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Locoholic wrote: ↑February 26th, 2020, 5:47 pm

IHateClouds wrote: ↑February 26th, 2020, 4:29 pm how do you guys differentiate between TVS and debris balls? like theyre both indicative of tornadoes and are always on a hook echo so i cant rlly tell them apart >w<

If it's pointing to the circular structure then I go with debris ball but if it shows like the whole thing then I say TVS

It's not like at regionals we put debris ball/TVS cuz we didn't know which one to put (cough cough Locoholic)

DerechosRYummy wrote: ↑February 26th, 2020, 6:18 pm
It's not like at regionals we put debris ball/TVS cuz we didn't know which one to put (cough cough Locoholic)

I mean the images need to be specific they can't expect us to differentiate if it doesn't have an arrow or smth pointing to what it's looking for

IHateClouds wrote: ↑February 26th, 2020, 4:29 pm how do you guys differentiate between TVS and debris balls? like theyre both indicative of tornadoes and are always on a hook echo so i cant rlly tell them apart >w<

TVS specifically refers to the signature in the velocity data (a velocity couplet) while a debris ball is seen on the reflectivity (and dual polarization radar products like correlation coefficient) as the radar directly "sees" the debris. TVS are much more common than debris balls, since it takes a strong tornado to loft enough debris to create a debris ball visible on the radar imagery.

weatherguy5 wrote: ↑February 26th, 2020, 6:35 pm
TVS specifically refers to the signature in the velocity data (a velocity couplet) while a debris ball is seen on the reflectivity (and dual polarization radar products like correlation coefficient) as the radar directly "sees" the debris. TVS are much more common than debris balls, since it takes a strong tornado to loft enough debris to create a debris ball visible on the radar imagery.

The problem is when a reflectivity image of a TVS is shown because the most common TVS images I see online also contain a debris ball. What should I do if I'm given an image of a TVS which shows a debris ball, and I'm asked what is being shown in the image?

Locoholic wrote: ↑February 26th, 2020, 6:46 pm

weatherguy5 wrote: ↑February 26th, 2020, 6:35 pm
TVS specifically refers to the signature in the velocity data (a velocity couplet) while a debris ball is seen on the reflectivity (and dual polarization radar products like correlation coefficient) as the radar directly "sees" the debris. TVS are much more common than debris balls, since it takes a strong tornado to loft enough debris to create a debris ball visible on the radar imagery.

The problem is when a reflectivity image of a TVS is shown because the most common TVS images I see online also contain a debris ball. What should I do if I'm given an image of a TVS which shows a debris ball, and I'm asked what is being shown in the image?

Ask the proctor. Like you said, the debris ball is the ball, and the TVS refers to the entire unit. Proctors do know what they are doing most of the time. They'll surely be nice enough to whip up the answer key and check what it is pointing to. I mean that's what we did in DP at regionals...Otherwise, there's a 50/50 chance of getting it right. Also, use context clues to determine which one it is. Use other questions to your advantage to get the question right.

Technically the term tornado vortex signature only applies to velocity imagery, since it refers explicitly to the couplet. From the AMS glossary a tornado vortex signature is:

(Abbreviated TVS.) The Doppler velocity signature of a tornado or of an incipient tornado-like circulation aloft.

From the AMS glossary again a debris ball (or tornado debris signature; they're the same thing) is defined as:

Often referred to as a TDS. A dual-polarization radar-based feature indicative of nonmeteorological tornadic debris present in the radar sample volume. It is typically associated with a significantly reduced copolar correlation coefficient, a low differential reflectivity, and sometimes an enhanced reflectivity factor, which are centered or nearly centered on a tornadic vortex signature.

So the TL;DR is that if its a velocity image its a Tornado Vortex Signature, if its anything else with an obvious ball in the imagery near where the tornado would be expected to be it's a debris ball or Tornado Debris signature.

However, I will readily concede that this is a distinction that a supervisor less experienced with Meteorology the event and the field of atmospheric science in general may not make very clear all the time. Which is why as a former competitor who discovered through this event that I wanted to do meteorology as a career I'm trying to get back to being more involved with volunteering/Event Supervisoring and why I lurk here.

twig wrote: ↑February 26th, 2020, 7:56 pm

Locoholic wrote: ↑February 26th, 2020, 6:46 pm

weatherguy5 wrote: ↑February 26th, 2020, 6:35 pm
TVS specifically refers to the signature in the velocity data (a velocity couplet) while a debris ball is seen on the reflectivity (and dual polarization radar products like correlation coefficient) as the radar directly "sees" the debris. TVS are much more common than debris balls, since it takes a strong tornado to loft enough debris to create a debris ball visible on the radar imagery.

The problem is when a reflectivity image of a TVS is shown because the most common TVS images I see online also contain a debris ball. What should I do if I'm given an image of a TVS which shows a debris ball, and I'm asked what is being shown in the image?

Ask the proctor. Like you said, the debris ball is the ball, and the TVS refers to the entire unit. Proctors do know what they are doing most of the time. They'll surely be nice enough to whip up the answer key and check what it is pointing to. I mean that's what we did in DP at regionals...Otherwise, there's a 50/50 chance of getting it right. Also, use context clues to determine which one it is. Use other questions to your advantage to get the question right.

I guess you could always write both, or write one and add a note explaining your opinions... (although it only works if you have a good proctor).
And yes, a debris ball implies an extremely powerful tornado.

Do y’all use Wikipedia or NOAA more for meteo?

Locoholic wrote: ↑March 7th, 2020, 5:37 am Do y’all use Wikipedia or NOAA more for meteo?

when i took the majority of my notes i used wikipedia but honestly i regret not using NWS jet stream and NSSL more >w< since meteo is so not in-depth i think that NOAA is honestly better

IHateClouds wrote: ↑March 7th, 2020, 5:43 am

Locoholic wrote: ↑March 7th, 2020, 5:37 am Do y’all use Wikipedia or NOAA more for meteo?

when i took the majority of my notes i used wikipedia but honestly i regret not using NWS jet stream and NSSL more >w< since meteo is so not in-depth i think that NOAA is honestly better

Interesting... I started with NOAA and I’m only now starting to use Wikipedia.