Posted: 5:00 am Thursday, July 13th, 2017
By Kirk Mellish
I’ve blogged and tweeted about the unusually high level of poor weather computer model performance the past few months in trying to predict hot dry weather of a lasting nature. They keep showing it coming, then back off those projections, and in the end it fails to show up.
Short-term we are having pretty typical July heat a couple degrees either side of 90 with a ridge aloft flexing in from the Bermuda High over the Atlantic with a 594 height:
Many of the models are showing the West ridge edging east for much of the remainder of July and on/off for August but more on. However, I will remain skeptical for at least a few more days and look for consistent signals.
There remains a great deal of uncertainty as to whether or not a mega dome ridge crosses east of the Mississippi river and if so how long it would last.
It does look like a heat wave is coming, but maybe not all that remarkable by Atlanta standards.
A “Dome” of high pressure “stacked up” in the atmosphere from bottom to top is what would be needed to shut off the thunderstorm faucet and bring a lasting heat wave. They are trying to move that West Coast-Rockies heat ridge/dome east into the Center and/or parts of the SE longer term.
The model bias has been to show too much ridging aloft east and not enough out west:
This shows consistency with model projections of the MJO (Madden Julian Oscillation), which you can google if interested.
A move to Phase 3 and maybe into 4 would support this, IF correct… indicating hotter with fewer storms and more sun July 18th and beyond.
The Euro Ensemble supports the ridging aloft building in the future:
Published research shows that largely speaking at least, in general, June weather patterns tend to continue in July, and July weather patterns tend to continue in August:
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