UPDATE (4:45 pm): NWS-NYC has issued a Special Weather Statement for northern Fairfield and northern Westchester counties. “A strong thunderstorm will impact Fairfield and Westchester counties... At 336 PM EDT...National Weather Service Doppler radar was tracking a strong thunderstorm near Ridgefield ... or 9 miles south of Danbury... and moving east at 5 mph.

“Small hail...and winds up to 40 mph are expected with this storm. In addition...very heavy rain...with rainfall rates of up to 2 inches an hour is occurring with this storm. This could cause ponding of water on roadways...and minor flooding of poor drainage areas.”

* * * * *

A Flash Flood Warning has been issued by the National Weather Service in New York City for Fairfield and Westchester counties. It is in effect until 5:45 pm.

At 4:17 pm, “strong thunderstorms producing heavy downpours to the west of this area have weakened, but with up to 2 to 3 inches of rain observed since 3 pm significant runoff and flooding is still expected over the next hour,” according to NWS.

In addition, the National Weather Service in Upton, N.Y., has issued an Urban and Small Stream Flood Advisory for Fairfield County, along with Putnam County and Westchester County in southeast New York, in effect until 5 pm.

“At 302 PM EDT ...  a developing area of heavy showers and thunderstorms was nearly stationary across the area. Rainfall rates  of 1½ to 2 inches per hour have been observed with this activity,” according to that branch of the NWS. “Excessive runoff from these storms will cause flooding of urban areas ... highways ... streets and underpasses as well as other drainage areas and low lying spots. In addition ... small creeks and streams will flood quickly... possibly covering roads and flooding nearby low  areas,” the statement continued.