RAMMB Satellite Case Studies

A Moderate Intensity LES Case From January 16th, 1997

The LES event covered by this imagery affected both the upper and lower portions of Michigan. This case was chosen because of the availability of super-rapid scan operation (SRSO), 1-minute interval, imagery collected during the morning hours when both single- and cross-lake snow bands were occurring. One-hour snow accumulation totals included 2-3" at Wakefield, in the far northwestern part of the state; 2-3" between 1600-1700 UTC at Bellaire, in the northwestern portion of the lower part of the state; 2-3" at Montague, in the western portion of the state's lower part; and 2-3" between 1700-1800 UTC at Traverse City, in the northwestern portion of the lower part of Michigan.

Sample six-hour accumulations (from 1200-1800 UTC) from the eastern parts of upper Michigan were > 8" at Shingleton; > 5" at Seney, and 2" at Melstrand. Other nearby sites, including SSM, HTL, MKG, GRR, LAN, and FNT, reported trace amounts only, for the entire 6-hour period.

For more information on the nature of lake-effect snow, please refer to a report on a major 63" LES event.

The digital, McIDAS format data files are available by anonymous FTP to: "canopus.cira.colostate.edu". They are in directory 97016_LES. The 5-channel, full one-minute sector files are named with the conventional McIDAS "AREAnnnn" format, with nnnn=1000's indicating GOES Imager channel 1, nnnn=2000's for channel 2, etc. Channel 1 is visible, channel 2 is centered at 3.9 micrometers, channel 3 is at 6.7 micrometers (water vapor), channel 4 is the conventional IR window, and channel 5 is at 12.5 micrometers. Sets of the individual "AREAnnnn" files are also available in "zipped" format, collected in 143 self-extracting *.EXE files, with each of these containing all five channels for a 1-minute time period. These zipped, "LES_????.EXE" files, can be accessed directly by clicking here if your browser's "helper" option for .EXE files, under the Options/General - Preferences menu, is set to "SAVE".

The LES datasets cover a 23-hour timespan, from 0345 UTC on 16 Jan. through 0245 UTC on the 17th (with the VIS available from 1145-2255 UTC on the 16th). The SRSO period begins at 1104 UTC, with AREA?042 / LES_009.EXE, and ends at 1711 UTC, with AREA?153 / LES_102.EXE.