ROCKFORD (WREX) — The heat is no stranger to the forecast of late, as temperatures have hit the 90° threshold quite a number of times since the start of meteorological summer on June 1st. As another week quickly approaches, the hottest temperatures of the year are about to settle in.
Sunday is forecast to be the hottest day of the next seven as high temperatures approach the lower and middle 90s. Heat index values to end the first weekend of July are going to touch the middle 90s before cooling off overnight into Monday.
Humidity for the back half of the weekend is going to remain in check, with dew points in the 60s likely for most of the day. While this is going to result in noticeable humidity and heat indices in the middle 90s, it'll be better than what settles in by midweek.
Here comes the humidity:
The Stateline has been able to stave off severe humidity for the last several days, however it is soon set to return. As a new work week gets underway, dew points are forecast to climb into the 70s. Anything greater than 70° is considered "uncomfortable" and typically results in much higher heat indices.
Model guidance suggests that by midweek, dew points could climb as high as the upper 70s. If this were to verify, heat index values would approach the 100° threshold. Highs by midweek are going to be in the lower 90s. A forecast high of 90° with a 70° dew point nets a heat index value of 96°. Plugging in model guidance dew point numbers of 78° results in a heat index value of 105°.
The potential for dangerous heat is there for the midweek period and could result in the issuance of a heat advisory if the pattern holds.
Remaining mostly dry:
Often times when patterns of hot weather persist, we look for precipitation chances to offer a brief reprieve. As of early Sunday, the threat for consistent heat-busting rain does not look likely. Isolated showers and storms are possible through midweek, with most of that activity being diurnally-driven. This means that widely scattered activity is likely during the peak heating hours.
Better chances for shower and storm coverage exist Thursday into Friday along an approaching cold front. In the meantime, no shortage of heat is ahead for the second week of July.