South American MCC

[Willoughby Owen]

I was just looking over the latest 30-day global rainfall anomalies from NASA's TRMM satellite. To my bemusement there was a HUGE amount of rain that has fallen over far-southern Brazil, Uruguay and far-northeast Argentina... obviously an MCC since it's so far south and spring. I looked up the news on this event and it appears there were thousands of people evacuated due to flooding with numerous tornadoes embedded.

CIMSS in their blog had a good description of the event and an EXCELLENT satellite loop of the MCC!

http://cimss.ssec.wisc.edu/goes/blog/archives/3879

 

[Ryan Wichman]

Those are some very impressive cloud top temperatures, numerous times there were shots of near -90C!

Willoughby, do you have the link for rainfall totals down there? I'm sure they were just as impressive.

 

[Willoughby Owen]

I'm not sure what the rainfall totals were there but I'd assume plenty when seeing the anomaly chart.
http://trmm.gsfc.nasa.gov/trmm_rain/Events/latest_big_anomaly.gif

(So rare to see such a large blob outside of the tropics!)

 

[Josh Durkee]

I'm not sure what the rainfall totals were there but I'd assume plenty when seeing the anomaly chart.
http://trmm.gsfc.nasa.gov/trmm_rain/Events/latest_big_anomaly.gif

(So rare to see such a large blob outside of the tropics!)

-Actually it's not THAT rare, particularly during positive ENSO phases.

If you're interested in South American MCCs, here are some links to a couple recent papers of mine on the subject:

Subtropical South American MCC Climatology:
http://www.wku.edu/~joshua.durkee/publications/Durkee%20and%20Mote%20%5B2009%5D%20A%20climatology%20of%20subtropical%20South%20American%20mesoscale%20convective%20complexes.pdf

Subtropical South American MCC rainfall:
http://web2.wku.edu/~joshua.durkee/publications/Durkee%20et%20al.%20%5B2009%5D%20The%20contribution%20of%20mesoscale%20convective%20complexes%20to%20warm-season%20rainfall%20across%20subtropical%20South%20America.pdf

 

[Andrew Ryan]

On the link to the CIMSS page, they mentioned something about an "enhanced-v signature" that indicates severe weather. Is this at all related at all to a "v-notch" that can be found on supercells? I'm guessing not, but I thought I'd ask to see if anybody knew anything about that.

 

[Bob Hartig]

On the link to the CIMSS page, they mentioned something about an "enhanced-v signature" that indicates severe weather. Is this at all related at all to a "v-notch" that can be found on supercells? I'm guessing not, but I thought I'd ask to see if anybody knew anything about that.

I've wondered that too, when I've come across the term. Jeff Haby explains it simply. The difference appears to be which remote sensing device you're using to look at a storm: IR satellite or radar reflectivity. Satellite depicts an "enhanced V" of cold cloud tops blown downwind; radar shows the standard "V-notch" of dual precip bands streaming downwind from the storm. Both depict a similar phenomenon.

 

[Willoughby Owen]

If you're interested in South American MCCs, here are some links to a couple recent papers of mine on the subject:

Thanks for those links... interesting reading.