Just four weeks after remnants of Hurricane Beryl left central New York with heavy rain and tornadoes, Tropical Depression Debby — the slowed remnants of a category one hurricane — brought Ithaca heavy thunderstorms and flash flooding.
As a tropical storm, Debby initially brought lashing winds and pounding rain along Florida’s Gulf Coast the weekend of Aug. 3, leaving hundreds of thousands without power. The storm continued to strengthen, becoming a hurricane — a tropical cyclone with sustained winds 74 mph or greater — late on the night of Aug. 4 as it began its northeastern turn into Florida’s Big Bend Region.
After leaving the Gulf Coast of Florida, Debby continued its onslaught onto the coasts of the Carolinas. The cyclone moved back over open waters in the Atlantic, restrengthened and made a second landfall along the South Carolina coastline early the morning of Aug. 9 as a tropical storm — a tropical cyclone with sustained winds between 39 and 73 miles per hour. Along with heavy rainfall and storm surge, Debby also produced four tornadoes in the Carolina region, a common consequence of tropical systems.
After its second landfall, Debby continued northward towards the Mid-Atlantic and Northeast, prompting predictions of excessive rainfall in Ithaca on Aug. 9.
Rain engulfed central New York early Aug. 9 and persisted through the middle of the day. The National Weather Service at Binghamton issued a flash flood warning for the central Finger Lakes region, including Ithaca, from 12:30 p.m. to 6:30 p.m.
Excessive rain exacerbated already wet conditions in Ithaca — the weather station at Game Farm Road in Ithaca saw three times its average rainfall during the first 10 days of August. Consequently, the ground was already saturated with water, and the various creeks and streams around Ithaca were running higher than usual, making the area even more prone to flooding.
Total rainfall observed from the remnants of tropical storm Debby in the National Weather Service Binghamton forecast region. Photo courtesy of National Weather Service Binghamton.
Ithaca observed 2.3 inches of rain, and several rivers and streams in and around Ithaca exceeded their flood stages — the minimum height above which water level becomes dangerous — on Aug. 9. By the next morning, all rivers returned to below their flood stage as conditions began to dry out quickly.
While Ithaca’s flooding remained manageable, other regions in the Northeastern U.S. were less fortunate. The worst of the flooding on Aug. 9 occurred in north-central Pennsylvania. In the town of Westfield, PA, numerous structures and vehicles were swept away from raging flood waters as nearly five inches of rain fell.
In addition to the flash flood risk, Debby also posed a tornado threat for Ithaca, though much less severe than the prior month’s tornado threat from Beryl. Tornadoes most commonly occur in the northeast quadrant of a tropical system, where wind orientation allows for the additional “spin” in the atmosphere necessary for tornado development. While Beryl’s northeast quadrant passed over Ithaca and much of central New York, Debby tracked eastward, thus largely avoiding Ithaca. Still, a single tornado was reported and confirmed in Ulster, NY on Aug. 9.
The forecasted cone from the National Hurricane Center on Friday, Aug. 9, showing the storm’s center cutting through central New York. Image Courtesy of the National Hurricane Center.
With much of the hurricane season still ahead, Debby may be just the first of several tropical systems to impact the Atlantic and the U.S. As the peak of a projected above-normal hurricane season nears, residents along the East Coast, including Ithaca, should stay vigilant of potential impacts.
William Cano, Ronald Geiger and Jack Halberstadt are Sun Contributors and can be reached at [email protected], [email protected] and [email protected].