Saturday 10 A.M. Updated Discussion: *Level 2 snow emergency for Hamilton County / Only drive if you absolutely must as roads are in very bad shape* The longest/heaviest band of snow has pushed through much of the Cincinnati area. The snowfall max appears to be setting up right through the main Cincinnati metro region and on to the east. Latest radar and hourly (high resolution) forecast model trends indicate one more round of snow. The snow could still be heavy at times. Temperatures have warmed to 33-34 degrees with only another degree or two in warming likely.
The next heaviest band of snow is expected through the early to mid-afternoon hours. Another 1-2 (isolated 3″) will add on to our 4-6 already on the ground. Thus, a new max area on the snow map has been added to include 5-8 inches with a few isolated spots possibly seeing a little more than that. Elsewhere, 4-7″ still looks likely. Sleet and freezing rain may mix in south of the Ohio River as the next wave builds in.
Snow comes to an end by 4-6 p.m. this evening with a little patchy drizzle or freezing drizzle briefly possible after that. Mainly calm weather is expected this evening with temperatures dropping from the lower 30s into the middle 20s by Sunday morning.
1 A.M. Updated Discussion: Forecast still looks on track for probably the higher end of the original range. With sleet and freezing rain already being reported in Lexington/Louisville, I am hesitant to raise totals. However, as precipitation continues to intensify through the night, mid-level temperatures are likely to cool off a degree or two. Thus, snow is the expected dominant precip-type in metro Cincinnati through at least late morning. A narrow band of locally greater than 7 inches of snow may occur between northern Kentucky and Butler/Warren/Clinton counties. Stay tuned for future updates! (original article below)
After starting out in the negative teens this morning, southerly winds will usher in somewhat warmer air through the day. Clouds are forecast to increase through the afternoon but the entire region will remain dry though at least 9-10pm.
Winter Storm Warning in effect tonight through Saturday evening.
A large storm system that has been forecast to hit the Ohio Valley all week has been trending colder in the forecast models. Because of that trend, significant snowfall is now looking likely tonight and Saturday morning across much of the region. It is important to point out: The exact amount of warm air that the system pulls in (near and above the ground) is still not 100% ironed out. Very tiny changes in the temperature could result in a very different final outcome. Check back tonight and tomorrow for any updates to be posted at the top of this article.
Timing: Snow starts after 10 p.m. from west to east this evening. Moderate to heavy snow is likely later in the night through at least 6-8 a.m. A mixture of snow, freezing rain, and rain is likely through the morning. Freezing rain and rain will mix in first to the south of Cincinnati and move north through the morning. Leftover precipitation will change to plain rain by noon for Cincinnati. Farther north, a brief mix with rain is possible up to I-70.
Accumulation: 4-7 inches of snow through the early morning with some ice possibly mixed in. Rain may cut down on the final total of snow. *A glaze of ice on untreated roads, sidewalks, and cars may also develop despite temperatures climbing slightly above freezing.*
Impact: Roads will likely be snowy and icy through most of Saturday morning. Poor conditions may linger through the day especially on less traveled roadways.
An extremely complex forecast sets up tonight and Saturday as a weak area of low pressure brings a large amount of moisture into the Ohio Valley. With the low being weaker than previously forecast, the “surge” of warm air associated with it will also be weaker. Heavy snow is likely through much of tonight and at least early tomorrow morning. As temperatures near the ground and aloft warm above freezing during the early morning, the precipitation is expected to turn into a mix and possibly even plain rain by noon. The exact amount of warm air (and thus time and amount of mixed precip) is still not entirely certain.
Travel will likely become quite hazardous tomorrow morning as heavy snow falls. Even with temperatures expected to rise a few degrees above freezing, the temperature of roads, sidewalks, and cars will be affected by the recent cold. This means that even if “plain rain” falls at 34 degrees, some patches of ice may form on surfaces near the ground.
The bulk of the precipitation will fall by mid-afternoon with some drizzle possible afterwards. Temperatures will fall back below freezing Saturday evening so watch for re-freezing on area roads. The good news with this weekend forecast is that Sunday looks quiet. Unfortunately the cold does return for Sunday and most next week.
What could go wrong with the forecast?
Because we are riding the line between snow/mix/rain, here is some transparency regarding what small changes may affect the final outcome.
IF the warm layer of air moves in slower than forecast (or not at all) then snow totals will be near or above the high end of the forecast range. The overall model consensus does not show this, but a few models do. So while that is not the going forecast right now, it isn’t out of the question either.
If the warm air moves in faster than forecast, then snow totals will reside on the very low end of the forecast range.
Trends will need to be monitored through the afternoon and nighttime. Should any updates to the forecast be needed, check back as they will be posted at the top of this article.
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