From the original Outlook:
Overall, I look for summer temperatures to average around normal (-.5 to +1.0). Local analogue data for this summer generally shows normal to below normal averages. At the same time, projections for the upper wind pattern suggest ridging over the south-central part of the country will periodically expand into the Great Lakes bringing more heat into the region. The temperature outlook is a tough call and will mainly depend on the how strong the ridge becomes and its placement. At this time, it looks like the ridge will oscillate from just to our west (Midwest) to the eastern third of the country. This will bring periods of heat and cool downs (while working in conjunction with the upper low in Eastern Canada). Number of 90 degree days should be about average for the summer, 8-12.
I have decided to up my temperature departure for the summer to 1 1/2 to 3 degrees above normal. As far as 90 degree days, I originally went 8-12 days for the entire region. I will also boost that to 11-15 for the Detroit and Flint areas but remain with the original projection for the Saginaw Valley region
It will be interesting to see if the pattern of the analogues which showed the cooler (relative to normal) part of the summer coming in the second half. If that does occur, and usually the analogue projections are better at the overall pattern than their numerical departures, then August should contain closer to normal or possibly below temperatures. We shall see.
I see no need for precipitation changes as strong variability remains dominant. Some areas have had more than enough rain while others are dry and this is very similar to 2008.