Here is today's video, taking a look at today and they changes to expect between now and late next weekend.
This morning's surface nap show the flows that is bringing warmer air to the Northeast 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
... the main upper air steering current moves eastward across the northern Plains, then dives southeastward toward the Middle Atlantic states. The core of this current defines the rim of the hottest weather and serves as a conduit for clusters of thunderstorms.
3. Hot air will be moving east from the Plains, reaching the major East Coast cities Friday and Saturday. This map shows the upper-air flow that will make this happen.
This map shows lightning strikes from 8 a.m. EDT yesterday until 7:20 a.m. EDT today. A concentration of thunderstorms can be seen in the Midwest ahead of the cold front.
At 10 a.m., it was already 85 in Boston and 90 in Newark, N.J. The afternoon will be quite hot as weak cold front approaches. It should become a <u>little</u> more more comfortable this weekend.
Subtle and sometimes hard-to-detect boundaries within the heated air mass help with shower and thunderstorm development and organization. There is no one well-defined cold front.