Author Topic: Micro-burst induced pressure rise  (Read 1445 times)

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Offline Old Tele man

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Micro-burst induced pressure rise
« on: August 13, 2017, 09:48:17 PM »
This morning's (13-Aug-17) monsoon 'thunder-n-lightning' downpour created an interesting plot (two attached below).

The combined sudden temperature drop and rainfall (0.41") was accompanied by a simultaneous almost sinusoidal bump up in barometric pressure that subsided exactly when the rain stopped.

Plot #1 Legend:
Brown = barometric pressure
Dark blue = RH
Light blue = rain
Red = temperature
Green = dewpoint temp
pink & horizontal blue = internal temp & rh
« Last Edit: August 14, 2017, 12:31:28 PM by Old Tele man »
SYS: Davis VP2 Vue/WL-IP & Envoy8X/WL-USB;
DBX2 & DBX1 Precision Digital Barographs
CWOP: DW6988 - 2 miles NNE of Cortaro, AZ
WU - KAZTUCSO202, Countryside

Offline CW2274

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Re: Micro-burst induced pressure rise
« Reply #1 on: August 13, 2017, 09:55:45 PM »
I was just talking to someone about this phenomena a couple of weeks ago. Mine this morning went from 30.02 to 30.12 in about two hours then back down. Cool stuff.

Offline DaleReid

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Re: Micro-burst induced pressure rise
« Reply #2 on: August 14, 2017, 08:31:30 AM »
Last year, after the  AZ an NM monsoons were over, some guy who spent two months on the road with talent and good equipment had a posting of some amazing downpours he was able to witness. 

Knowing how heavy water is, and seeing the fluid (both air and water) in motion with the 'splash' effect when the rain began to hit the ground and the outflow associated with it leaves little doubt that there is a effect is real.  I'm sure that there are multiple factors including the downflow with the rain dragging the air along, the change in temperature and so on.

You can't see it if you log pressures once an hour and our stations and software allow for these discoveries. 

The natural laboratory of isolated huge storms that we're seeing in these time lapse movies makes for an opportunity to see one of these develop, quickly deploy say five or six stations across the expected path, and then plot their readings to see when and where the pressures change, when rain starts, how much outflow compreession raises the pressures, and when they return to a steady state afterwards. 

Or we could just model this with our Crays in the basement.

But it is fun to fantasize about such a project. 

By the way, does anyone remember the name of the guy who posted those videos, on Vimeo, I think, of last year's monsoons?