* Flash flood watch Friday morning through evening for entire metro region *

Radar & lightning:Latest D.C. area radar shows movement of precipitation and lightning strikes over past two hours. Refresh page to update. Click here or on image to enlarge. Or see radar bigger on our Weather Wall.

Deep tropical moisture from tropical storm Andrea is streaming northward, and brings the likelihood of heavy rain at times Friday. Lighter rains envelop the region overnight.

Through Tonight: Rain increases in coverage from southeast to northeast this evening, with most areas wet by 7-8 p.m. The rain that falls overnight is generally light to moderate, with about half an inch or so falling by morning. Low temperatures are in the mid-60s with winds from the east around 10 mph.

Tomorrow (Friday): Rain is about certain and it may well be very heavy at times, particularly from mid-to-late morning through early-mid evening. Rainfall totals by evening (including tonight’s rain) should be in the 1-3 inch rain, with locally heavier amounts. Take a moment to clear drain pipes and gutters as needed. Localized flash flooding is a strong possibility, particularly in those areas that typically flood during heavy rain events. High temperatures are in the low-to-mid 70s, with generally light winds…although a few stronger gusts (20-35 mph) are possible in heavy rainbands and possible embedded thunderstorms.

More details: What tropical storm Andrea means for Washington, D.C. area; flash flood watch

See David Streit’s forecast through the weekend. And if you haven’t already, join us on Facebook and follow us on Twitter . For related traffic news, check out Dr. Gridlock.

Andrea update: As of 5 p.m., Andrea is making landfall in northern Florida (see wind diagram in right panel in image below). It is spreading a massive plume of moisture up the East Coast (see left panel in image below), where it’s interacting with a frontal system. Flash flood watches (shaded in green in the middle panel in image below) span from Florida to Maine.

Look at how much rain is forecast from Florida to Maine through Saturday night by the National Weather Service: