May has been a funky month with a progressive pattern aloft producing alternating periods of warm and cool weather. Overall, the chill is winning out with the month running below normal over a large swath of the central U.S. as of May 24th. Where are you summer?
The past 7 days have been especially cool from the Midwest into the Rockies.
Going forward the signals are strong that overall the pattern will continue cooler than normal. I showed the MJO (Madden Julian Oscillation) yesterday depicting an amplified flow going through phase 2, a known cool stage.
Following the dotted green line, you can see the MJO then cycles into phase 3. That too is very cool in both May and June.
This is the temperature departure forecast from the CFSv2 over that 10 day period. In line with what the MJO is depicting.
Finally, in early June the MJO has entered phase 4. If you're looking for a more summery brand of weather this is the phase for you. Check out the MJO temperature correlation for June.
Notice the difference in the temperature departure June 3rd-8th. Big improvement in this period.
Before we get there, I even have some short term good news. The sun is expected to make a return appearance Thursday which in itself is a positive. Just as nice, temperatures will warm in the strong May sun and many places will reach highs closer to normal in the 70s. My gift to you! Roll Weather...TS