Heat advisory issued for Southwestern Pennsylvania counties

The National Weather Service has issued an advisory for excessive heat in Southwestern Pennsylvania on Wednesday.

Counties covered by the advisory include all of Armstrong, Allegheny, Beaver, Butler, Greene and Washington counties, most of Westmoreland County with the exception of the eastern ridges, and the western half of Fayette County.

The advisory is scheduled to begin at 11 a.m. Wednesday and to be in effect until 9 p.m.

Temperatures in the mid-90s will combine with high humidity to create dangerously hot conditions this afternoon. Heat indices in the area will range from 99 to 103 degrees, according to the weather service.

Extreme heat and humidity will significantly increase the potential for heat-related illness, particularly for those outdoors.

Residents are advised to drink plenty of fluids, stay in an air-conditioned room and out of the sun, and to check on relatives and neighbors. Young children and pets should never be left unattended in vehicles.

There also is a threat of a few isolated, severe storms in the afternoon and early evening Wednesday, according to the weather service. Storms may be prevented from developing because of warm air aloft. But if a storm breaks through, it could produce damaging winds and/or large hail.

The weather service said there will be a better chance for strong-to-severe storms Thursday afternoon and evening in advance of a cold front. Conditions will be favorable for strong, damaging winds, with the possibility of large hail and a few tornadoes.

The weekend is expected to be cooler, with highs in the low to mid-70s, although highs in the low 90s are again expected on Tuesday and Wednesday.

Cooling centers open

In Pittsburgh, CitiParks will open four cooling centers until 7 p.m. Wednesday and Thursday.

Their locations:

• Greenfield Healthy Active Living Community Center, 745 Greenfield Ave.

• Homewood Healthy Active Living Community Center, 7321 Frankstown Road

• Sheraden Health Active Living Community Center, 720 Sherwood Ave.

• South Side Market House Healthy Active Living Community Center, 12th and Bingham streets

The city and CitiParks typically open cooling centers when the high temperature is forecasted to be above 90 degrees.

In addition, recreation centers also will be open.