This video explains how this week's weather should unfold and gives some hints about next weekend.
When the weather headlines screamed about the Polar Vortex last winter, I told you that the polar vortex could be found on the weather maps year-round. The issue was how large it was and how it was oriented. This map shows the polar vortex at the 500 mb level last night (June 8, 2014, 8 p.m. ET). It was centered close to the North Pole and has a very limited extent (as we expect during the warm season).
Thunderstorms were widespread across the Midwest yesterday. This map shows the lightning strokes from 8 a.m. ET yesterday. Note how thunderstorms formed along the sea breeze boundary in the Carolinas.
...after all that, the point is that zone will be north of most of the eastern half of the country. It will be very warm to hot south of the jet stream. However, weakening cold fronts can advance south of the jet stream. then return north as the next disturbance in the flow approaches.
Yesterday, the temperature hit 92 at Newark, New Jersey, and 90 in Boston. The following map shows a northerly flow affecting the Northeast today, and so it will be noticeably cooler and less humid.
This map shows lightning strokes from 8 a.m. ET yesterday through 7:54 a.m. ET today. There was quite a bit of it in Utah, Colorado, New Mexico and Arizona. For the whole map, 156,172 lightning strokes were recorded.
Looking at the west-to-east upper air flow over New England well ahead of the storm, it seems like the hurricane should stay out at sea, However, as we look through the series of maps, we see the upper-air flow congealing into a strong eastern trough that helped the storm to come right up the coast instead of heading out to sea.
On this satellite picture, we can see the basically dry weather in the Eastern states. The cold front that will ease the midweek heat in the Northeast is shown by the band of thunderstorms in the Midwest. The thunderstorms may weaken and become more scattered as the front comes into the Northeast.