We have now entered a very unsettled weather pattern, which will remain in place through Monday. However the heaviest and steadiest rain will fall from the overnight hours tonight through much of the day Friday.
Above in the satellite picture, I drew out the developing pattern.
I’ll start off with the bubble of dry air I circled because that will be affecting our weather today. An area of Canadian high pressure over the Great lakes is trying to send a bubble of dry air down to our area, however, we have a stalling frontal boundary over the area, currently slowly moving through Central NJ , and will stall over Southern NJ by tonight. So that big band of clouds and moisture will stall and train from west to east today, especially south of NYC over central ad south NJ leading to overcast skies and showers ,if your north of Central NJ you will most likely see breaks in the clouds and if you’re in NW NJ, NE PA and CT you will have times of sunny skies. Highs today will be in the mid 60s to low 70s
We see a developing disturbance marked “evolving rainstorm ” over the Tennessee river valley, this disturbance will ride along the stalled frontal boundary, so clouds will increase by late afternoon over the NYC metro and later this evening over NE PA and CT . Lows tonight will be in the mid to upper 40s NE PA to low to mid 50s along the coast as we enter the cold side of front
The reason for the stalled boundary and this whole active and wet weather pattern is the battle between the sub tropical high pressure to the south and the Canadian high to the north, putting our area right in the middle of them along with a tight temperature gradient
We can see the front beginning to stall out on radar, with scattered showers training over southern NJ and we also see our developing disturbance with rain filing into western PA. This isn’t a particularly strong storm system, but its picking up Gulf of Mexico moisture
So I expect showers to fill into the area by midnight tonight, evolving into a steady rain by 2-4 am and remaining steady through 12-3 pm Friday, with heavy rain at times and embedded downpours . Showers will continue through the afternoon hours. Overall I expect 0.50-1.50 inches of rain throughout the area, heaviest rain looks to be over east PA through NW NJ and CT where 0.75-1.50 is likely, the least being over southern NJ where more in the way of 0.50-0.75 is expected.
We will be on the cold side of the front, so highs tomorrow will only be in the upper 50s to mid 60s , lows at night will fall into the mid 40s to low 50s
Saturday through Monday, the stalled front will linger over the area but with much weaker disturbances riding along it, so instead of steady rain, we will just keep the threat for scattered showers and cloudy skies in the forecast, highs in the upper 50s to low 60s over NE PA to mid to upper 60s along the coast and los in the upper 40s to mid 50s
Finally, Tuesday and Wednesday the Canadian high pressure will take control , with clearing skies and highs in the low to mid 60s interior to low 70s along the coast with lows in the mid 40s to low 50s
Thursday and Friday we will moderate ahead of a strong cold front as high pressure and a SW wind takes hold, with highs in the upper 60s to low 70s NE PA to mid to upper 70s elsewhere, with even some lower 80s possible over southern NJ
Friday night the cold front will come through with scattered showers and thunderstorms, then a much cooler air mass will moe in for next weekend, with highs in the mid 50s to mid 60s and lows in the mid 30s NE PA to mid 40s along the coast