Summer temperatures will continue to average above normal due to earlier discussed dominant ridge of high pressure in the picture. While originally it was thought this would be the case, the ridge has proven exceptionally resilient and containing above normal temperatures as in previous hot summers. This, along with the predominant drier pattern over the region and points west and south (though intermittent convective rains have appeared); will only add to the heat. Originally; I went for temperatures up to two degrees above normal on the warm side and I'm adjusting that upward to; two to around four degrees above normal! If we attain the higher end of the range (around four degrees); that would place the region in the top five hottest summers.
The only saving grace for cooler temperatures over our region has been the periodic plunge of the cooler air from Canada brought on by the large semi-permanent upper low over eastern Canada. Note the pattern expected (below) has appeared with some regularity with the ridge certainly dominant.
Overall; the strong ridge is expected to continue to be a dominant player and will oscillate from the center part of the country to the east; bringing the periods of heat. Normal to below trends will be brought about by the dubious North Atlantic Oscillation /NAO/ cycling lower into neutral to possible negative phases (more below) which would aid in emphasizing the upper low and troughing over central and eastern Canada.
In my original Outlook, I basically looked for normal to below normal rainfall over much of the region, particularly the southern two thirds. The only change here is expanding the normal to below rainfall over the entire region. While some areas will see normal rainfall; I suspect more areas will see below normal and thus; have a dry summer overall because of the pattern established. My original rainfall Outlook is written below:
Bill Deedler - SEMI_WeatherHistorian