According to the latest GFS models (above) from May 6 through May 8, periodic pockets of out-of-season cold will bring temperature departures crashing down to some 8C to 16C below the seasonal average.
But it’s on Sunday, May 9 that the real problems are forecast to begin.
A violent kink the jet stream looks set to deliver intense Arctic cold to the majority of the CONUS.
The image at top of this page shows the GFS temperature anomaly chart for Sunday, because that’s when a fierce band of polar cold is on course to streak west to east through the entire breadth of the U.S.
From Montana to Virginia, temperatures are scheduled to plunge as much as 20C below the seasonal norm.
Then, from May 10 to May 12 (image below), a rare mid-spring freeze sinks south to engulf Texas, Oklahoma, New Mexico, Colorado, Kansas, Nebraska and Wyoming.