For those who are writing the obituary on 90 degree days this summer, keep in mind that the possible 90 degree season does not end until October. I don't count out rogue 90 degree days in mid to late August or even into September despite our cool ways of recent weeks. Pattern reversals do take hold and brief teases of late summer warmth can squeeze out late season 90 degree days.
In 2008, we picked up more 90 degree days in September (three) than we did in August (one)...none of the days as part of a heat streak and all standing on their own. We also did this in 1985 (three in September, two in August) and in 1970 (eight in September, five in August). Don't count out summer warmth yet.
An example of this is forthcoming for about a week from now. Modeling from the GFS and Euro have been relatively consistent in developing a ridge of high pressure in the eastern half of the country, with a trough of cool digging down along the Pacific Northwest coastline.
While there are some differences in specific evolution of the east ridge and west trough, both the GFS and Euro agree on it and agree it happens in about a week. This will result in a warmer regime developing in the eastern half of the country and will provide us chances at 90 degree highs late next week. This could happen as soon as next Thursday but we're looking at a three to four day window where a 90 degree high may occur. As modeled above, the warmest to average temperatures would occur across Minnesota and Ontario but warmth would spill into our region as well.
This warming trend isn't going to establish a run at record heat but it is going to be a reminder of summer. Remember that average highs, even next weekend, are still in the 84-85 degree range. It doesn't take a significant above average airmass to bump us towards or even above 90 for a day or two. Nothing you or I can't handle but a reminder that it's still summer.