The main threat from this system is strong and damaging winds, said the Weather Service.
A severe thunderstorm watch, issued at 12:05 p.m., is in effect until 8 p.m. for Westchester, Putnam, Dutchess and Rockland counties.
Monday's storm activity could begin after 1 p.m. and produce gusty winds of up to 70 miles per hour and heavy rain and hail, upsetting an otherwise partly sunny and hot day with a high temperature around 90.
Showers and thunderstorms are even more likely early Monday evening, when gusty winds and heavy rain could produce up to a quarter of an inch of water, more in thunderstorms. The night's air will remain warm.
Tuesday will be a sunny day with a high around 85. The night skies will be clear, with things cooling down more than 20 degrees.
The sun returns Wednesday with seasonable air and a high between 81 and 83 degrees.
Skies will be clear overnight with the mercury around 65.
Thursday will be sunny and warm, with a high around 88.
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