As heat and humidity build in CNY, we're hearing about a dangerous heat index by the end of the week, but what is a heat index?

NWS says CNY could be in for excessive heat on both Friday and Saturday as maximum heat indices each afternoon in the valleys reach between 100 and 105 degrees. Heat indices in the mid to upper 90s may linger into Sunday.

US National Weather Service Binghamton NY

As the tropical moisture surges across the region, we'll feel the oppressive summer heat and humidity and get little relief with occasional showers and thunderstorms. As you see above, the heat index will be dangerously high and unsafe for those who have no way to cooling off.

NWS describes the Heat Index (HI) or the "Apparent Temperature" as an accurate measure of how hot it really feels when the Relative Humidity (RH) is added to the actual air temperature. 

So if it feels like it's 100 degrees, then that's probably the heat index. The most important thing to do in heat like this is to stay hydrated - and that means drinking water, not soft drinks or alcohol because both will work to dehydrate you.

CNY will see remnant circulation from Barry. With the influx of tropical moisture, we could see about 2" of rain. We're expecting storms with torrential downpours. There's a concern for locally heavy rainfall that could lead to poor drainage or isolated flash flooding.