By Llarisa Abreu

PHILADELPHIA (CBS) — A severe thunderstorm watch has been issued for the entire Philadelphia region Monday afternoon. The watch is set to expire at midnight.

High heat and humidity, with heat index values soaring to 97 degrees on the first full day of summer. A heat advisory has been issued for the Philadelphia metro until 8 p.m. Monday.

Evening storms are also on the menu. After 6 p.m. scattered storms will begin to fire up across our region. Strong storms are expected to form, especially across our western neighborhoods.

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These nasty thunderstorms could generate damaging gusty winds, hail, frequent lightning and an isolated tornado.

Torrential rain is also likely due to the abundant moisture over the area. That said, localized flooding is possible especially in low-lying and poor drainage areas.

The storms look to cross into Philly and along Interstate 95 closer to 9 p.m. — the storms should weaken significantly by the time the convection crosses into the coastal plain.

A strong cold front drops in on Tuesday, leading to pockets of stead to heavy rain starting late morning.

The heaviest rain should move offshore by 2 p.m. leaving behind scattered showers and a few embedded thundershowers.

The rain will bring a big drop in temperatures Tuesday and relief from the high humidity.

Drier and much more stable air builds on Tuesday night, giving way to a beautiful Wednesday and Thursday — with highs in the upper 70s and low humidity.

By Friday, humidity starts to creep back in, although rain and storms should hold off until Saturday.

TROPICS

Claudette has re-strengthened and is once again a tropical storm, bringing rain and wind to eastern North Carolina. While no direct impacts from Claudette are expected across our area, the system may churn up an increased risk for rip currents at the coast over the next couple of days.

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A well-defined Tropical Wave located 900 miles ESE of the Windward Islands has about a 20% chance of tropical development in the next 5 days.