Computer models continue to suggest a large winter storm will soon develop in the Ohio Valley. Outside of very light drizzle or mist tonight, no precipitation is expected until Tuesday evening at the earliest. Near and after midnight Wednesday, rain and snow will overspread the Tri-State. Most northwest of Cincinnati will see all snow (or little rain) very early Wednesday morning, but the rest of the Tri-State will see a mix of snow and rain. Through Wednesday morning and afternoon, cold air will wrap in behind low pressure, and accumulating snow will overspread southwestern Ohio, northern Kentucky, and the rest of southeastern Indiana.

Based on recent model trends, the threat for seeing a winter storm in the Tri-State has gone up slightly:

The SREF model (which is really a blend of models) suggest 1″+ is likely for much of the Tri-State between 4am and 4pm Wednesday. It also suggests significant chances for 4″+ and even 8″+ of snow in central Indiana, including the northwestern part of the Tri-State:

Just after 4pm this afternoon, the National Weather Service in Wilmington issued a Winter Storm WATCH for Fayette, Union, Franklin, Butler, and Warren County:

This watch is in effect from 1am Wednesday to 1am Thursday. This watch may be expanded or Winter Storm Warnings and/or Winter Weather Advisories may be issued in the next 24 hours. Travel will be difficult at times Wednesday, especially during the afternoon and evening.

There is still great uncertainty on the exact timing, strength, and positioning of this system. The forecast will likely change as new model data comes in and once the storm forms.

There will likely be a WIDE spread in totals from Connersville to Maysville. Some models have a spread of over 12″ of snow between these two cities. This will be an abnormally difficult forecast, and it will be very difficult to pin down snowfall amounts for any given location especially with blowing snow.

Thank you for your patience while we continue to make an accurate forecast. Stay tuned…

A winter storm is still forecast to affect the Ohio, Tennessee, and Mississippi Valley Tuesday through Thursday, but there are large discrepancies on the exact timing, positioning, and strength of this system. This is not unusual this far out. We are entering a time period where longer range models will wobble from one solution to the next and shorter range models are just now getting up to speed on where this area of low pressure will go.

In the shorter term, there is fairly high confidence that light rain and freezing rain will develop in the Tri-State tonight. The latest SREF model run shows rain for most at 1am tonight and the potential for freezing rain north of the Ohio River:

As temperatures go above freezing tomorrow morning and afternoon, the threat for freezing rain will diminish. Rain, however, will begin mixing with freezing rain and snow Monday evening and early Tuesday. Notice the latest SREF model showing a blend of freezing rain, rain, and snow by 7am Tuesday morning:

While there is no strong agreement in the latest round of model data on the potential for ice accumulation Monday night and early Tuesday, this signal from the SREF model is telling. While few will be going to work Christmas Day, the threat for ice accumulation Monday night and Tuesday morning needs to be watched carefully.

The strong model agreement regarding accumulating snow Tuesday night through Thursday is not as strong today. Both the early morning GFS and NAM model give the Cincinnati area little to no snow, but the ECMWF model remains consistent with it’s solution of heavy snow for much of Ohio, Kentucky, and Indiana. The latest outlook from NOAA’s Hydrometeorological Prediction Center shows the potential for 4″+ of snow from 7am Tuesday to 7am Wednesday west of Cincinnati:

Given the uncertainty in the latest model runs, no snowfall amounts will be released today, and totals and may not be released tomorrow. Releasing forecast snowfall totals too early just leads to empty promises; I would rather wait and issue a forecast with confidence than release it too early and mislead people.

Good afternoon! The flow off of Lake Michigan has been interrupted early this morning; this means early morning clouds are giving way to sun. While today will be quite sunny, high temperatures will only be in the low to mid 30s.

High pressure will relinquish control to low pressure Sunday. Clouds will overspread the Tri-State, and precipitation will begin developing in the afternoon. Precipitation will begin as rain Sunday afternoon and evening. The most recent SREF model run from this morning shows rain our area at 7pm Sunday night with the threat for freezing rain staying north of I-70:

With temperatures slowly falling through the 30s, freezing rain starts to become a possibility – especially north of Cincinnati – after midnight Monday. The latest SREF model run suggests rain is more likely south of the Ohio River at 7am Monday, while many north of Cincinnati will see ice mixing with rain:

Last night’s NAM model run is not impressed with the chance for ice accumulation north of Cincinnati early Monday morning, but last night’s GFS model run is. Note the potential for about a 0.1″ of ice in the northern Tri-State through 10am Monday morning:

Both rain and ice will be light Sunday afternoon through early Monday. An ice storm or heavy rain is not expected at this time. Even small amounts of ice, however, can lead to very slick roads and sidewalks.

This disturbance coming through early in the week will be weak, but it will help a second, larger disturbance form and move into the Ohio Valley Tuesday, Wednesday, and Thursday.

There are still some big positioning differences in the model data regarding this system. Note that this morning’s GFS model run has the center of low pressure over the Tri-State at 7am Wednesday morning, while last night’s ECMWF model run has the area of low pressure over Tennessee (Cincinnati is indicated as a white star):

Differences in the positioning of the system make a tremendous difference in what type of precipitation we will see, how heavy that precipitation we will be, and when we’ll see precipitation. A more southerly track tends to mean more snow for the Ohio Valley, but there’s more to it than that.

Last night’s GFS model run suggests more freezing rain Tuesday night and early Wednesday; a map of how much ice will accumulate according to the GFS from now through 7am Wednesday is attached:

While the exact placement of ice accumulation will likely change over the next few days,  it is worth noting accumulating ice will be a concern Tuesday night and Wednesday.

The most recent runs of the GFS and ECMWF models suggest accumulating snow is likely Wednesday and Thursday. Specific totals are unlikely to be released this weekend; we’ll have a better handle on amounts Monday and Tuesday.

Confidence is rising that a significant weather weather event – including snow, rain, and freezing rain – will unfold Tuesday, Wednesday, and Thursday in the Tri-State. Stay tuned!