[轉錄]Re: Circulating storms

※ 本文轉錄自 [Meto_e] 看板

發信人: Scott <[e-mail]>, 看板: Meto_e
標  題: Re: Circulating storms
發信站: Space Science and Engineering Center (Mon Sep 27 11:28:18 2004)
轉信站: itcz!news2.wam.umd.edu!nntp.abs.net!news.maxwell.syr.edu!news.doit.wisc
Origin: castanea.ssec.wisc.edu

Gene Seibel wrote:
> "R. Martin" <[e-mail]> wrote in message news:<[e-mail]>...
>
>>Gene Seibel wrote:
>
>
>>Congratulations!  You have posted almost the only thing worth reading
>>on this NG is the past 24 hours.  It sounds kind of like you may be
>>describing what is called a mesoscale convective vortex (MCV), except
>>that those are usually not that close to stationary.  How big are they?
>>About the size of a Midwesetrn state, say Kansas?  How did you observe
>>them (radar reflectivity, visually, visual satellite images, ...)?  I
>>can't think of an underlying condition or conditions that have been
>>postulated to enhance both mesoscale mid-latitude vortices and
>>hurricane-scale tropical vortices (except maybe global warming ;-) ),
>>but that doesn't mean there isn't one.
>
>
> Saw them on Weather Underground radar. One I remember in Kansas was
> probably about 100 miles in diameter. Stayed pretty much stationary
> for the better part of a day. Same thing in Texas. The one in Texas
> dropped a foot of rain on a community and was big news that night. I
> was in San Antonio about 100 miles away with clear skies. Now that my
> curiosity is up, next time I will pay closer attention.


There are typically ~20 or so MCVs per warm season, according
to some papers by Davis and Trier.  If you use a RUC vortex
finding algorithm, you find maybe 40/year -- although some of
those are dry, and not the kind you'd see on a radar image or
satellite loop.  MCVs evolve out of MCSs that are in low-
shear environments.  I also cannot think of a reason why
their numbers would increase with time, other than interannual
oscillations associated with drought/wet years.  But that's
an oscillation not a trend.

<http://www.cira.colostate.edu/ramm/visit/mcv.htm>

There was an excellent example of an MCV over Oklahoma in
June this year (the 7th?) as well as over eastern NM/
western TX on July 20th.

The following 2 urls require java:

Some MCVs do nothing with the weather:
<http://www.ssec.wisc.edu/~scottl/satmet/IA_Aug2004/IAMCV.html>
Here's the case from NM/TX:
<http://www.ssec.wisc.edu/~scottl/satmet/NMMcv.html>

Scott