A band of rain slowly transitioned over to snow in the wake of a cold frontal passage.
Every event with a place to put it; 4 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 ILN wrote it up.
A band of rain slowly transitioned over to snow in the wake of a cold frontal passage.
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 Wilmington, OH wrote its last area forecast discussion before the first event at Dec 23, 5:58 AM EST, 2 minutes earlier.
Area Forecast Discussion National Weather Service Wilmington OH 558 AM EST Sat Dec 23 2017 .SYNOPSIS... A cold front will slip southeast through the remainder of the region today while low pressure ripples along it across the eastern Ohio Valley. Widespread precipitation is expected this morning, which will then taper off quickly from west to east this afternoon. An upper level disturbance will move through Sunday into Sunday night, bringing snow to the Great Lakes and Ohio Valley. Christmas Day will be dry but cold as high pressure builds into the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A cold front was located across our eastern and southern CWFA this morning. Low pressure located over northwest Tennessee will ripple northeast along the front as the front itself pushes southeast through the remainder of our area this morning. Widespread precipitation across the region was being aided by a strong low level jet along with upper level dynamics by a pivoting s/wv. Model soundings still indicate that rain will change over to a period of wet snow this morning, mainly for the Whitewater/Miami Valley, west central Ohio, and parts of central Ohio (north of Columbus). Along the southern periphery of this region, rain may mix with snow, with rain expected elsewhere. Precipitation will quickly taper off from west to east this afternoon as the low pulls away. Will continue to forecast 1 to 2 inches of wet snow in the aforementioned areas with little accumulation expected elsewhere were the snow mixes with rain. Since we are starting out on the warm side, and with road surfaces temperatures hovering around freezing, most of the snow should be slushy or wet, especially as sub road temperatures remain above freezing. Nonetheless, will continue with an SPS for the 1 to 2 inches given that its the holiday weekend. Temperatures will slowly fall most locations this morning, then level out during the afternoon, with all locations in the 30s by then. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... Some post CAA stratus/stratocumulus will linger across the eastern/southern forecast area this evening. These clouds will be followed quickly by mid and high level clouds streaming out ahead of the next weather system to affect our area Sunday into Sunday night. As weak high pressure ridging temporarily builds in overnight, expect overnight lows to range from the lower 20s northwest to the upper 20s southeast. && .LONG TERM /SUNDAY THROUGH FRIDAY/... The two main themes for the forecast for Sunday and beyond are in increasing confidence in snowfall for the northern half of the ILN CWA on Sunday, and increasing confidence in cold conditions through the rest of the week. With regards to the snow on Sunday, the 00Z model suite appears to be in generally good agreement on the overall setup. A broad (but gradually sharpening) shortwave trough over the middle/northern Mississippi Valley region early Sunday will move ENE over the course of the day, spreading broad ascent and a saturating column into the northern Ohio Valley and southern Great Lakes by afternoon. Depictions of this shortwave are a little better defined than they were with the 00Z suite yesterday, with a strengthening 500mb jet streak (100 knots by Sunday afternoon) positioned along the southern extent of the trough -- undoubtedly aiding with some left exit region support. This system does still appear to be somewhat lacking in lower level support, but weak surface low pressure does seem likely to develop in eastern Kentucky and into West Virginia, moving northeast throughout the afternoon. Not sure if this will be strong enough to significantly aid in the forcing, and frontogenesis / deformation projections show only muted or inconsistent signals across the suite of models. Aside from this feature, surface high pressure will be gradually building into the region as the day progresses. There is relatively high confidence in the overall placement and timing of precipitation, with an initial WSW-to-ENE band moving into the northern ILN CWA by late morning, and more widespread precipitation following as the shortwave approaches in the afternoon and evening. PoPs have been increased slightly again, but more notably, snowfall totals in the northern couple tiers of ILN counties have also been increased again -- now allowing for an area of 2-3 inches. Depending on the orientation of the initial band (and if it can register any low-level support) there is some chance for this to even be exceeded, and hopefully this will come better into alignment soon, especially as the event gets within range of some of the other WRF runs. There was actually very little change to snowfall numbers for the rest of the CWA, with an inch or two near and just south of the I-70 corridor, and much less further south. Also of note is that the cooling air mass may result in greater-than- climo snow ratios (16:1 to 18:1 per this forecast) as a result of two factors -- an isothermal layer within the dendritic growth zone near the onset of snow, and steepening low level lapse rates later in the day. Conditions for snow favorability decrease markedly with southward extent across the CWA, as the air mass warms considerably with southward extent, and forcing also decreases significantly -- to the extent that only a few tenths are forecast late in the event in the southern tier or two of ILN counties. Temperatures may actually warm enough in the far SE to allow some rain to mix in during the afternoon, but with nearly negligible QPF amounts, that may not end up mattering much anyway. Highs are expected to range from the upper 20s to upper 30s. Through the rest of the week, or at least through Thursday, the main story will be the constant run of cold advection into the Ohio Valley. As confidence continues to increase in this scenario -- and confidence also increases in the prospects of having some snow on the ground (mainly in the northern half of the CWA) -- temperatures have been lowered slightly across several forecast periods. Yes, this is essentially the same message as has been noted in the past few forecast cycles -- the forecast does, indeed, continue to get colder. Aside from just having some decreases in the temperature forecasts, the gradient in temperatures is also expected to be somewhat pronounced -- again, the expectation of some snow cover in the northern ILN CWA has an obvious role in this. Current expectations are for Wednesday to be the coldest day of the period, with min temps Wednesday morning ranging from the middle single digits to the upper teens from N to S, and max temps of middle teens to upper 20s from N to S. Not coincidentally, both the GFS/ECMWF show the coldest 850mb temperatures over the region at 12Z Wednesday, though the ECMWF remains the colder of the two models. On another note, there still is a low-confidence chance of some snow on Tuesday, with models continuing to indicate a weak/transient shortwave moving through the area. Given a wide array of timing/placement issues with this, and no indications of any significant QPF or forcing, PoPs will be kept on the low end with no accumulations forecast. By Thursday night and into Friday, there are signs of more active weather conditions becoming possible, as another round of troughing develops over the middle of the CONUS. Simply not possible to look for specifics with this as of yet, so only low-end PoPs will be kept in the forecast. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... Frontal boundary located northeast to southwest through the southern part of the region this morning will make its way toward the south and southeast as low pressure rides along it through the Ohio Valley. Plenty of low level and upper level dynamics to result in widespread precipitation. Colder air will be drawn southward as the low strengthens some as it heads northeast through eastern Kentucky and West Virginia. This will allow rain to briefly change to snow at KDAY before ending and mixing with snow at KCMH/KLCK/KILN before ending. The southern terminals of KCVG/KLUK are expected to remain in rain for the duration. Ceilings and visbilities will be low this morning (IFR ceilings, MVFR/IFR visbilities) until precipitation moves away by the afternoon. Thereafter, post frontal CAA stratus/stratocumulus will remain with ceilings remaining around 1500 feet. For tonight, the region will be between systems. Some weak ridging is expected with low clouds breaking up, providing for a return to VFR conditions. We should see some mid and high level clouds moving in overnight in advance of the next weather system to affect the region Sunday into Sunday night. OUTLOOK...MVFR/IFR ceilings and visibilities likely Sunday into Sunday night. MVFR ceilings possible Monday night into Tuesday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && SYNOPSIS...Hickman NEAR TERM...Hickman SHORT TERM...Hickman LONG TERM...Hatzos AVIATION...Hickman
Hazardous Weather Outlook National Weather Service Wilmington OH 327 AM EST Sat Dec 23 2017 INZ058-059-066-073>075-080-KYZ089>100-OHZ046-053>056-060>065-070>074- 077>082-088-241200- Fayette IN-Union IN-Franklin IN-Ripley-Dearborn-Ohio-Switzerland- Carroll-Gallatin-Boone-Kenton-Campbell-Owen-Grant-Pendleton-Bracken- Robertson-Mason-Lewis-Delaware-Clark-Madison-Franklin OH-Licking- Preble-Montgomery-Greene-Fayette OH-Pickaway-Fairfield-Butler-Warren- Clinton-Ross-Hocking-Hamilton-Clermont-Brown-Highland-Adams-Pike- Scioto- 327 AM EST Sat Dec 23 2017 This Hazardous Weather Outlook is for East Central Indiana, Southeast Indiana, Northeast Kentucky, Northern Kentucky, Central Ohio, Southwest Ohio and West Central Ohio. .DAY ONE...Today and Tonight. The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Accumulating snow of an inch or less will be possible Sunday into Sunday night. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. INZ050-OHZ026-034-035-042>045-051-052-241200- Wayne-Hardin-Mercer-Auglaize-Darke-Shelby-Logan-Union OH-Miami- Champaign- 327 AM EST Sat Dec 23 2017 This Hazardous Weather Outlook is for East Central Indiana, Central Ohio and West Central Ohio. .DAY ONE...Today and Tonight. Snow accumulations of 1 to 2 inches are possible today. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Additional accumulating snow is expected Sunday into Sunday night. Snow accumulations of 1 to 3 inches will be possible. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report snow accumulations to the National Weather Service.
Special Weather Statement National Weather Service Wilmington OH 320 AM EST Sat Dec 23 2017 INZ050-OHZ026-034-035-042>045-051-052-231700- Wayne-Hardin-Mercer-Auglaize-Darke-Shelby-Logan-Union OH-Miami- Champaign- Including the cities of Richmond, Kenton, Ada, Celina, Coldwater, Wapakoneta, St. Marys, Greenville, Sidney, Bellefontaine, Marysville, Troy, Piqua, Tipp City, and Urbana 320 AM EST Sat Dec 23 2017 ...ACCUMULATING SNOW TODAY AND SUNDAY... Two weather systems will bring accumulating snow to the area this holiday weekend. The first system will have rain transitioning to snow this morning. Snow is then expected to taper off fairly quickly this afternoon. Snow accumulations of 1 to 2 inches will be possible. The second system will bring snow to the region Sunday morning through Sunday evening. An additional 1 to 3 inches of snow will be possible with this weather system. Motorists are advised to use extra caution if traveling this holiday weekend with the potential for accumulating snow. Slick spots will be possible on area roadways along with reduced visibilities.
The national radar mosaic for the moment the first event began.
4 winter weather. Local standard time, as filed.
The county garage measured an inch of snow south of Wapakoneta, as did the CoCoRaHS observer 3 miles south of St. Mary's.
The county garage measured two inches of snow west of Celina while law enforcement measured an inch in town, as did a spotter in Maria Stein.
An observation from Ada showed that an inch of snow accumulated there.
The observer just north of Fort Loramie measured an inch of snow.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Ohio in 2017Every state in 2017This day in weather historyWarnings in Ohio, 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 2026-09-24. Each event’s entry at NCEI: 729851, 729852, 729853, 729854.