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Poor Media Use of Weather Terminology
- Thread starter Jeff Duda
- Start date
JamesCaruso
Staff member
“The tornado did not leave behind any observable damage, so it's considered an EF-U, for unknown intensity.”
www.wflx.com
Never heard this term before. If there’s no damage isn’t it an EF-0?!?
NWS confirms EF-U tornado in Pahokee on Thursday afternoon
WPTV Meteorologist Sami Squires says the National Weather Service (NWS) confirmed a "short-lived" twister in Pahokee around 3:45 p.m.
Never heard this term before. If there’s no damage isn’t it an EF-0?!?
EF-U is a fairly recent thing, I think the idea was with a EF-0 there will be very minor damage (basically enough "damage" to show something moved through - the type of thing that scatters stuff around on the ground and maybe takes off some small twigs & leaves.. but no meaningful damage to anything), where EF-U is 'nothing found'.
EF-U is an underutilized option in the EF scale. It has been around since 2007, the implementation of the EF scale. Actually, tornadoes that don't produce any obvious damage (i.e., remain over open land without trees or structures, so...a lot of plains tornadoes) should be getting rated EFU. It's just that a lot of NWS personnel are probably more familiar with the older policies and so continued to rate such tornadoes as EF0, against the recommendation in the EF scale.
Randy Zipser
EF3
The local NWS office is expected to conduct a field damage survey following any event in which Doppler radar had indicated a continuous, well-defined TVS or "debris ball" signature, especially if any public/storm chaser reports were phoned in or submitted online during the event. Therefore, since a field survey is routinely conducted, the results will likely be reported as EF-0 if little or no detectable ground damage is visible. The NWS would probably not use the EF-U designation, as that might give the impression that no survey was done at all.
An example of where the EF-U designation might be appropriate is when a tornado occurs during the night over a sparcely-populated forest, where no one is around to observe (or hear) it. How does one rate accurately fallen or snapped-off trees, as they all look pretty-much alike? However, if some of the trees are debarked in some locations and not others, this might suggest the presence of suction vortices with higher windspeeds at the ground. In that scenario, a numerical EF rating might be justified.
An example of where the EF-U designation might be appropriate is when a tornado occurs during the night over a sparcely-populated forest, where no one is around to observe (or hear) it. How does one rate accurately fallen or snapped-off trees, as they all look pretty-much alike? However, if some of the trees are debarked in some locations and not others, this might suggest the presence of suction vortices with higher windspeeds at the ground. In that scenario, a numerical EF rating might be justified.
My local office (PHI) seems to have warmed up to using EFU . A few years back, they spent days trying to find damage in a mostly inaccessible wooded area ... finally resorting to a CAP flyover to find any rate-able damage (the last I heard, they still treated drone usage as a no-no). I forget what rating they ended up with ... but, when I mentioned the EFU possibility, they showed no interest.
Just a few months ago, a series of landspouts occurred ... one or two in CTP's area and one or two in PHL's CWA. One went through the Blue Marsh National Recreation Area and was caught on video from a boat on the lake. As I occasionally do, I assisted PHL with the survey (i.e., I was a team of one for the survey). It hit in a heavily wooded area adjacent to the lake ... this area was also inaccessible by land. PHL in this case did use EFU for this tornado. Clear evidence of a tornado (from the video) but no DIs found due to the location issues. By the way, that part of Berks County has no weather radar that gets good low altitude scans (well ... maybe the Climavision one in Lancaster County, but, that's not available to the general public), so, these were not well represented on radar.
Just a few months ago, a series of landspouts occurred ... one or two in CTP's area and one or two in PHL's CWA. One went through the Blue Marsh National Recreation Area and was caught on video from a boat on the lake. As I occasionally do, I assisted PHL with the survey (i.e., I was a team of one for the survey). It hit in a heavily wooded area adjacent to the lake ... this area was also inaccessible by land. PHL in this case did use EFU for this tornado. Clear evidence of a tornado (from the video) but no DIs found due to the location issues. By the way, that part of Berks County has no weather radar that gets good low altitude scans (well ... maybe the Climavision one in Lancaster County, but, that's not available to the general public), so, these were not well represented on radar.
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