A cold front will move through the region later today bringing a chance of showers and thunderstorms to Ohio.
As this front moves in there is the chance it could spark some severe weather here in Ohio. Here is a look at the current severe weather outlook from the Storm Prediction Center for Monday.
Notice that all of Ohio is under a “Slight Risk” area. This means that the overall threat for severe weather is low with the biggest concern this afternoon and evening being some isolated damaging wind and hail. There is the chance for an isolated tornado or two in the Great Lakes region. Here is a look at the probability of a tornado within 25 miles of any point on the map from the SPC. Based on the map below the overall chance is low, but 5 percent over Ohio is worth noting.
One thing that could in fact dull our chance for severe weather this afternoon here in West Central could be our current cloud cover hanging around much of the morning and early afternoon. A look at the high-resolution visible satellite across the region shows very few breaks in the clouds through NW Ohio and Indiana.
If we manage to stay under mostly cloudy skies our chance for severe weather will lessen simply due to the fact that our daytime heating potential won’t be reached. Basically, if we see some good sunshine late this morning/early afternoon our chance for severe storms goes up. If we see mainly cloudy skies and no sunshine, it goes down.
You can see here based on the HRRR which is a high-resolution weather forecast model used for severe weather that the CAPE values (Convective Available Potential Energy) are fairly low. They will generally be between 500 and 1,000 j/kg. Here is a look at CAPE around 4 PM this afternoon.
These are not high CAPE values by any means. But there is also one other ingredient that may be strong enough to overcome this low instability to help form stronger storms.
As this cold front moves through wind shear values look pretty high. Wind shear is any change in wind speed OR direction with height in the atmosphere. This change helps to maintain and grow thunderstorms. A quick look at wind shear values along the front as it passes through this afternoon look to be more than enough to fire up thunderstorms in conjunction with the lower CAPE values I noted above. Here is a look at shear around 4 PM this afternoon.
In the above map we’re generally looking at 30 to 40 knots of shear in the 0 to 6 kilometer level of our atmosphere. 30 to 40 knots is pretty high, anything above 50 or so is getting VERY high and more than enough to spark a pretty wide outbreak of severe weather.
So what do I think?
Forcing mechanism (cold front), check. Wind shear this afternoon, check. Instability (CAPE) half check.
I generally look for these three ingredients to all come together at the same time for severe weather. They do a decent job of this at best this afternoon but I have seen much better collaboration in the past. Because of this, our overall threat is low but damaging wind, hail or even an isolated tornado can’t be ruled out this afternoon/evening between 2 PM and about 8 PM.
I’ll be sure to keep you all updated through the afternoon! And remember, you can download our weather app to keep up on the latest radar along with watches/warnings that may be issued.