri Dec 29 2017 Low CIGS and VSBYS across the north today with the snow, which is expected to taper off from northwest to southeast by late afternoon/early evening. Low clouds to linger a bit longer with winds shifting around to the northwest behind a strong cold front late tonight. CIGS should go VFR at most locations toward sunrise with gusty northwest winds expected for the remainder of the period. && .DMX WATCHES/WARNINGS/ADVISORIES... Wind Chill Advisory from 4 AM Saturday to noon CST Tuesday for IAZ044>050-057>062-070>075-081>086-092>097. Winter Weather Advisory until 9 PM CST this evening for IAZ050- 062. Winter Weather Advisory until 6 PM CST this evening for IAZ004>007-015>017-023>028-033>039-046>049-061-070-071-081>084- 092>095. Wind Chill Warning from midnight tonight to noon CST Tuesday for IAZ004>007-015>017-023>028-033>039. && SHORT TERM...Beerends LONG TERM...Beerends AVIATION...Beerends
Hazardous Weather Outlook National Weather Service Des Moines IA 401 AM CST Fri Dec 29 2017 IAZ044-045-057>060-070>075-081>086-092>097-301015- Crawford-Carroll-Audubon-Guthrie-Dallas-Polk-Cass-Adair-Madison- Warren-Marion-Mahaska-Adams-Union-Clarke-Lucas-Monroe-Wapello- Taylor-Ringgold-Decatur-Wayne-Appanoose-Davis- 401 AM CST Fri Dec 29 2017 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...Today and tonight Light to moderate snow will fall across the outlook area today and into the evening across far eastern portions. One to three inches of new snow is expected but locally higher amounts may occur. .DAYS TWO THROUGH SEVEN...Saturday through Thursday An extended period of dangerously cold temperatures and wind chills are forecast Friday night through early next week. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed but snowfall reports would be appreciated. IAZ004>007-015>017-023>028-033>039-046>050-061-062-301015- Emmet-Kossuth-Winnebago-Worth-Palo Alto-Hancock-Cerro Gordo- Pocahontas-Humboldt-Wright-Franklin-Butler-Bremer-Sac-Calhoun- Webster-Hamilton-Hardin-Grundy-Black Hawk-Greene-Boone-Story- Marshall-Tama-Jasper-Poweshiek- 401 AM CST Fri Dec 29 2017 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...Today and tonight A winter weather advisory is in effect for the outlook area for 2 to locally 5 inches of snow. The snow will continue into the evening across far eastern portions of the area. Please refer to the National Weather Service website at www.weather.gov/desmoines for further details. .DAYS TWO THROUGH SEVEN...Saturday through Thursday An extended period of dangerously cold temperatures and wind chills are forecast Friday night through early next week. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed but snowfall reports would be appreciated. FAB
The national radar mosaic for the moment the first event began.
50 extreme cold/wind chill, 1 cold/wind chill. Local standard time, as filed.
Sustained, long duration dangerous wind chills of -25 to -40 deg F.
Sustained, long duration dangerous wind chills of -25 to -40 deg F.
Sustained, long duration dangerous wind chills of -25 to -40 deg F.
Sustained, long duration dangerous wind chills of -25 to -40 deg F.
Sustained, long duration dangerous wind chills of -25 to -40 deg F.
Sustained, long duration dangerous wind chills of -25 to -40 deg F.
Sustained, long duration dangerous wind chills of -25 to -40 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
Sustained, long duration dangerous wind chills of -25 to -35 deg F.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2017Every state in 2017This day in weather historyWarnings in Iowa, December 2017
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 2026-09-30. Each event’s entry at NCEI: 729991, 729992, 729993, 729994, 729995, 729996, 729997, 729998, 729999, 730000, 730001, 730002, 730003, 730004, 730005, 730006, 730007, 730008, 730009, 730010, 730011, 730012, 730013, 730014, 730015, 730016, 730017, 730018, 730019, 730020, 730021, 730022, 730023, 730024, 730025, 730026, 730027, 730028, 730029, 730030, and more.