Lehigh Valley under heat advisory, excessive heat watch to start week

Lehigh Valley residents hoping for a reprieve from the most recent wave of blistering heat will have to wait a while longer as temperatures will flare up once again.

The National Weather Service has issued a heat advisory from 10 a.m. Sunday to 6 a.m. Monday, and an excessive heat watch from Monday morning through Tuesday evening in Lehigh and Northampton counties, as well as most of southeastern Pennsylvania.

Heat index values Sunday are expected to go as high as 101. On Monday and Tuesday, heat index values up to 108 are possible.

Residents are encouraged to drink plenty of fluids, stay in an air-conditioned room, stay out of the sun and check up on relatives or neighbors, especially those who are 65 and older. Anyone working outside should take frequent breaks, find shade when possible and wear loose-fitting clothing.

Saturday will merely be hot with temperatures reaching around 88 degrees, but temperatures will continue to rise with highs of 93 on Sunday, 95 on Monday and a scorching 98-degree high on Tuesday.

Besides the high heat, thunderstorms are also possible over the next several days. Scattered storms and showers were predicted Saturday morning before 11 a.m. Showers and storms are also possible Sunday before 2 p.m. and during the early afternoon and evening Monday. Here is the extended forecast from the National Weather Service.

Sunday: A slight chance of showers and thunderstorms after 2 p.m. Sunny, with a high near 93. Calm wind becoming west around 5 mph. The chance of precipitation is 20%.

Sunday Night: Mostly clear, with a low around 73. Calm winds expected.

Monday: A chance of showers and thunderstorms after 2 p.m. Sunny, with a high near 95. Calm wind becoming west around 5 mph in the afternoon. The chance of precipitation is 40%. New rainfall amounts of are expected to be less than a tenth of an inch, but higher amounts are possible in thunderstorms.

Monday Night: A chance of showers and thunderstorms, mainly before 8 p.m. Mostly clear, with a low around 72. The chance of precipitation is 30%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Tuesday: Sunny and hot, with a high near 98.

Tuesday Night: Partly cloudy, with a low around 76.

Wednesday: Showers likely and possibly a thunderstorm, mainly after 2 p.m. Mostly sunny, with a high near 95. The chance of precipitation is 70%.

Wednesday Night: Showers likely and possibly a thunderstorm before 8 p.m., then a chance of showers and thunderstorms after 8 p.m. Mostly cloudy, with a low of around 69. The chance of precipitation is 60%.

Thursday: A chance of showers. Mostly sunny, with a high near 85. The chance of precipitation is 30%.

Thursday Night: Partly cloudy, with a low around 64.

Friday: Mostly sunny, with a high near 85.