Rain bands

Len W

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Mar 14, 2019, 5:38:40 AM3/14/19

to Weather and Climate

Can these mesoscale rainbands be explained?

Some topographical influence I guess.

Len

Wembury, SW Devon

Smartie

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Mar 15, 2019, 5:45:51 AM3/15/19

to Weather and Climate

Thanks for pointing this out Len. As the bands were moving with the CF terrain is not a cause. Most likely- 'horizontal shear instability', see eg-

https://journals.ametsoc.org/doi/10.1175/MWR-D-16-0409.1

David

Len

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Mar 15, 2019, 8:41:43 AM3/15/19

to Weather and Climate

There seems a mixture of frontal cloud, clearly shown as higher cloud to the south, and cloud streets which are lower but of course not producing rain.

http://www.woksat.info/etcabc14/abc14-0947-b-uk.html

Does the image at 0947 show two fronts?

The northern most one being broken and associated with the rain bands.

This from Bernard Burton's site:

Len

Smartie

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Mar 15, 2019, 9:45:33 AM3/15/19

to Weather and Climate

Two cold fronts are marked on the 06Z FAX and a cold front and an occlusion on the 12Z. So my interpretation is that this is a kata-front with the rainbands located on the trailing surface (ana-) cold front. Ahead of this is the 'Shallow Moist Zone' (SMZ) which has shallow boundary layer convection - in the image BL rolls or cloud streets can be seen

David

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