Northeast US winter storm
GOES-16 (GOES-East) Mid-level Water Vapor (6.9 µm) images with plots of hourly surface weather type (above) showed the formation of a well-defined cold conveyor belt that moved westward across parts of the Northeast US during the 01 February – 02 February 2021 period. This moist airstream helped to enhance snowfall rates, with 2-4 inches per hour occurring at some locations. Storm total snowfall accumulations were as high as 36.1″ in Pennsylvania, 35.5″ in New Jersey, 25.6″ in New York, 24.0″ in Massachusetts, and 19.0″ in Connecticut.Another feature that played an important role in enhancing/prolonging heavy snowfall rates was a TROWAL — appearing as a tongue of higher Equivalent Potential Temperature within the 850-700 hPa layer, just north of the surface occluded front — moving inland and feeding moisture into the southern edge of the cold conveyor belt seen on GOES-16 Water Vapor imagery (below).
Updated January 30-February 2 snowfall reports based on reports received as of 6 pm Tuesday. Here are the latest highest totals in each state (1 of 2).
PA – Nazareth 36.1″
NJ – Mount Arlington 35.5″
NY – Fishkill/Saugerties 25.6″
MA – Lowell 24″
WV – Terra Alta 22.1″ pic.twitter.com/unxodO5ccS— NWS Eastern Region (@NWSEastern) February 2, 2021
1-minute Mesoscale Domain Sector GOES-16 “Red” Visible (0.64 µm) images with 5-minute plots of Derived Motion Winds (below) revealed a mesoscale circulation just south-southwest of the analyzed location of the surface low — the majority of these wind vectors had height assignments within the 900-990 hPa range, indicating that the circulation was located above the surface. The highest DMW speed was 36 knots.