Philadelphia woke up to a cool, gray start on Saturday, May 9, with temperatures sitting in the mid 50s and showers already edging into the region. Expect a soggy stretch for much of the day. Rain is likely between about 8 a.m. and 2 p.m., with showers and a few thunderstorms becoming more widespread in the afternoon. A few of those storms could pack a punch. Gusty south to southwest winds may reach around 20 to 25 mph, and once the rain eases overnight, patchy fog could develop.
Timing and What to Expect
According to the National Weather Service Mount Holly, widespread showers should move through late Saturday morning into the afternoon, with the highest rain chances between about 8 a.m. and 2 p.m. The office puts precipitation chances near 80 to 90 percent for much of the city. Most spots can expect around a tenth to a quarter of an inch of new rainfall, with locally higher totals in thunderstorms.
Forecasters have also highlighted a marginal severe storm risk for parts of the area, meaning isolated storms could produce damaging wind or hail, mainly along the I 95 corridor this afternoon. In other words, most storms will just be wet and noisy, but a few could briefly turn stronger and disruptive.
Coastal and Marine Concerns
A Small Craft Advisory is in effect from 10 a.m. Saturday through midnight for Atlantic coastal waters from Manasquan Inlet southward and the lower Delaware Bay. South winds are expected to increase to 15 to 20 kt with gusts of 25 to 30 kt, or about 30 to 35 mph, and seas building to 3 to 5 feet.
For boaters, that means rough going on open water. Anyone planning to head out in a small vessel should think twice and either avoid small craft altogether or delay trips until conditions calm down tonight.
Tonight Into Sunday
Showers and storms should taper off late Saturday. With light winds and plenty of leftover ground moisture, areas of patchy fog could develop overnight as temperatures drop into the low to mid 50s.
Sunday, May 10, brings a big warm up, with highs near 80 possible. Early patchy fog should give way to a mix of clouds and sun, but another round of showers and thunderstorms is possible later in the day. A front moving through Sunday night into Monday looks set to deliver a more organized batch of showers and thunderstorms.
Behind that front, Monday turns cooler, with highs in the low 60s and several more chances for rain lingering into next week.
Plan Ahead
If you have outdoor plans on Saturday afternoon, it is smart to move them earlier in the day or line up an indoor backup. Expect a wet commute, some reduced visibility at times, and the potential for brief heavy downpours.
Mariners should take the Small Craft Advisory seriously, skip small boat trips until conditions improve, and check for updated forecasts before heading out. For more on how this pattern developed and what forecasters were seeing earlier, check out our morning drizzle forecast.
