Heat, humidity and storm chances return this weekend

BALTIMORE -- After a couple of days of pleasant temperatures and lower humidity, that will come to an end as we head into the weekend. Expect a return to summer across the area with high humidity, high temperatures, and chances for showers and storms on Saturday and Sunday.

Overnight temperatures will only drop to around 70 degrees under partly to mostly cloudy skies as humidity surges back into the region. A warm front will lift through the area from Saturday morning into early Saturday afternoon. There may be a couple of showers with that front, but otherwise, the forecast will be dry.

Expect a mix of clouds and sunshine Saturday afternoon, with high temperatures reaching the upper 80s and lower 90s. The heat index will top 100 degrees in some parts of the area. Currently, the highest chances for strong to severe storms will remain to our west and north throughout the day Saturday. However, the atmosphere in the wake of the warm front will be very volatile. High heat, humidity, and wind shear mean any storm that pops up in the afternoon, either along the Bay Breeze or as a result of the prefrontal trough, could become severe quickly.

Any storms that develop Saturday afternoon and evening in the Baltimore area should be very isolated, with better coverage in Western Maryland and across the border in Pennsylvania. Better storm chances will begin creeping into the area after sunset as upper-level energy moves in from the west, increasing storm chances. Again, the best chances will be mainly west of Baltimore through Saturday night.

It appears that the Baltimore area and the rest of Maryland will have a better chance for showers and storms, some of which could be severe, on Sunday. The wind shear profile on Sunday will not be as favorable for tornadoes, but it looks to be more of a damaging wind threat for parts of Southern Maryland and the Eastern Shore.

Storms could fire up as early as late morning or early afternoon along the I-95 Corridor, then track south and east through the afternoon and evening into Southern Maryland and the lower Eastern Shore. This area will have the highest amount of instability, leading to a better chance for strong to severe storms.

We have issued WJZ First Alert weather days for both Saturday and Sunday in anticipation of the possibility of severe storms. Again, coverage on Saturday will be isolated throughout the afternoon and evening, with better coverage moving in later Saturday night into early Sunday morning. Expect slightly better coverage on Sunday afternoon east of the front, across southern portions of Maryland and the Eastern Shore.

High temperatures on Sunday will top out in the mid to upper 90s, and the heat index could exceed 100 degrees in many locations.

In the wake of the cold front at the start of next week, cooler and drier air will move in for Monday and Tuesday. Low temperatures will be back into the 50s and 60s by Monday night, with highs in the lower 80s Monday afternoon and lower to mid-80s on Tuesday.

We will return to a sultry summertime weather pattern on Wednesday, with higher humidity and highs near 90. For the 4th of July, temperatures will reach the mid to upper 90s with a chance for showers and storms. Expect the hot and humid weather to continue into Friday to close out the week.