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Overview

Low pressure began to develop along the coast of Georgia during the morning of 1/31 while ~1042mb Arctic high pressure was centered over the Plains. A piece of that high had already built over the northern Mid-Atlantic, ushering in very cold but also dry air from the N-NNE to the local area. An upper low then dove from the TN Valley to South Carolina during the day on 1/31 before becoming negatively tilted as it moved offshore of the South Carolina coast during the night of 1/31 and morning of 2/1. This allowed for the weak surface low to rapidly deepen about 100-150 miles off the Carolina coast from the afternoon of 1/31 to the morning of 2/1. In fact, it deepened an astounding ~30mb from the morning of 1/31 to morning of 2/1. An area of snow associated with lift from the upper low impacted western VA and west-central NC during the morning and through the day on 1/31. This area of snow largely missed the local area to the southwest. Another area of precipitation associated with the rapidly deepening coastal low broke out over eastern NC (initially south of our area) during the morning of 1/31. Temperatures were in the upper teens with very low dew points during the morning of 1/31 across the AKQ CWA, and there was a well-defined dry layer between 900 and 800mb that would have to be overcome before any precipitation reached the ground (see mesoanalysis section for details). Interestingly, there was widespread lift from 700-500mb across central and southern portions of the CWA through the event, but that low-level dry air proved to be very hard to overcome. Snow eventually overspread far southern VA and NE NC during the afternoon and evening, but struggled to make it north of a Lunenburg-Wakefield-Norfolk line. And even in southside Hampton Roads (including Norfolk and Chesapeake), that dry layer would remain there for several hours before snow finally started accumulating around 7-8 PM (there were radar echoes here for much of the afternoon as snow sublimated before reaching the ground). Also, mesoscale analysis noted that the main mid-level frontogenesis zone (in the DGZ), remained across NE NC, with sinking motion across much of SE VA on the cold side of the frontogenetic circulation. Snow quickly ended across SE VA by midnight but persisted across NE NC (especially near the Albemarle/Currituck Sounds) through 4-7 AM on 2/1. 

The only part of our CWA to see 6"+ amounts was NE NC, where near blizzard conditions were observed from Elizabeth City to the coast. Winds gusted to 45-55 mph out of the north during the latter part of the event thanks to a tightening pressure gradient on the back side of the low. Ultimately, the swath of 6"+ amounts ended up 30-40 miles south of where a lot of the global models and ensembles were forecasting it to be as that dry air proved very hard to overcome.

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