Rain Potential Wednesday Night

The one thing that I love most about forecasting during the transition seasons (fall and spring) is the uncertainty they bring.  Our weather computer models seem to have some difficulties keying in on certain things often causing our forecast to change.  One thing that has been fairly consistent the past several days is the fact that our zonal (west to east) flow in the jetstream will soon be interrupted with a disturbance currently moving into the west coast.  This will cause an area of low pressure to quickly develop in the Plains Wednesday and move across the Great Lakes late Wednesday night/early Thursday morning.  Looking at the latest rainfall guidance suggests that we could squeeze out over an inch of rain with this system because not only will we be saturated at the surface but also throughout the atmosphere.  At this time, the severe parameters remain low and it would be more of a rain threat.  There are, however, a couple things that we'll be watching fairly closely with this system.  One thing a forecaster looks at is how the weather model initialized  (comparing it with what it says is going to happen to what is actually happening).  If it doesn't initialize well, then chances are the forecast it brings isn't going to be all that great.  And this morning we didn't do so good in that department.  Secondly, some of the latest runs are actually developing some of the heaviest rain to the north and south of the Stateline.  On the other side, we have been seeing this system for the past couple of days which does improve my confidence some with the rainfall.  Of course we'll continue to update you with this tonight and tomorrow morning.