Tuesday, July 19, 2011
July 19: Mesoscale Discussion #1662- North Illinois, East Iowa, Southwest Wisconsin
CAPE values are above 7000 right now, indicative of a very unstable air mass. Within this MCD is a channel of higher PWAT (Precipitable Water) than that of surrounding areas. For those unfamiliar with PWAT values, it's when a meteorologist on TV says there's X many inches of water in the air.
Anyways, PWAT values reach above 2 inches in this narrow channel, indicating some heavy rain is possible in these areas.
While current wind gusts and sustained winds are not impressive, a nearby stationary front up in the Wisconsin portion of this MCD (Mesoscale Discussion) will likely enact at least a portion of the damaging wind threat.
If a watch is issued, it looks like it will be a severe thunderstorm watch, and we will post that when it comes out.