KSHB: Weather: Action Weather Blog: Friday night thunderstorms

As I am writing this thunderstorms are raging our way. Below is Live Triple Action Doppler showing the torrents of rain in red. At least 3 inches of rain could fall in a few spots overnight causing flooding. The cold front is approaching, but like last weekend there are many other things going on. We have a tropical connection to the monsoon flow which usually is over the southwestern U.S., but it is being diverted over the plains. This is somewhat similar to what happened last weekend. The cold front will move slowly through and weaken Saturday. Rain could linger into Saturday morning. Then we must watch for a secondary surge of cooler air Sunday. As this approaches a few thunderstorms may occur, but nothing compared to what has been happening.

We are now up to 6 inches of rain this month at KCI. Wow! What a turn around after a dry July. June was wet as well, so add up the three months and this has actually been a wet summer. Amazing!

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This is more of a question than a comment.

One thing that has always puzzled me is how in the summer, we usually are the victims of extreme heat due to a "High Pressure" system.

High pressure implies that the air is very dense, and therefore heavier.

But, we also know from elementary physics applications (e.g. hot air balloons) that when air is heated it becomes thinner.

Then why aren't high pressure, and extrmeme heat in diametric opposition?? It appears to me that the warmer the air gets, the lighter it becomes hence less, not more air pressure.

Thank you.

RICHARD:
Hi, and thanks for writing! One thing to understand about high and low pressure is that they are RELATIVE to the air around them. You can have a cold high form up in Canada... and move south... dragging the cold air with it. Or a warm-core high might form over the Southwest and bring hot air to Kansas City.

One of my meteorology instructors has a great website, with a good description of the different pressure types:
http://www.theweatherprediction.com/basic/pressuretypes/

Thanks for posting!
Jamie