Mammatus and Virga - What's Up?

[Mike Johnston]

As sun was setting here in KC today, I noticed a lot of mammatus clouds and virga in the sky - no t-storm development. I've noticed this a couple of other times around here this March. Almost seems like there is an ingredient missing. In general, I would guess this represents kinematic/wind dynamics, but without the necessary thermodynamics? Any insight from those more knowledgable would be appreciated.

 

[Jeff Snyder]

Hmm.. I'm not entirely sure I understand your question. Mammatus clouds are oftentimes features of some thunderstorm anvils. So, if there were no thunderstorm anvils, I don't think what you were seeing were indeed mammatus. This may not be the case, as some websites (such as http://www.ucar.edu/educ_outreach/webweath.../cloudpic9.html ) note that mammatus clouds may form on the underside of non-anvil clouds, as well. The atmosphere is a fluid, so there are a myriad of different wave-type clouds, some of which certainly can look like true mammatus. The cirrostratus deck that covered much of the plains today was quite dense in spots, so I wouldn't be surprised to see virga-like features.

EDIT: In looking for some basic info on mammatus, I noticed that the text on http://www.crh.noaa.gov/lot/photos/Jul2004...atus/july13.htm is indentical to the text at the UCAR site linked above... Tsk Tsk for plagiarizing, WFO Chicago...

 

[Gaetan Cormier]

I'm really not sure, but I think reading somewhere that mammatus clouds do not exclusively form under Anvils.... :?:

Gotta find the website where I saw that....

 

[Jeff Miller]

Mammatus-like formations can form in clouds distinctly seperate from thunderstorms. There is, in fact a easy-to-understand explanation at the following site. Look toward the bottom of the page, very user-friendly explanation.

http://www.personal.psu.edu/users/m/l/mle1.../mle_essay3.htm

In summary, it is due to fallout, and is usually not as impressive as thunderstorm-variety mammatus. I have indeed also seen mammatus-type clouds apart from thunderstorms -- they were, indeed, very much akin to mammatus -- I would even dare call them such -- but not associated with anvils or thunderstorm turbulence of course - simply an atmospheric condition that mimics to a slight degree what can happen with anvils on a non-convective basis.

Hope this can help!

 

[mikegeukes]

I found some stuff on mammatus I posted last year.

Posted: Mon Jul 19, 2004 4:20 pm

Mammatus clouds gets its name, because of the puch like or baglike sacs that resemble cows udders. MOOOOOOO goes the cow. LOL Mammatus form in sinking air, when precip is carried aloft, is spread out at the top of the anvil, the precip particles composed of water and ice and since air is saturated and is heavier, it sinks. Sinking air warms, and the warming is used in evaporating the precip particles, if more energy is needed, the sinking air will be cooler than the surrounding air, and with relative humidities of 100 percent, you will see mammauts clouds. Mixing, evaporational cooling and virga seem to play a role in mammatus.

Mammatus often form on the underside of cumulonimbus clouds, especially underneath the anvil and seen more often with storms that are severe, but you can see mamatus with non-severe storms too. Mammatus also sometimes they can form underneath altocumulus, altostratus, cirrus, cirrocumulus and stratocumulus clouds. Mammatus usually are an indication the storms are weakening and threat for severe weather has passed, however they are exceptions to the rule, you can sometimes have mammatus on the backside of a thunderstorm, where you might have the storm dropping hail and/or storng winds. Mammatus are not a sign that a tornado is about to form. Mammatus clouds do not produce severe weather.

Source: Notes I have collected over the years.

Mike

 

[Travis Livengood]

Saw that as well, but I was out by Winchester Kansas. Once at around 4:45 and again at sunset.

Which by the way was a beautiful sunset.

 

[Darin Brunin]

Everyone in this area must have been looking at the beautiful sunset last night. I noted the mammatus as well although they were only part of the show. I wish I would have had my camera becuase it was a sight to see.

 

[Darin Brunin]

hmmm........I don't know why it posted this twice but oh well.

 

[David Schuttler]

Here is some non-severe utters from this morning in Tulsa
1400 utc
[Broken External Image]:http://stormdriven.web.aplus.net/sitebuildercontent/sitebuilderpictures/033105.jpg

[Broken External Image]:http://stormdriven.web.aplus.net/sitebuildercontent/sitebuilderpictures/img7493web.jpg

[Broken External Image]:http://stormdriven.web.aplus.net/sitebuildercontent/sitebuilderpictures/img7499web.jpg