Tuesday 9 a.m.
Today's regional forecast video:
This lightning map shows most of it occurred in the Southeast and over the Southwest mountains, which is typical, and off the California coast, which is unusual in August.
This upper air map shows (1) there is no strong heatwave ridge over the Midwest or Northeast any more and (2) a broad trough populated with smaller disturbances will move from the Mississippi Valley to the Appalachians by Sunday.
On this satellite picture, we see the plume of moisture advancing northeastward from the Ohio Valley.
In this picture, the sun had set as seen from the ground. However, sunlight was able to light up the clouds from below to create this look outside my home:
Now, drier air has arrived, and most of the Northeast will have abundant sunshine today and tomorrow.
A front that will usher in slightly less humid air for the Northeast tomorrow will trigger locally strong thunderstorms today.
Thunderstorms will continue to erupt near the northern edge of the heatwave, enhanced by a series of disturbances rippling along in the upper air flow. This is the NWS Storm Prediction Center's severe thunderstorm outlook for today