HEAVY RAIN WEDNESDAY

The rain developed about 1 PM and stayed mostly in Philadelphia and areas south.
Wed 07:32 AM Update — The rain last night did stay to our north. Last night’s models have backed off on the extreme rain totals for this afternoon. 0.75-1.5 inches looks to be the generalized amount later this afternoon.
Tues 10:44 PM Update — Tonight’s models just becoming available vary in the location of the first batch of rain tonight (maybe staying north of the immediate area) and tomorrow afternoon (which may be later in the afternoon or early evening and mostly from Philadelphia and to its south.) The models seem to vary with the location of the stalled front.
Heavy rains are expected Wednesday in the Philadelphia area.

A frontal system will stall near our area. Two separate rain events will move through.

The first disturbances will move in before daybreak, about 3-6 AM Wednesday morning with heavy rain.

Another disturbance will move through during the mid to late afternoon. The afternoon disturbance will bring the heaviest rains. 

High moisture levels (“PWAT” or “precipitable water”) along with strong dynamics and slow storm motion due to light winds will result in localized areas having 1-3+ inches of rain.

The latest Model Blend (NBM)  depicts the localized nature of the rains tomorrow.  (The locations shown with the heaviest rain should not be taken literally; almost every area will have some heavy downpours. )

NBM precip forecast for Wednesday 5 PM

SUNDAY FORECAST UPDATE

Sun 12:59 PM Update —This morning’s models are back with isolated/scattered showers this afternoon.

Sun 08:51 AM Update — This morning’s early models have backed off on the scattered showers this afternoon.

We didn’t see any showers in the area today, but we did have that mix of sun and clouds.

The forecast is mostly on-track for Sunday. High temp 88.1° sd 2.1° (high spread). It will be more humid than previously forecast with dew points 69-70°.

Several models show an upper air disturbance moving through between 3 and 6 PM, near Philadelphia and slightly south.  A brief shower or thunderstorm is possible.

Weather… and Other Things 'Up in the Air'