Dynamic Cooling


Dynamic Cooling: Occurs when strengthening storms produce strong upward motion and heavy precipitation that cools the atmosphere. The cooling happens because of two things. First, rising air cools as it becomes surrounded by a cooler environment and is further removed from the source of heat (sun-warmed surface objects). Second, heavy frozen precipitation falling into a warm layer will result in latent heat being transferred from the air to the melting hydrometeors so that a phase change (solid to liquid) can occur. The net loss of heat energy in the air will cause it to cool.

HRRR Model Showing An Example Of Intense Dynamic Cooling On The NW Flank Of A Rapidly Developing Low In December 2016. Credit: Weatherbell
HRRR Model Showing An Example Of Intense Dynamic Cooling On The NW Flank Of A Rapidly Developing Low In December 2016. Credit: Weatherbell

Look for dynamic cooling when there is lots of upward motion in areas with heavy precip on the NW flank of a storm. Dynamic cooling can be strong enough to transition synoptic scale areas from liquid to frozen precipitation especially in the absence of strong warm thermal advection though if the dynamic cooling effect is greater than the thermal advection, a change from rain to snow can occur even in a warm air advection regime.

For a great example of dynamic cooling, check out my post on a rapidly intensifying storm system that occurred just after Christmas of 2016 and featured some intense dynamic cooling.

-Jack

 

One thought on “Dynamic Cooling”

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Reliably hype-free weather info for Western Maine and New Hampshire from amateur forecaster Jack Sillin

%d bloggers like this: