A very moist atmosphere will remain in place through the weekend, leading to more downpours such as those early Wednesday morning.
Heavy Rain At Times
The atmosphere overhead is loaded with copious amounts of moisture from the Gulf of Mexico and Atlantic Ocean. A disturbance moved through the Finger Lakes early this morning and interacted with the tropical air mass to produce some very heavy rain.
Much of the region got over a half inch of rain since last night. Some areas that have been particularly hit hard by the drought, including Ithaca, got anywhere from 1-3 inches of rain. Here in Groton, I measured 2.40″ of rain- more than had fallen from June 28th through last evening!
This air mass will remain in place through the weekend. Temperatures will rise well into the 80s and even some 90s each afternoon, priming the atmosphere for more thunderstorm development. While severe weather is generally not expected, more localized torrential downpours will be possible. As much as two inches could fall in under an hour during thunderstorms any time from this afternoon through early Monday morning. The best chances for heavy rain will be during the afternoons, but Saturday and Sunday night look particularly wet at this point in time.
From Drought to Flooding?
There is some concern that the flooding risk could increase over the coming days, despite the recent drought. Too much rain too fast will cause excessive run off. The main flooding risk should be limited to urban and poor drainage areas. If the same areas get a couple of inches of rain day after day, more significant flash flooding could eventually become a concern. At this time, the chances for that happening are relatively low.
Widespread, significant flooding along the larger rivers of the region is unlikely.
While it is not ideal to get inches of rain all at once due to the run off, any heavy rain will certainly help with the drought situation. It is a fine balance between getting enough rain, and getting too much.
Hot and Humid
This tropical air mass will keep conditions hot and very humid for the next few days. The hottest day will probably be on Thursday, when many areas will push above 90 degrees. Upper 80s and a few 90s will be likely Wednesday, Friday and Saturday as well.
The combination of heat and humidity will lead to heat index values well into the 90s for many areas. Take precautions against the heat and humidity during the afternoon hours.