The clouds break in time for an open roof at the Super Bowl in Atlanta at the stadium.
Just a little quick blurb taking you on a journey through the early Sunday morning Feb 3 atmosphere because it’s a great example of how a small and unimpressive weather feature in the jet stream can create a good deal of weather as seen in the visible satellite image above.
Starting at the top way up high we look at the 250mb jet stream wind chart (34,000 feet or 6.4 miles high). Notice how the black lines “dip down” or take a dip jog or kink from Northern Indiana to the Gulf of Mexico and there is a jet stream streak or wind max of 100mph rotating through the base of this upper-level trough or short-wave:
Down one standard level to the 500mb jet stream (about 18,000 feet or 3.4 miles high) chart below. Notice a similar kink in the lines with a cold pool of air -20C shown by purple dotted line and 70% humidity in light green and a moisture feed from the Pacific Ocean to the Georgia coast 80% humidity.
We drop down one standard level to the 300mb jet stream wind level around 30,000 feet high, about 6 miles up on the chart below. Note how there is a southward jog or kink in the black pressure/height lines with a cyclonic turning of the wind flow. There is also jet streak wind max triplets shown in pink on the underbelly of this upper level low pressure area with divergence aloft (air spreading up and out and away causing lift and spin):
At the 500mb we also look at vorticity a clockwise or counter-clockwise spin in the troposphere (red shades positive vorticity, blue negative) same kink in the flow is seen. All these represent what we call a “short-wave” or short-wave trough of low pressure in the upper-level winds:
The positive vorticity advection (PVA) helps lift and spin air parcels lowering pressure and creating surface low pressure.
Vorticity is mathematically defined as the curl of the velocity field and is hence a measure of local rotation of the fluid. This definition makes it a vector quantity.
Lowering one standard level again to 700mb (about 10,000 feet or 2 miles) you see a similar pattern as the higher levels but weaker with 70-90+% humidity over parts of Georgia:
Leveling down one more standard to 850mb chart (about 5,000 feet or 1 miles up) note a very broad kink in the height field black lines and lots of moisture saturation over much of Georgia 80-100% humidity providing low clouds light fog and in some areas light rain or drizzle:
One more standard level down to the 925mb chart (about 2,500 feet or half a mile high) a closed low just off the Georgia coast and high humidity except in East Georgia where a weak wedge provided some drier air but you can see a kink in the temperature field 10C orange line over North Georgia:
Everything “aloft” leads to this one more standard level down to the surface weather chart early Sunday morning. You can see the upper level short-wave trough and vorticity created surface low pressure in the Gulf and off the Atlantic Coast, with the surface high pressure of the wedge to our Northeast helping to make the clouds and drizzle to start the day.
The clouds around sunrise Sunday:
Early Sunday AM radar and surface pressure:
The amounts were very light, in most cases just enough to wet the ground just a Trace to 0.03”:
So you see what happens way up impacts us here on Earth even when the weather “features” are weak and unimpressive looking at the weather charts. Also note how most people just “see” the weather out the window or as they are out in it. Meteorologists on the other hand analyze and attempt to predict it’s future condition by viewing the atmosphere the way it is... 3D, really multi-dimensional:
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