Thursday, 31 August 2023
Boundary Waters (Hyatt Regency Minneapolis)
Between 1 Feb 2022 18 UTC and 6 Feb 2022 00 UTC, a very slow-moving cold front moved across the Midwestern and Eastern United States producing snowfall accumulations of 6-12 inches or greater across a wide swath extending from Oklahoma to Maine. The cold front was associated with a stream of moisture flowing from SW to NE ahead of, and over the front, as seen in the high values of integrated water vapor content present at the time of the NASA IMPACTS research flights of the NASA P-3 and ER-2. IMPACTS sampled the snowstorm associated with the cold front twice with both the P-3 and the ER-2. In the first flight over the Midwest, the ER2 flew 2 flight legs, one northbound and one southbound, then returned to base, while the P-3 flew 7 flight legs at 5 altitudes, all above the melting level as seen in the radar data. In the second flight, the P3 and ER2 flew a lawnmower pattern across the NE U.S., the P-3 sampling 6 altitudes in eight flight legs. In this poster, I present a synoptic and radar analysis of this storm and relate the frontal structure and mesoscale flow to radar characteristics and large ice particle characteristics and spectra. On the first flight, the storm was characterized by cloud top generating cells extending from temperatures of -35°C to -64°C and rapid particle growth at the -35°C level. The ice particle spectra were sampled in 4 flight legs across the front, the top leg from -28 to -20°C and the lowest leg from -15 to -3°C. On the second flight, the cloud was sampled in 7 legs between -21 and -1°C. The reflectivity structures evident from the W-band, Ka-band, and Ku-band radars will be compared to large particle spectra measured on these flight legs.

