Issued: 10am on Friday, July 28th 2023
Technical Forecast Discussion
Short-term (Friday 7/28/2023 through Sunday 7/30/2023):
The jet has settled into a more-zonal pattern at the moment, with a jet streak located above Ohio, with Western extent in the Upper Peninsula, into the Western part of Quebec. Cyclonic vorticity advection associated with Ohio’s relative position in jet streak and the 500mb vorticity maximum in Indiana will prove favorable for some diurnal-pattern thunderstorms as nighttime mixing begins and temperatures begin to drop for the evening. Since this is a relatively stable pattern, as the main point of development in this system will be the strengthening of a longwave ridge over the Central United States along with the vorticity minimum. This will cause a constant bombardment of these storms, which will “ride” the ridge into our region. The Storm Prediction Center current has parts of our forecast area in a Slight Risk for severe weather due to these ridge-riding storms, which will not harbor a large tornado-risk. But, discrete storms can be the cause of large hail, and a more organized system will bring severe wind. This current pattern also favors large area of warm-air advection, which can also instigate some upward motion. These storms will not bring any substantial chance of tornadic activity due to upper-level anticyclonic curvature in model-forecasted hodographs.
Warm-air advection will be a continued problem this weekend, as the ridge bring warm air into the region, therefore causing a warm air advection maximum in Western Ohio, which will kick off storm development in the evening through weekend as well. Warm air being funneled into the region this way will also be the cause of above-average temperatures for the reason today Friday and Saturday. This pattern will begin to turn into more of a longwave trough as we near Sunday.
Long-term (Monday 7/31/2023 through Thursday 8/3/2023):
Following Sunday, weather is expected to be milder, the zonal flow will turn into a strong longwave PNA-positive pattern. Where a very slow-moving longwave trough will situate over the Eastern United States. This pattern will see a rare summer cold-core high pressure system over Ohio, which will result in unseasonably cool temperatures for the beginning of the week. Expect high temperatures around the low to mid eighties, and nicer skies until the now-more meridional jet stream begins to finish its propagation towards Ohio. We’ll finally see an increase in temperature by Wednesday, as this ridge works its way to the Eastern United States, now degraded significantly from its most powerful, which has been causing the heat wave across the Central U.S. When this pattern shifts for the third time, we’ll see warmer temperatures, and a potential for some thunderstorms associated with what will likely be a warm front associated with the midlatitude cyclone that will then become cut-off North of Ohio, and potentially spoil the end of the week.
Friday-Sunday Morning: Warm temperatures with persistent evening thunderstorms following ridge into Ohio
Sunday-Wednesday: Cold-core high pressure system with clear skies, and seasonably cool temperatures
Wednesday-Friday: Transition to upper-level ridge with unsettled weather during transition, then warmer temperatures through Friday.