It would be wise to keep those umbrellas and raincoats within arm’s reach due to a flash flood watch in effect from tonight through Tuesday evening.

The National Weather Service issued the flash flood watch as heavy rain associated with Tropical Storm Isaias is expected to move through the area.

Widespread amounts of 4 to 6 inches are forecast with locally higher totals possible.

A flash flood watch means that there is the potential for flash flooding, which can be life-threatening. Heavy rain is expected to occur over a short period of time. Rapidly rising floodwaters may quickly inundate roadways and areas of poor drainage. Streams and creeks could leave their banks, flooding nearby properties.

Exactly how much rain depends on the track of the storm, according to Amanda Wagner, a meteorologist with the National Weather Service.

“This evening, tonight and tomorrow, looking at heavy rain for the southeastern counties, kind of a sharp line 3-plus inches on the east side of the I-81 corridor; still depends on where the track of storm goes, could see maybe 4-plus inches, over 5-6 inches, too,” Wagner said. “We are looking at some flash flooding, river flooding, too.”

Wagner provided a glimpse of what things could look like in the northeast.

“Still expecting some high volumes of rain, 2-4 inches with higher amounts locally,” she said. “The further east you go and closer to Philly, higher amounts and stronger winds; I don’t think we’re looking at anything crazy with winds.”

Wagner offered some important safety tips for motorists to follow.

“One of the biggest things is don’t drive through flooded roadways; if riverbanks flood over, or if there’s heavy rain, flash flood happens,” she said. “It only takes a few inches to move the vehicle.”

But that isn’t the only safety precaution to follow, Wagner said.

“It never hurts to have an emergency kit on standby, monitor your area forecast because the forecast changes all the time,” she said. “Just keeping up to date of what happens in your area.”

Here is the latest forecast:

Today is expected to be partly sunny, with a high near 82. Tonight is when things could get interesting with a chance of showers and thunderstorms, then showers and possibly a thunderstorm after 8 p.m. Some of the storms could produce heavy rainfall, with new rainfall amounts of between three quarters and 1 inch possible.

Tuesday calls for a high of 74, with showers and possibly a thunderstorm, and some of the storms could produce heavy rainfall. New rainfall amounts between 1 and 2 inches are possible. There’s a chance of showers and thunderstorms in the evening, with new rainfall amounts of 1 and 2 inches possible.

Things should clear up on Wednesday, which figures to be mostly sunny with a high near 80 and just a slight chance of showers and thunderstorms.

Thursday will be mostly sunny, with a high near 81.

Friday will be partly sunny with a high near 80, with thunderstorms possible after 2 p.m., and a chance of thunderstorms before 8 p.m.

There’s a chance of showers and thunderstorms Saturday, which is expected to be partly sunny, with a high near 83, along with a chance of thunderstorms in the evening.

Sunday will be mostly sunny, with a high near 85.