Severe Thunderstorm Radar Signatures

[nickgrillo]

How does the NWS indicate a severe thunderstorm on radar? Is their any shots on the web of the "severe signatures" they look for to indicate a Severe storm?

 

[Jeff Snyder]

I think a lot of it depends on the environmental situation. VIL levels can be an indicator of hail size, though that greatly depends on the thermodynamic environment of the atmosphere. For example, VIL of 70 in summer in the tropics (thus high freezing level and wbz level) may not be an indicator of severe hail, while VILS of 55 in the plains in the early spring may indicate 'large' hail.

Bounded Weak Echo Region (BWER), Weak Echo Region (WER), rear inflow jet/notch, hook echo, etc., are all 'radar signatures' that can shed light on a storm's structure and strength. Even just looking at the radial velocities can tell ya something, though this again depends on the situation. If a storm is 80 miles from the radar, at night with a strong inversion in place, an elevated storm with radar-indicated winds of 65mph may not actually be severe, since the severe winds may not be reaching the surface courtesy of the strong inversion / stable near-surface layer...

Here is one quick link I found while googling... http://www.crh.noaa.gov/lmk/soo/docu/supercell.htm

 

[rdale]

There's no "severe weather signature" available on radar - you need to incorporate all aspects of meteorology (radar / profiler / model soundings) to help you figure out what the radar is telling you. What may be nothing more than a heavy shower on one day could be dropping a tornado on another.

 

[Jason Hetzel]

hey nick you might wanna also check this link out. this is how i taught myself to read radar signitures. a great place indeed.

http://www.skywarn.ampr.org/radartut.htm