PROJECT ALERT NOTICE (NY) USGS high-flow measurements

Date: Sun, 26 Feb 2017 15:26:59 EST

Summary: Minor flooding in Upstate New York.

Minor flooding is occurring in Upstate New York since yesterday evening (February 25) as a result of 1.0 to 1.5-inches of rain and several inches of snowmelt. Ten USGS streamgages reached the NWS minor flood category in the upper Susquehanna R basin and tributaries to the Hudson R, Mohawk R, Delaware R, and Lake Champlain basins. Streamflows a​re ​decreasing at many USGS streamgages this afternoon​, although large streams and streams in northern New York continue to rise into the evening. ​Most stages are forecast to fall below NWS flood stage by Monday afternoon, except two USGS streamgages along the Black R in northern NY that are forecast to crest near NWS flood stage this evening thru Tuesday morning. The ice jam that resulted in minor flooding at the USGS streamgage along the East Br Ausable River at Au Sable Forks in northeastern New York broke apart early yesterday morning. The rapid snowmelt was a result of 3 consecutive days of record high temperatures for the date, month, and Winter season at several locations in New York.

A total of six USGS crews (11 staff members) from the Ithaca and Troy, NY office have made 20 high-flow discharge measurements yesterday and today for rating calibration. Additional follow-up discharge measurements are planned for tomorrow (February 27)&#8203;. &#8203;The approximate annual exceedence probability is 0.2 (<5-yr flood). All equipment is operating.