We look to stay in a soupy “air you can wear” tropical air mass with hot afternoons and warm muggy nights: temperatures above normal day and night for at least the next 3 days. The big heat wave gripping most of the nation will shift out West next week.
High moisture air will be provided at times by the Bermuda High Pressure and at other times by Easterly Trade Waves off the Atlantic.
That combo plus an upper-level trough of low pressure over us will provide a potentially unstable air mass each day.
The sun will be out at times with hazy conditions and random scattered hit and miss showers and storms each day, a few heavy or strong.
An early morning or late night thundershower can’t be ruled out, but the main “window of opportunity or risk” will be 1pm to 10pm. (subject to adjustment each day-- hear that on WSB radio) but not raining the whole time so plenty of dry hours each day, no wash-out days foreseen as of now.
Remember the dead horse I’ve been beating for decades: thunderstorm forecasts UNLIKE others sometimes need to be updated every two hours or so (The complex reasons I’ve explained many times before- you miss a blog you miss a lot).
At least daytime highs should start to come down by next week with added clouds we break the back of the heat wave. We could even see high temperatures drop to the low to middle 80s and MAYBE drop morning lows to 70 or a bit below.
Early next week the Rossby long-wave jet stream pattern will be shifting the big heat dome ridge to the West allowing a long-wave trough into the Eastern U.S. helping to lower our temperatures but keeping the rain chance at least normal if not above-normal through early next week.
The GFSV3 Global Model indicates a cold front will bring drier air and low 80s starting next Wednesday. However, that would be a rare occurrence, fronts don’t often get that far South this time of year, so I’ll believe it when I see it and hold off putting it in my forecast for now.
SEE HOW WHAT I DESCRIBED ABOVE PLAYS OUT IN JET STREAM WEATHER MAPS (shaded areas disturbance energy swirls):
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GFS ENSEMBLE 500MB JET STREAM LEVEL HIGHLIGHTING AREAS ABOVE OR BELOW NORMAL:
5w
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SURFACE WEATHER MAP DAYS 3-7:
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SURFACE COLD FRONT PROJECTED NEXT WEDNESDAY:
WED
This time of year the normal or average (climate mean) chance of a thunderstorm is 40%.
In the weather pattern above the chance will be at least normal but occasionally 50-70% and on a lucky day 30%, but that can only be determined on a day to day basis and sometimes only 2-4 hours in advance.
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ESTIMATED AVERAGE RAINFALL ACCUMULATION BETWEEN NOW AND 8AM MONDAY:
5r
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