[emk8t]

When tracking severe storms, I know a "meso" has something to do with rotation... correct?

And also, when the radar does "detect" a "meso", what does "3 DC SHR" mean?

Just curious...

[rudi_in]

Thank you for posting your question to the Ask Me Help Desk.

Meso is really a prefix as opposed to a stand-alone word and it can have a couple different meanings.

It can refer to middle as in the word mesosphere which is the middle layer (3 of 5) of the atmosphere.

It can also refer to an intermediate size as in the word mesoscale which refers to a storm system which can be as much as 100 km in size.

As it pertains to rotation -- meso is used in the word mesocyclone. A mesocyclone is column of air that rotates within (middle) a severe thunderstorm.

As far as the 3 DC SHR goes, I am not entirely sure.

3 could mean a lot of things but I would have to see the entire report.
DC generally refers to the District of Columbia
SHR could refer to the magnitude of wind shear if talking about severe storms and mesocylclones

Maybe it is possible that if these were huddled together on a radar map and that 3 represented the amount of expected rain around DC and SHRewsbury, PA or perhaps SHRewsbury, MA?

[emk8t]

Thanks Rudi! Very helpful...

I was following some storms in IA moving into SW WI, and a few of them were teetering on severe-criteria... and I was watching the storms that NWS MKX was tracking, and the columns are: "Hail", "Meso", and "TVS" (I think TVS is "tornado Vortex Signature"? ) Hail was ranging from .5-1.75", and then this one storm, under "meso" went from "none" to "3 DC SHR" I have seen it say "yes" under "meso", but never "3 DC SHR". Sorry I didn't explain it more in detail before...clearly, I have no clue what I am talking about...BUT, that is why I asked:) I know just enough to confuse myself and everyone around me...

I'm been interested in Meteorlogy since I was a kid...(I wanted to be an astronaut, actually, and thought i better understand the "sky" first:) I was in 4th grade when the shuttle blew up, and I had to go home sick I was so upset....

Anyway, I started "officially" chasing storms about 2 years ago. I have a story posted on the NWS MKX website, from a Tornado I spotted in south-central WI in 2004. Since then, I've been hooked.

Can you offer any more insight with the additional info I provided?

Thanks!

[rudi_in]

This does help.

Yes, the TVS is the tornadic vortex signature.

3 DC SHR -- My understanding is that NEXRAD would show 3DCO but I suppose that could change. In which case it stands for...

3-D Correlated Shear

When this shows up, it means that a larger scale rotation is present -- one that is larger than what the TVS would indicate.

The original question, by the way, "what is a meso?"

This is the column that shows whether NEXRAD has located a mesocyclone.