CIMSS Satellite Blog

An animation of 3-hourly water vapor channel image composites from AWIPS during the entire month of February 2007 (35 MB QuickTime animation; 1280×1024 screen resolution required) shows the diverse variety of storms that affected the Northern Hemisphere during that particular month. Significant weather events in the US included fatal tornadoes in central Florida (02 February) and New Orleans (13 February), heavy lake-effect snow in western New York (141 inches in 10 days at Redfield, 03-12 February), and winter storms affecting much of the eastern US (13-14 February) and the northcentral US and Great Lakes (24-26 February). February 2007 ended up being unusually cold and snowy across much of the Upper Midwest and Great Lakes regions — Grand Rapids, Michigan and Rochester, Minnesota had their snowiest February on record (33.6 inches and 19.6 inches, respectively), and La Crosse, Wisconsin experienced their greatest storm total snowfall on record (21.0 inches from 23-25 February).

An isolated thunderstorm developed over east-central Florida and moved over the Kennedy Space Center during the late afternoon on 26 February 2007, producing golf ball size hail (2.0 inches in diameter) and wind gusts as high as 72 mph (SPC storm reports). This hail produced damage to the external fuel tanks of the Space Shuttle Atlantis, which was on the launch pad undergoing preparations for a 15 March 2007 launch. This particular convective cell was relatively compact and formed rather quickly, and exhibited cloud top temperatures between -50 to -60º C (orange to red enhancement) on GOES-12 10.7µm InfraRed (IR) imagery (above; Java animation).

A comparison of 4-km resolution GOES-12 IR imagery with the corresponding 1-km resolution NOAA-15 AVHRR IR image (below) shows that more accurate (and significantly colder) cloud top temperatures can be detected using satellite instruments with better spatial resolution. Note the distinct “overshooting top” region with a minimum brightness temperature of -65º C (dark red enhancement) on the 21:50 UTC NOAA-15 image, versus cloud top temperature values that were only as cold as -54º C (orange enhancement) on the 21:45 UTC GOES-12 image (these two IR images were about 20-25 minutes prior to the time of the reported hail damage). The Advanced Baseline Imager (ABI) instrument on GOES-R (scheduled for launch in 2014) will have IR channels with a spatial resolution of 2 km, which should improve cloud top temperature detection capabilities over the current GOES imager IR channels.