If you look at Lee now, in its position over the Sargasso Sea, you see clear evidence of shear and dry air inclusion that is hampering the now 100 knot storm. Also note that this hurricane is starting to recurve toward the north. The 0z numerical model runs shifted landfall targets a bit west, to either Calais ME or St. John NB on Saturday morning. But the GGEM scheme was at Dartmouth NS, which is also where the 6z GEFS cluster suggests Lee will be on September 16.
All of this is important for the reason that high wind and rain impacts in New England could be limited to Maine. Cape Cod MA cannot be ruled out. But given that the hurricane will undergo a quick transition to cold core status and -may- not make a jump to the left, the Maritime Provinces could be the hardest hit from Lee before it reaches far eastern Quebec on Sunday. The cool air drainage behind this feature will reach the Gulf Coast, but likely start to modify next week.
Now while the temperature forecasts look quite warm, measured against seasonal normals you will soon realize that in most cases, it will not be hot. Even in Texas and the Deep South, where it will feel like summer again, the values will be at least about 10 degrees lower than what was seen in the first week of September. A cooler regime in California will struggle to move past the Rocky Mountains. However, the longer term forecast guidance suggests more rain/thunder and lower temperatures over the southern half of the USA starting in the first week of October.