typhoon_tip
(Meteorologist)
Sun Oct 23 2005 10:06 PM
Re: 00Z Soundings

Quote:

Key West Sounding
Helicity (spin) of 524m/s/s.

Tampa-Helicity of 256ms/s.

Miami-Helicity of 236m/s/s

Tip or Thunderbird12. Care to elaborate on the Helicity and the F scale if you have time.

BTW-Jeff Morrow is in Miami. He just said "I don't like the looks of that satellite right now!"~danielw




Hi Danny..
The kind of Storm Relative Helicity in question is a measure consisting of two parameters:
1) Stream line shear with height.
2) Directional shear with height.

1)...is the increase in wind velocity ascending through the layer in question.
2)...is the change in wind direction asceding in altitude.
The calculations are performed at 1km and 3km layers above ground level.

The units suggest this in being m/ss. The larger the SRH, the greater the chance for tornado development.
SRH Value Tornado Potential
150-299 weak
300-449 moderate
>450 strong

Simpler "Helicity" is just a measure of rotation in a storm's updraft... You can bet that a huge SRH value will be codependent.