PHILADELPHIA (CBS) -- The Fourth of July holiday weekend kicks off hot and humid with scattered showers and storms. The Eyewitness News Weather Team is tracking the potential for severe threats later in the afternoon Saturday.
A Severe Thunderstorm Watch that was in effect for most of the region expired at 9 p.m. A Flash Flood Warning is in effect for Chester County in Pennsylvania until 9:15 p.m.
A very unstable air mass is overhead across the region with dew points in the 70s and temperatures nearing 90.
All that heat and humidity will set the stage for possible severe weather late Saturday and Sunday as a cold front sweeps through the region. The main threat from any storm will be intense lightning, gusty to damaging winds, and torrential downpours of more than an inch in 30 minutes.
The good news? Saturday will not be a washout.
Parts of the area may not even see showers and storms but with so many outdoor activities you need to locate a spot to dash indoors and wait out any storm that may develop nearby.
Widespread flooding is not expected, but a brief flash flood warning could be issued. There will also be intense lightning and pockets of hail.
The storm threat ends late Saturday night.
High pressure to the rescue Sunday.
Sunday will be pleasant. Any lingering clouds will clear to sunshine with much lower humidity with seasonable highs in the mid-80's.
Monday the Fourth of July looks sunny and hot with an increase in humidity. An isolated pop-up storm may be possible, but the chances are extremely low. Expect highs near 80 at the shore, mid-80's in the mountains, and closer to 90 in the city.
The skies look mostly clear for any firework displays in the evening.
If you are headed to the shore heed the flags or lifeguard warnings. There is a moderate risk of rip currents on Saturday.
Tuesday through Friday next week looks a bit unsettled with several disturbances bringing a chance of showers or storms at some point each day.
Stay with the Eyewitness News Weather Team for the most up-to-date forecast.
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