Peoria, Ill. (WMBD) — The temperatures this week have been a wonderful change of pace from the five consecutive 90° days we had last week, though the lack of rain has been frustrating. Unfortunately a pattern change next week will bring another round of sweltering heat and mostly dry conditions to Central Illinois next week.
Temperatures will remain near to below average through the end of the week with little to no opportunity for storms. We’ll have one opportunity for showers and thunderstorms on Monday, August 1st, as we begin to transition to the hotter weather pattern. Some of these storms may be strong to severe but exactly where they will form remains uncertain. If we don’t receive rain then it could be a while before the next opportunity comes.
A strong ridge of high pressure will develop over the Midwest next week creating a heat dome that will send temperatures well into the 90s, and for some, the triple digits.
What is a heat dome?
When strong ridges of high pressure form and remain over a certain area for a prolonged period of time, it can create what we call a heat dome. Areas of high pressure bring sinking air which compresses, warms and dries as it moves towards the surface. This causes surface temperatures to warm which then leads to parcels of rising air which rise via a process called convection (i.e. boiling pot of water, thunderstorm development). While convection typically means rain, the high pressure system creates a capping inversion which in turns forces the air back down to the ground. The end result is a constant feedback loop of rising and sinking air that only gets hotter with each passing day.
There are some hints that a cold front will try to break this ridge down Thursday into Friday which would result in a chance of rain/storms and cooler temperatures, but confidence on this happening remains low. Even if it were to happen, the ridge will likely just redevelop and become even stronger over the weekend.
For now the forecast calls for temperatures to reach the low to mid 90s on Monday and Tuesday with mid to upper 90s expected Wednesday and Thursday. Depending on the strength and position of the high pressure center, we could see these temperatures end up being warmer than expected.