Friday will start out dry and mostly sunny, but low pressure will drag a strong cold front across east-central Ohio this afternoon. Showers and thunderstorms will develop along the front and sink southeast across the area late this afternoon and this evening.
Ahead of this evening’s thunderstorms, it will feel more like a mid-July day with temperatures warming to near 90 in most spots.
Here in the Valley, odds for showers and storms will ramp up as the front approaches. Instability and upper-level shear will be sufficient enough for severe thunderstorms in and around east-central Ohio. At this time, the main threat will come from damaging wind gusts. The Storm Prediction Center has portions of the east-central Ohio region highlighted for an Enhanced Risk for severe thunderstorms.
We don’t see enhanced risk here in our area very often. Enhanced is an elevated risk and should be taken with all seriousness. An Enhanced Risk means that numerous strong to severe thunderstorms will be possible in the highlighted area. Some could be intense.
CAPE, a measurement of how unstable the atmosphere is, will be fairly impressive during the afternoon and ahead of the cold front. Upper-level shear, or how fast the air is moving just overhead, will also be pretty brisk. Wind at that level will be clipping along at 50 – 60 mph. All that will be needed for storms to develop is moisture, and we have plenty of that with the elevated humidity as it is today, and a trigger – the cold front.
One factor that will work to our favor is timing. The front will approach and cross around sunset or just after sunset. Since we will be losing some daytime heating, instability will be decreasing.
WHAT WE CAN EXPECT
While a random shower or storm could certainly develop well ahead of the front but the main line of strong thunderstorms – the storms we are most concerned with – will occur along the boundary. This line of storms will travel southeast through east-central Ohio around a 6:00 PM to 10:00 PM timeframe.
Rain and storm odds will quickly diminish as the boundary sinks southward and drier air begins to work into the region tonight.
The main threat will be from damaging straight-line winds. However, there is also a slight chance for a few spinup tornadoes as well. The risk for a tornado in any one spot is low – but not zero.
The best odds for a severe thunderstorm here in the Valley is between 6:00 PM and 10:00 PM. This morning’s run of the high-resolution short-term model (HRRR) shows thunderstorms threatening the Valley at 7:00 PM:
The above animation should NOT be taken as verbatim, but it does have a pretty good idea of the timeframe thunderstorms should arrive and pass over the Valley. Notice that this will not be a long event. The line of storms will push through quickly bringing an end to the most active weather by 11:00 PM.
HIGH SCHOOL FOOTBALL
Unfortunately, this evening’s storms will be threatening at about the time area high school football games get underway. Thunderstorms, some strong to severe, will likely impact the area’s high school football games this evening.
Gusty wind and lightning will be the main threats for tonight’s games. Once the main line of storms moves through, lightning may persist for a period behind the main line. Expect game delays due to the lightning threat. For those attending, being in a stadium with metal supports is not a safe location to be when there is lightning around.
THE BOTTOM LINE
There is an elevated risk for severe thunderstorms this evening. Damaging wind gusts is the main threat, but a tornado or two cannot be ruled out. Some cells may produce brief heavy rainfall but the threat of widespread flooding is low.
Dry air will move in behind the front for Saturday as high pressure gradually builds in overhead. Saturday will be the cloudier day with a little upper-level moisture hanging around. Sunday will bring mostly sunny skies and dry conditions.
Temperatures through the period will be much cooler than what we’ve been seeing this week with afternoon highs around 70 degrees. Nighttime lows will be chilly Saturday night – low 50s. A little warmer Sunday night with lows in the mid-50s.
Our weather will turn a bit wetter next week. High pressure that brought us the cool but dry weekend, will shift east to New England by Monday. A warm front will lift north through Ohio increasing our chances for scattered showers. Then, a cold front will bring another round of precipitation Tuesday and Tuesday night. This may be another day where we will need to be aware of severe thunderstorms.
Cooler and drier air will return for midweek and a more autumn-like temperature regime should dominate through the rest of the month.