We currently have a strengthening area of low pressure moving into the Eastern Great Lakes and the key factor to this whole rain event is beginning to happen, the trough is turning negative tilted which means it’s tilting from SE to NW
With the trough in place turning negative, winds are becoming SSE aloft and ESE at the surface due to high pressure to our NE, and a strong jet streak is forming to our west with rain and heavy rain forming along it, moisture transport from the Atlantic will help enhance rainfall. This strong jet will also lead to increasing winds that will become quite gusty this afternoon and especially tonight
There will also be a severe weather threat from NC NNW through VA, Baltimore , DC and into southern PA this afternoon through tonight with gusty winds , hail, VERY heavy rainfall, dangerous lightning and potential weak tornadoes!! The rest of the region will be left out due to the warm front remaining south.
From Philadelphia on north , heavy rain is the main threat and there will be imbedded thunderstorms, just not severe.
The band of rain to our west will intensify coming east due to that moisture transport and will swing ENE
Here is later tonight around 10 pm and moderate to heavy rain with imbedded storms are entering the area, and a line of strong to severe storms for our southern friends
That band will swing ENE through the area, the heaviest rain will fall from Eastern PA through NYC and Northern NJ because the strongest lifting will be moving ENE but further south they will have the ingredients for more thunderstorms
Winds at the peak of the storm between 10 pm tonight and 6 am tomorrow will be SE at 20-30 mph with gusts to 50 in thunderstorms and downpours as strong winds aloft could be pulled to the surface by heavy rain. In the severe storms in the DC and Baltimore area, winds up to 70 are possible!!1
My rainfall forecast
SE NJ will get the least as they wont get the storms or the strongest lift only 0.33-0.50 is expected here
For the Philly metro, SE PA and SW NJ I expect a general 0.50-0.75 inch with locally more in thunderstorms, storms could be strong in this area
NYC metro can expect anywhere from 0.75-1.25 inches locally more up to 1.50 in storms
And Finally From Central to Eastern PA through NW NJ and into Western CT a widespread 1-2 inches is expected , could be locally more as the strongest lift goes through these areas
HPC Rainfall Forecast