Radar, 1:45 a.m. Friday

Heavy rain as shown on radar runs through metro Baton Rouge late Thursday and early Friday in advance of Hurricane Delta.

An unexpected round of heavy rain and storms pounded metro Baton Rouge overnight, dumping more than six inches of rain on an area likely to see several more inches of rain from approaching Hurricane Delta.

Around 1:30 a.m. Friday the National Weather Service office in Slidell said more than a half-foot of rain was recorded at Baton Rouge Metro Airport in six hours. More than half of that total fell in just two hours.

According to WBRZ-TV, a swath of four-to-six-inch rain totals spanned northern East Baton Rouge and southern East Feliciana parishes.

The NWS shared a radar estimate showing almost nine inches of rain falling near Zachary.

The heavy rain in Zachary, Central and the surrounding area caused the Comite River to rise rapidly too. A river flood warning was issued around 2 a.m., and forecasters warned that those who live by the river "be prepared for possible river flooding impacts (Friday).

The river is forecast to crest over 25 feet. Flood stage is 20 feet.

Red Stick Ready -- the city of Baton Rouge's emergency preparedness communication channel -- reported high water on several surface streets after midnight:

-- Silverleaf at Glen Oaks Drive

-- Entrance ramp Interstate 110 South at Scenic Hwy

-- Florida at North Acadian

-- Essen and Picardy

-- Choctaw between Lobdell and Airline

A flash flood warning until 4 a.m. was issued for much of the metro area.

The round of heavy rain was surprising with Delta still more than 200 miles offshore. Several more inches of rain are forecast Friday as Hurricane Delta is projected to make landfall around 7 p.m.

Hurricane Delta strengthened a bit overnight and continued on its crash course toward the Louisiana coast, packing max winds of 120 mph. A tropical storm warning is in effect for the Baton Rouge area.

The hurricane's rain bands on its east side prompted the NWS to place metro Baton Rouge under a Level 2 "slight" risk for severe weather. The NWS uses a five-level scale to rate the risk of severe weather.

Follow Kyle Whitfield on Twitter, @kyle_whitfield.​