At 11:56 a.m. on Wednesday, the National Weather Service issued an updated flood watch valid from 3 p.m. until Thursday 3 a.m. for Western Chester, Eastern Chester, Western Montgomery, Eastern Montgomery,

Monday is a NEXT Weather Alert day in the Philadelphia region for tropical downpours and an elevated flash flood risk. As a cold front approaches the area, widespread showers and storms will develop in the afternoon, evening and overnight hours. Any storm could train over the same areas for an hour or more.

So observes Sarah Johnson, the warning coordination meteorologist at the National Weather Service office in Mount Holly, which yet again has posted a flash flood watch, this one from 2 p.m. Monday until 2 a.m Tuesday.

A flood watch was issued by the National Weather Service on Sunday at 1:44 p.m. valid for Monday between 2 p.m. and 11 p.m. for Western Chester, Eastern Chester, Western Montgomery, Eastern Montgomery,

A flood watch is in effect in Philadelphia and its surrounding area for Monday. FOX 29 Meteorologist Kathy Orr breaks down what to know.

The NWS has issued a Flood Watch for parts of Pennsylvania due to heavy rain forecasts, with potential flooding and thunderstorms expected throughout the week.

FLOODED ROADSA band of over 3" of rain over a short period of time has fallen along Route 1 through southern Chester and Delaware Counties leading to numerous reports of flooded roadways and stranded vehicles. Avoid driving in this area. Flash flood warnings are in effect. pic.twitter.com/dh9TXhNN1c

The National Oceanic and Atmospheric Administration Storm Prediction Center had Philadelphia and most of Pennsylvania and New Jersey under a severe thunderstorm watch. The weather service said the amount of energy available to ignite storms Tuesday was near or above the “extreme” level.