Continuing updates, with Michigan Spring 2007.
Yes, the weather does in fact impact the local economy:

( from April 11, 2007)
Climate news focused on Michigan (links):
Recent News from Michigan State University RE Climate change
and the local agriculture / economy.
MSU summary of various agriculture / horticulture freeze threats
News from Traverse City area RE Spring freeze and Cherry crop
Commentary on Climate Change impacts on Great Lakes Region
USDA study of various Cherry crop perils (from 1996 and includes climate)
Agriculture / Climate news RE Spring 2007 growing season (links):
Crop damage news from California
Various links on crop freeze damage from the Carolinas