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Overview

On the morning of Wednesday, a stout high pressure was firmly in place over the Canadian Maritimes with a strong ridge axis extending down the East Coast. Over the central United States a strong upper level trough developed as the Polar Front Jet dove south into the Lower MS Valley. A strong surface cold front developed and strengthened as it slowly made an eastward progression over the next 48-72 hours. Strong southerly flow ahead of the front allowed for heavy rainfall, a wintry mix, and heavy snowfall to be reported all the way from Texas northeast to Maine. This setup brought ample moisture northward into the Upper Ohio Valley Region.

A moderate to heavy rainfall developed over the region by Wednesday night. With the area already under 3 to 6 inch snowpack (more in the mountains),  and ice well formed along the rivers and creeks in the north from arctic air entrenched over the region for an extended period, a flood threat was evident in addition to the dangerous amounts of freezing rain and snow expected. Moderate to heavy rain continued through the day on Thursday as the front slowly progressed east  as rain changed over to freezing rain. The mentioned ridge over the East Coast impeded the eastward progression as the front did stall at times keeping freezing rain over the same locations for a dangerous extended period of time in some instances. This also meant that heavy rainfall over the same locations for a period of time as well. This indeed led to the flooding of low lying areas and along creeks and streams. The ice build up along rivers led to ice jams in some locations causing flooding in these locations as well. One of these instances was at Fish's Creek in Marshall County WV. Another event occurred along the Muskingum River and also along the Conquessening River. 

The prolonged period of freezing rain led to heavy ice accretion on trees causing them to fall over powerlines. Power outages to homes and businesses climbed into the tens of thousands in Pennsylvania, West Virginia, and especially into Ohio where the heaviest amount of freezing rain occurred. The northern Pennsylvania counties along I-80 changed over to snow first where some locations received 6 to 10 inches. By Friday afternoon, a strong push of arctic air from the northwest allowed the front to finally push through the area with snow showers lingering across the Upper OH Valley on Friday evening before finally coming to an end. In addition, the mentioned push of arctic air brought temperatures into the single digits for the weekend keeping the snow and ice around for a longer period of time. The multifaceted threats of this winter event led to a wide range of impacts and some broken daily rainfall records at several locations. 

Image
Ice Accretion on Weather Sensor at the National Weather Service Office in Moon Township. 

Credit: Jared Rackley

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