A mid-December winter storm brought significant snowfall to the northeast US, including totals over 40″ (Fig 1)!
GOES-East Water Vapor imagery from Sunday evening through Thursday morning captured the evolution of the shortwave trough, a key ingredient to the major winter storm, across the nation (Fig 2). An overlay of RAP analysis fields helps one to correlate the synoptic scale features apparent in the water vapor imagery with those in the upper level analysis. For example, the sharp temperature gradient on the southern periphery of the wave (cold on south side, warm on north side) represents the location of upper level jet winds. Additionally, the shortwave is easily identified given the cyclonic circulation apparent in animations, but also via the couplet of warm/dry descending air and cool/moist ascending air
A IR-VIS/IR Sandwich transition procedure from GOES-East shows the evolution of the system along the east cost during the evening of the 16th into the morning of the 17th, with the surface low circulation becoming exposed during the daytime (Fig 3). The overlay of RAP analysis MSLP adds quantitative information about surface pressure trends and .
GLM imagery captured a few instances of lightning within areas of ongoing snow (thundersnow) during the overnight hours, including in W PA and SE PA early in the evening/animation, and then in NH by early morning and late in the loop. Abundant lightning was detected with thunderstorms off the coast along the front (Fig 4).
During the day of the 17th, numerous interesting features could be diagnosed in the GOES-East Day Cloud Phase Distinction RGB imagery (Fig 5). Surface features in clear sky areas include melting snow in Maryland, snow cover extent, and snow cover over forested areas vs that over non-forested areas. As for cloud features, low clouds and fog (liquid clouds), including over snow, can be differentiated from high/glaciated clouds and potential areas of snowfall. The precise location of the surface low can be tracked, along with nearby and abundant gravity waves which can imply turbulence. Further, individual/narrow snow bands are diagnosed across E NY, CT, RI, and MA.
A comparison for one time period between the DCPD RGB and MRMS composite reflectivity demonstrates the ability of the RGB to capture individual snow bands, which can be especially valuable as a compliment and in the absence of radar (Fig 6).
GOES-East 1-min mesoscale sectors were centered over the storm system during it’s evolution. One-minute visible imagery provided a detailed (spatially and temporally) view of the surface low circulation and adjacent cloud top gravity waves as it moved offshore (Fig 7).
Bill Line, NESDIS and CIRA
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