Lehigh Valley Weather

Experts say there’s confusion about how quickly heat and moisture can compromise everyday medicines like insulin, inhalers, blood thinners and common antibiotics.

The National Weather Service has issued a flood watch for Lehigh and Northampton counties — along with much of eastern Pennsylvania and parts of New Jersey — from Monday afternoon through the evening.

A cold front colliding with a surge of tropical moisture is expected to produce widespread showers and storms, triggering a flood watch for the Lehigh Valley and much of eastern Pennsylvania.

Moisture from Tropical Depression Chantal will bring the chance for scattered showers and downpours to the region, kicking off a stretch of unsettled weather with daily chances for storms throughout the week.

After Monday brought rounds of thunderstorms and heavy rain, more severe weather is expected to target the region on Tuesday, forecasters say.

The heat this week was one of the hottest stretches of weather ever recorded in parts of the Mid-Atlantic and Northeast.

After days of sweltering heat, the Lehigh Valley can finally expect a break as a cold front brings modest relief and cooler temperatures, forecasters say.

On Tuesday afternoon, Lehigh Valley International Airport recorded temperatures that tied the record heat set in Allentown over a century ago on June 24.

No climate site in the region reached 100 degrees on Monday, but the suffocating heat and humidity was still record-setting across the Mid-Atlantic region.

PJM Interconnection, the regional grid operator headquartered in Valley Forge, issued a maximum generation alert and load management alert for Monday.