The saturated nature of the atmosphere in the Northeast and Mid Atlantic states has us living in a sponge and that sponge is about to get wrung to some extent in the form of heavy rain. Thunderstorms will develop this afternoon and these are the types of storms that are slow moving and can produce significant amounts of rain (several inches or more) in a short period of time. Flood Watches are posted over much of Upstate NY mainly east of Interstate 81 and south of Interstate 90. Watches continue downstate to include the Hudson Valley and New York City as well as Western Connecticut. Watches continue across much of New Jersey, the eastern half of Pennsylvania, most of Maryland Virginia and points south.
How this is going to work is that thunderstorms are likely to develop this afternoon and they will be locally heavy and slow moving. Rainfall forecasts are rather useless other than to say that some heavier thunderstorms can produce several inches of rain in a very short period of time. Not everyone sees flash flooding but the risk is area wide so it will be a matter of watching where storms form and what areas they pass over.
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