November 15, 2020 High Winds, Severe Winds, and Water Levels

     On Sunday, November 15th, a very potent upper level trough and strong 160 knot jet streak resulted in a deepening surface low down to 980 mb moving northeast across the Great Lakes region. The wind field ahead of this trough was particularly intense with upwards of 120 knots at 500mb and 70 knots at 850mb.

     A warm front extending from the low had moved north across northern Ohio early Sunday morning between 5-8 AM EST. Widespread showers did occur ahead of the warm front, clearing out and becoming less widespread as the warm front progressed northeastward. Farther west in central Indiana, the cold front initiated a line of isolated to scattered showers, quickly congealing into a fully developed line of thunderstorms as it progressed eastward towards Ohio. Temperatures ahead of the front/thunderstorms were in the mid to upper 50s with dew points right around 50. It’s noted that the analysis data seems a little lower in sfc T/Td than actual observations by about 2-5 degrees in temperature and ~1-2 degrees in dew point. Analysis had a slim corridor of 100-250 J/kg of SBCAPE with the line of t-storms. Positive differential potential vorticity advection (from the trough) and 250-850mb differential divergence (from upper-level jet streak circulation) were very strong with the front and pointed to strong upper-level forcing. Frontogenesis was also very strong along the cold front from the surface to 850mb.

     The result was widespread, damaging wind gusts across the entire NWS CLE forecast area with the line of thunderstorms, and for several hours after the frontal/t-storm passage. Observed gusts of 60 mph+ were common with the highest gust being 79 mph at Lorain Harbor Lighthouse. Damage was widespread to trees, power poles, and roofs, and other miscellaneous items. There were also widespread power outages, with over 150k people out of the power. Some power outages lasted more than 2 days! Every county except Lucas was under a Severe Thunderstorm Warning at some point and more than half of the NWS CLE forecast area had a High Wind Warning.

     Strong southwest winds also occurred across Lake Erie, with sustained winds greater than 50 knots and gusts greater than 60 knots Sunday afternoon/evening. For this reason, the NWS issued a Storm Warning for the entirety of Lake Erie, something that hasn’t happened since the remnants of Hurricane Sandy impacted the area in 2012. Storm-force winds resulted in a powerful seiche event, with a 14 ft differential between Buffalo (133.5” above LWD) and Toledo (34.5” below LWD). This additionally resulted in very high water levels at Erie, PA, where water levels peaked at 91.6” above LWD that evening. This resulted in significant lakeshore flooding at Presque Isle State Park and lakeshore communities of Millcreek Township, where evacuations of several homes took place that evening.

Loop of observed wind gusts

Loop of Weather Prediction Center surface analysis