Chicago Flood and
Wisconsin Tornadoes"
17-19 July 1996
Overview of Satellite Imagery for 17-18 July 1996
GOES-8 8km Resolution, IR (Ch. 4)
17/0445Z - 17/0915Z
On the border of South Dakota, Nebraska, and Iowa, there is an MCS with cloud top temperatures of -68 deg C. Through the evening hours, this MCS appears to move very slowly eastward. The cloud tops begin to warm towards the end of this period. Another smaller MCS is located over north central South Dakota. It appears that the main polar jet is well north into Canada, but we'll take a look at the water vapor imagery and upper air data to confirm.
17/0945Z -17/1415Z
Although the cloud top temperatures are cooler than the previous period, the system does not appear to be dissipating. There appears to be a boundary that stretches from Iowa through Wisconsin, into Southwestern lower Michigan and out over lake Erie and into Pennsylvania. There appears to movement along this boundary from west to east. This evidence might alert one to the possibility "training" precipitation, and flash flooding.
17/1445Z - 17/1915Z
Still slow cloud movement showing in the enhanced IR imagery from west to east. Although difficult to discern, there may be some convective feedback from the cells that have moved out over lake Michigan and the developing cells to their southwest. Certainly day time heating is also playing a role here as well.
17/1945Z - 18/0015Z
Between 17/2215Z and 18/0015Z IR cloud top temperatures cool dramatically from -50 deg C to -70 deg C. Another MCS is forming
