Friday 8:15 a.m.
Temperatures will stay in the 60s and 70s across New Jersey and Pennsylvania today, the coolest day so far this summer. Many areas from Chicago to New York City have had significant rain. Does this mean the over dry spell is over? Does this mean the heat has had it? No. Looking at the GFS ensemble forecast for the next 16 days in Philadelphia, today and tomorrow are the coolest days between now and Aug. 4. However, last night's run did not show temperatures returning to this week's extreme.
In terms of the drought vis a vis (as that really a term?) recent rain in parts of the drought-stricken area, I have these thoughts. 1. Where places got more than about a half inch of rain it was helpful for the short term for grasses and flower beds. Where rain was much heavier, a good part may have run off, but in the short term was helpful. 2. The key now is whether the rain is a one and one thing or the start of some new pattern that will cause more frequent rainfall in the future. If that turns out to be the case, the recent rain will be seen as the turning point. If new rain fails to materialize, then those areas will revert back to the same conditions that have worsened all summer.
This video looks at the weekend and early next week.
This pressure analysis shows the boundary between hot air to the south and cooler air to the north. You can see a few low pressure areas along the front, each increasing the rainfall as it approaches, then introducing some drying upon departure.
It does look warmer for the weekend, but every time the warm air tries to extend into New England it gets chopped down. There could be more showers at times Sunday and early next week as forest we can tell. If any forecast gives you a headache, why not take a friend's advice: Take two aspen; sequoia in the morning.
This map from 5AM ET shows the cold front that is continuing toward this Northeast and Middle Atlantic states. Temperatures stayed up in the 70s all night ahead of the front but it turned noticeably cooler after the front moved through.
The cold front that will cut off the heat will generate strong gusty thunderstorms as it moves southeastward today. The National Weather Service Storm Prediction Center highlights the most likely area for these severe thunderstorms today and tonight.
As the high pressure area in the Northeast moves away, the the southwesterly flow pattern will shift eastward. This means Wednesday could be the hottest day of the week from D.C. to Boston. A cold front will follow.
This is a satellite picture showing rather tame conditions off the South Atlantic coast at 7:45 AM ET today. The area is being watched for any signs of storm development.
When looked at this way, you can see two distinct flows in the East: one from the south with moisture, and one from the west that is dry. There is a problem, however: the model solutions evolve over time, and as we get closer to next Monday afternoon (the time the forecast maps are using), the lines and orientations will probably change.