Another Update 11:42 pm: Some models don’t have us getting out of the 50s on Sunday.
Tonight’s models have trended towards last night’s NAM, which had the warm frontnot making it into Philadelphia.
Weak low pressure developing near the Delmarva coast will maintain a cooler east to northeasterly flow for Sunday. Low clouds, scattered sprinkles are possible in the morning. Some brightening skies possible, but not a certainty in the late afternoon.
While cloudy, it should be possible to get exercise outdoors.
At one point, thunderstorms seemed possible about 4-6 pm, but that looks unlikely now. Highs near 60 (instead of the mid 60s-70 that was previously forecast)..
Brief Update: Rain and showers are expected throughout Saturday. About 0.5 inches of rain expected.
There is still uncertainty about some aspects of Sunday’s forecast.
This morning’s models have light scattered showers in the morning Sunday.
For Sunday afternoon, the GFS has the warm front moving through about 3-5 PM with a significant upper air ‘short wave’ moving through. Showers and thunderstorms are likely with this potent area of localized vorticity—
GFS showing short wave, (dip in the blue line) (arrow) in the upper air flow
The energy for the most thunderstorms, as measured by the parameter called CAPE (convective available potential energy) is indicated in the darker shades of orange below; notice it is mostly south and west of our immediate area—
GFS CAPE forecast for Sunday at 4 PM
It’s important to note that the NAM model and NAM-NEST models suppress this wave to our west and south and keep an easterly flow until 7 -8 PM, reducing the chance of thunderstorms here and delaying the warmup somewhat.
We’ll see how this unfolds with future model runs.
