As we look ahead to late-May and early June, “transition” is the word that comes to mind when describing the overall weather pattern.
We’re going to begin pulling out of this unseasonably chilly pattern late-week and we’ll replace it with a true summer-like regime. Note the differences at 500mb between now and this weekend:
Not only will the 80s return, but oppressive dew points can be expected as well by Friday (65-70 degrees). The sweat factor will be back in full effect!
With that said, there’s reason for concern that the flip to summer may not last.
Not only do we continue to see high-latitude blocking in place, but the MJO is showing signs of rotating into Phase 1 as we inch closer to early-June. That Phase 1 this time of year is a cool one for the eastern portion of the country. Note the tendency for eastern troughiness illustrated in Image 2 below.
Perhaps ensemble data is seeing this cooler transition in the pattern on today’s 12z run:
Bottom line, confidence is high on a summer-like flip as we welcome in the weekend, continuing into early parts of Week 2, but we don’t think it’s a “stick and hold” variety of warmth. There’s growing reason to believe a flip back to cooler conditions looms before we close out the month.