Memorial Day is the unofficial kick off to summer for a lot of people. There is only about a week left of school, give or take, for most people, June is around the corner and even the most northerly spots in the United States would be rightfully upset if they saw snow. Still, late may and early June in the Upper Midwest is usually in the mid 70s for a high. Warm, for sure, but not sweltering.
This version of the earliest stretch of “summer” features a blocking pattern in the center of the country. A temporary pulse down in the overall flow into the ridge is allowing a bit of progression for the pattern. This means that on the western side of the ridge, there is room for the trough to lead to surface development.
And if you are a long time reader of the site, my book, or just a first timer generally knowledgeable of things meteorological, you will know southerly flow precedes low pressure, and that means a hot, humid warm up for the middle of the country. In fact, for the next week, most of the north central US will be double digits warmer than normal.
Low pressure at either coast, including the one driving warm air north, are keeping temperatures below normal in California and the mid-Atlantic, while the fact that it is just generally hot already this time of year along the Gulf Coast are dampening some of the numbers there.
The hot, soupy weather will lead to some afternoon convection for much of this warm region, while surface features bumped up into Canada will ensure a little bit of extra convection later in the week in the Northern Plains and western Great Lakes. The calendar will say June, but it will fell like July or August for a few days.