Thunderstorm potential increases through the July 4th weekend with varying degrees of severe risks, primarily in the form of damaging wind threats.
The potent ridge of high pressure responsible for our ongoing heat wave this week will begin to weaken on Friday. This process will continue through the Independence Day weekend and into early next week.
This process will bring an end to the tropical temperatures and humidity we’ve been experiencing this week. It will also increase the threat of showers and thunderstorms through the weekend.
FRIDAY JULY 3
Scattered thunderstorms are forecast to develop Friday morning in Michigan and outflow boundaries from these storms may interact with the lake breeze off of Lake Erie in northern Ohio Friday afternoon. As such, areas in northern Ohio are favored for scattered thunderstorms during the afternoon and early evening.
Model guidance is highly variable, but some high-resolution models do suggest a scenario where storms form into a line southward toward the I-70 corridor this evening. The NWS Storm Prediction Center has extended the area of Slight Risk further south to cover this potential.
NOTE: Confidence is low in the potential for storms to line up and travel this far south. We’ll just have to “wait and see” if this scenario does indeed play out.
IF (and it is a big “if”) thunderstorms do come our way later this evening, strong wind gusts would be the primary concern, along with a much lower risk of hail.
SATURDAY JULY 4
The ridge continues to break down on Saturday. Support for thunderstorms appears to be higher than Friday’s. However, details on thunderstorm evolution, timing, and coverage are even more uncertain than Friday’s.
Model guidance as of Friday morning is all over the place. This is mainly due to the fact that much will depend on how things play out with Friday’s thunderstorms.
If you have outdoor plans on the Fourth, and many of us do, just be aware of the forecast trends over the next 24 to 36 hours. Scattered storms will be a possibility, but much is in question regarding the placement and timing of the storms. Timing as of Friday morning favors late afternoon into evening on Saturday.
SUNDAY AND MONDAY
Confidence is quite a bit higher early next week. An approaching cold front will provide a more definitive trigger for widespread thunderstorm development during the Sunday/Monday timeframe. The only limiting factor will be the amount of daytime heating that occurs beforehand.
Again, the timing favors peak heating during the late afternoon and evening. Strong wind gusts will remain the primary threat. In addition, some storms will have the added potential of producing tropical downpours.
THE BOTTOM LINE
Scattered thunderstorms will be around through the weekend and Monday. Some storms may bring strong wind gusts. The timing and placement are uncertain at this stage to model variances, but the afternoon and evening timeframes of each day are favored.
When Thunder Roars, Get Indoors.
