Warm and Humid for the Fourth

Tuesday 10 a.m.

Extremely moist air remains in place from Florida to Maine, and there are areas of showers and thunderstorms scattered through this zone. The activity typically peaks in the afternoon hours and wanes at night. Be ready for locally flooding downpours, realizing however that most places will have long periods of rain-free weather.

There are two different temperature regimes today: cool air across the Great Lakes region and very warm steamy air to the south and east. This map shows the dividing lines between these zones from early this morning.

During the next few days, the high pressure area off the East coast is likely to expand westward. This will involve warming aloft and should lessen the amount of thunderstorms. The cool air should gradually erode across the Great Lakes region, promoting some sunshine and higher temperatures later in the week. These changes are a bit subtle and the effects will not be uniform, so check back with us for the latest forecasts as we go into the holiday weekend.