7:00 AM (Thursday) | ***Severe thunderstorm threat later today/tonight and then a break in the action for Friday, Saturday, Sunday***

6-Day forecast for the Philadelphia metro region

Today

Mainly cloudy during the morning hours, some sun can poke through the clouds this afternoon, quite warm, very humid, a couple of showers or some drizzle this morning, showers and thunderstorms likely by mid-afternoon, some of the storms later today can be severe, watch for localized flooding, highs in the low-to-mid 80’s

Tonight

Evening showers and thunderstorms likely, some of the storms can be severe, watch for localized flooding, remaining mainly cloudy after midnight, mild, muggy, lows in the mid 60’s

Friday

Partly sunny, windy with gusts to 30 mph, more comfortable with lowering humidity, lingering showers are possible early, upper 70’s for afternoon highs

Friday Night

Mainly clear, breezy, cool, mid 50’s for overnight lows

Saturday

Mainly sunny, comfortable, upper 70’s

Sunday

Mainly sunny, warm, lower 80’s

Monday

Partly sunny, warm, chance of showers and thunderstorms, mid-to-upper 80’s

Tuesday

Partly sunny, warm, chance of showers and thunderstorms, mid-to-upper 80’s

Discussion

A tremendous amount of rain fell late yesterday and last night across southeastern PA, east-central PA and much of southern and central NJ with nearly four and a half inches recorded at Philly Intl Airport. All of this was as a result of extremely slow-moving shower and thunderstorm cells in an overall weak wind field in the atmosphere along with a tropical air mass firmly entrenched in the region. For today, an unusually strong low pressure system for this time of year will move towards northwestern Pennsylvania and an associated strong surface cold front will slide towards the I-95 corridor. At the same time, a powerful wave of energy in the upper part of the atmosphere will move over the Mid-Atlantic region. As a consequence, there can be an outbreak of severe thunderstorms from later this afternoon into tonight that could impact the DC-to-Philly-to-NYC corridor with damaging wind gusts, hail and perhaps even a few isolated tornadoes and the localized flooding threat will continue as well in any downpour. Once the strong cold front clears the coast by early tomorrow, the threat for rain will wind down, humidity will drop noticeably, and the winds will pick up from a northwesterly direction gusting to 30 mph or so. High pressure will build into the area later tomorrow and it may just stay in control for most of the upcoming weekend, but more showers and thunderstorms are possible around here by Sunday night and Monday.

Meteorologist Paul Dorian
Perspecta, Inc.
perspectaweather.com