Long Island Weather: Severe Thunderstorm Watch In Effect; Heat Index Hits 100 Degrees

Thursday is the quintessential hot, stormy summer Long Island day. Temperatures are in the 90s, and the heat index (how hot it really feels with humidity levels factored in) hit 100 degrees before noon on parts of the island. We will also be dealing with some potentially severe thunderstorms.

A severe thunderstorm watch is in effect for the island until 9 p.m. Thursday.

"There is a slight risk for severe thunderstorms from this afternoon into tonight," the National Weather Service says in a hazardous weather outlook. "The main threat is from damaging winds. There is also a chance for localized flash flooding from late this afternoon through tonight."

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It was 92 degrees at 10:56 a.m. at Long Island MacArthur Airport, matching the daily record high for the day.

More rain and thunderstorms are on the way Friday before things clear up for the weekend.

A flash flood watch will be in effect for the entire island from 2 p.m. Thursday until 6 a.m. Friday.

"Three inches or more of rain will be possible where the heaviest and most persistent storms occur, leading to flash flooding," the flood watch says.

The full forecast:

Thursday Afternoon- Showers and thunderstorms likely, mainly after 5pm. Some storms could be severe, with damaging winds and heavy rain. Partly sunny, with a high near 92. Heat index values as high as 100. Southwest wind around 10 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Thursday Night- Showers and thunderstorms. Some storms could be severe, with damaging winds and heavy rain. Low around 69. Northeast wind around 7 mph. Chance of precipitation is 80%. New rainfall amounts between 1 and 2 inches possible.

Friday- Showers likely. Cloudy, with a high near 73. Northeast wind around 8 mph. Chance of precipitation is 60%. New precipitation amounts between a half and three quarters of an inch possible.

Friday Night- Scattered showers and thunderstorms. Cloudy, with a low around 68. East wind 5 to 8 mph. Chance of precipitation is 50%.

Saturday- Patchy fog before 9am. Otherwise, cloudy, then gradually becoming mostly sunny, with a high near 84. Northwest wind 7 to 9 mph.

Saturday Night- Partly cloudy, with a low around 69.

Sunday- Sunny, with a high near 86.

Sunday Night- Partly cloudy, with a low around 70.