Looking at tonight’s radar animation, one can easily see where the axis of heaviest rains are setting up for the upcoming event, resulting from a stationary front just to the west of our area, and the remnants of tropical storm Lee, which should last through Thursday:
Stratiform rains are seen just to our west centered on a line from Parkersburg, WV, to State College, PA, to Binghamton, NY. However, more tropical like showers and thunderstorms are developing to the east, which includes the Delaware and Lehigh Valleys:
This will result in flash flooding in areas which were innundated with rain over the past month. It’s no surprise that the HPC has drastically increased the precip amounts for the area, especially to the west:
As a result, I expect 3-5 inches areawide, with isolated amounts to 7 inches, more to the northwest, and less to the southeast.
The silver lining in all of this is this front and the remnants of Lee should keep Katia, now a major hurricane (and may I add likely a strong category 3 storm in my opinion given the satellite appearance), at bay and threatening only the outer banks and Cape Cod with any direct effects. There is the outside chance that the Fuijwara effect comes into play, which is what last night’s Canadian was showing, and pulls the storm into the coast, but I DO NOT see that happening right now (typically the stronger of the two cyclones pulls the other in, not the other way around).
I had to include this loop and static image below showing what a true major hurricane looks like as thunderstorms rapidly develop and encircle the eyewall of Katia: