James Spann speaks to the media and the NWS concerning

[BadgerWXman]

the "more radars = better tornado detection" equation only works if you have a sufficient number of warm bodies looking things over.

I'd tend to disagree with this statement. Why would you need more bodies? All that would change is that you'd have better coverage and access to more readings from lower altitudes. What would be different? (Maybe I missed your point)

It will be really interesting to see how well dual pol does with improving FAR. I've always been in the "more 88D coverage before dual pol" camp, but I'm still looking forward to the improvements either way.

[isohume]

I'd tend to disagree with this statement. Why would you need more bodies? All that would change is that you'd have better coverage and access to more readings from lower altitudes. What would be different? (Maybe I missed your point)

It will be really interesting to see how well dual pol does with improving FAR. I've always been in the "more 88D coverage before dual pol" camp, but I'm still looking forward to the improvements either way.

Dual Pol will do more to increase hail detection than tornadoes. By design Dual Pol helps to differentiate btw p/types which will help in severe and winter wx products. There is a "feature" on Dual Pol differential reflectivity that allows you to interpret the derbies balls better...but this is more of a gee-whiz since we can already account for debris balls.

[tornadotony]

Dual Pol will do more to increase hail detection than tornadoes. By design Dual Pol helps to differentiate btw p/types which will help in severe and winter wx products. There is a "feature" on Dual Pol differential reflectivity that allows you to interpret the derbies balls better...but this is more of a gee-whiz since we can already account for debris balls.

I did my research project for my radar course last fall on dual pol and its applications in tornado detection. From what I gathered, zdr and rho-hv will aid in the detection of debris from smaller tornadoes that are typically harder to distinguish on conventional reflectivity. This was shown pretty well on our Valpo dual-pol radar on 10/26/10, when we had an EF1 about 8 miles from campus. The dual-pol spectra picked up a debris sig, while conventional reflectivity didn't.

[gymengineer]

People will always die in bad weather... the death toll up there was not that high considering.

Using all resources for a warning is probably the best policy for now, perhaps refining some like the sirens. But still, you run into issues.. power outages, etc. Mike Smith and I'm sure others have noted that many of the highest fatality areas in Alabama had been without power most of the day before the tornadic storms got there.

On a side note: I don't know anyone who has their cell phone turned off during the day.

Absolutely-- there was something very wrong with that day. Take away the monster Hackleburg/Phil Campbell EF5 (anomaly in strength) and take away the Tuscaloosa/Pleasant Grove (anomaly in hitting such a densely populated area) and you *still* have multiple other EF4's killing over 20 people each.

[isohume]

I did my research project for my radar course last fall on dual pol and its applications in tornado detection. From what I gathered, zdr and rho-hv will aid in the detection of debris from smaller tornadoes that are typically harder to distinguish on conventional reflectivity. This was shown pretty well on our Valpo dual-pol radar on 10/26/10, when we had an EF1 about 8 miles from campus. The dual-pol spectra picked up a debris sig, while conventional reflectivity didn't.

You can still see minor debris balls on regular reflectivity depending on how close the storm is to the radar...it's just not as evident. This wont be a huge SA increase since the large tor debris balls are easily seen on any radar. Dual pol will also be limited by range to radar, so no increase of value will be had there either.

[The Great Zo]

I'd tend to disagree with this statement. Why would you need more bodies? All that would change is that you'd have better coverage and access to more readings from lower altitudes. What would be different? (Maybe I missed your point)

It's a matter of time management and workload. The more radars you have to analyze, the longer it takes. There isn't any way to just display the "lowest elevation of any radar" composite on AWIPS, and even if you could, it would be a disaster of differing resolutions/time-steps/doppler directions. You have to manually interrogate each radar, switch a D2D pane to the next one, and so on. That's complicated enough if you're trying to look at a storm on an 88D and also on one or two TDWRs, and I can't imagine how time-consuming it would be to tack on a handful of CASA radars too (not to mention the screen real-estate it'd take up).

In the days of just using one radar for everything, it was easier -- and we were less accurate. So it goes.

It will be really interesting to see how well dual pol does with improving FAR. I've always been in the "more 88D coverage before dual pol" camp, but I'm still looking forward to the improvements either way.

As others mentioned, I'd tend to agree that dual pol will do little if anything to enhance tornado warnings. I would expect significant improvements in hail detection and rainfall estimation to be the primary severe weather benefits.

[Hoosier]

Here is what I call a blanket tornado warning - I believe we had to blow the sirens at least three times for this particular event. This was the high risk day.

http://mesonet.agron...-KPAH-TO-W-0160

Your blanket warning seems rather dull or at least not as well structured (PAH doesn't mention the damaging wind threat until the very last sentence). Here's how it typically looks here (this one is from 4/19):

* AT 930 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A

SEVERE SQUALL LINE CAPABLE OF PRODUCING BRIEF RAIN-WRAPPED

TORNADOES IN ADDITION TO WIDESPREAD STRAIGHT LINE WIND DAMAGE.

THESE DANGEROUS STORMS WERE LOCATED ALONG A LINE EXTENDING FROM...

I'm not sure if it depends on who is on duty but there must be some level of discernment because other squall lines only trigger a SVR with the last paragraph having something like "INTENSE SQUALL LINES OCCASIONALLY PRODUCE BRIEF TORNADOES. ALTHOUGH NOT IMMEDIATELY LIKELY, IF A TORNADO IS SPOTTED..."

[isohume]

It's a matter of time management and workload. The more radars you have to analyze, the longer it takes. There isn't any way to just display the "lowest elevation of any radar" composite on AWIPS, and even if you could, it would be a disaster of differing resolutions/time-steps/doppler directions. You have to manually interrogate each radar, switch a D2D pane to the next one, and so on. That's complicated enough if you're trying to look at a storm on an 88D and also on one or two TDWRs, and I can't imagine how time-consuming it would be to tack on a handful of CASA radars too (not to mention the screen real-estate it'd take up).

In the days of just using one radar for everything, it was easier -- and we were less accurate. So it goes.

As others mentioned, I'd tend to agree that dual pol will do little if anything to enhance tornado warnings. I would expect significant improvements in hail detection and rainfall estimation to be the primary severe weather benefits.

I forgot about that. Yes, Dual Pol will probably be most effective and add the most value to precipitation processing. The algorithms that make up FFMP and such will have better data to begin with. Data that is not contaminated with hail or over-processed virga. Flash flood warning numbers should increase.

[The Dude]

There's some really great discussion in this thread.

One way for what?

I doubt most folks take a temp forecast of 88 to mean the temp will always hit 88. From their past experience of seeing a range of outcomes...they probably take a fcst of 88 to mean upper 80s or near 90.

By using a specific number, it attempts to relay an inaccurate level of certainty, which can cause people to underestimate the probabilistic nature of the forecast.

Agree

We have one local station that will not use POP's. I don't blame them

They will use terminology such as scattered - numerous - widespread

I hate POP's - but that is just me.

Smart approach.

[radarman]

It's a matter of time management and workload. The more radars you have to analyze, the longer it takes. There isn't any way to just display the "lowest elevation of any radar" composite on AWIPS, and even if you could, it would be a disaster of differing resolutions/time-steps/doppler directions. You have to manually interrogate each radar, switch a D2D pane to the next one, and so on. That's complicated enough if you're trying to look at a storm on an 88D and also on one or two TDWRs, and I can't imagine how time-consuming it would be to tack on a handful of CASA radars too (not to mention the screen real-estate it'd take up).

In the days of just using one radar for everything, it was easier -- and we were less accurate. So it goes.

As others mentioned, I'd tend to agree that dual pol will do little if anything to enhance tornado warnings. I would expect significant improvements in hail detection and rainfall estimation to be the primary severe weather benefits.

We collaborated with folks at Silver Springs and created a modified version of AWIPS that ingests/displays CASA data and is being used operationally in the Norman FO. Initial feedback does indicate a little bit what you're mentioning... that navigating between everything can be a bit cumbersome. But the instructions we're giving are basically, "drill down".

Start with Nexrad data. If something catches your eye, or you suspect development, go to network based CASA products. This is a major emphasis. You start getting away from the "per radar" paradigm and think of it more on the system level. Merging the products together works fairly well when the focus is coordinated low level scans, and we task the system to keep revisit time latencies in mind when scanning certain phenomena. (like looking at a potential circulation signature with the intention of creating good multi-doppler analysis). You also focus on wind vectors instead of radial velocities. Should you still want more traditional information, you can then go further and look at the individual radar products.

It's really the only way to keep up...

It will be interesting to see the differences in AWIPS 2 which is scheduled to be rolled out here in the next 12 mos.

[Chicago Storm]

http://meteorologica...logists-do.html

Snip from his blog posting

Yet, for reasons meteorologists do not understand, the funnel cloud never made it to the ground. That is good -- no tornado damage and no one injured. But, it left people grumping about having to interrupt their activities because of the warning.

But, look the radar image again and you see a dot and the word, "Wichita." That is downtown Wichita where the annual Wichita River Festival was in progress. Because Sedgwick County sounds the sirens countywide, the River Festival and its patrons were subjected to an unnecessary false alarm due to the structure of the county's siren network. It is "all or nothing." That put River Festival officials in a no-win situation. They made the right decision (in my opinion) to shelter.

Fortunately, Sedgwick Co. is in the process of changing the configuration of its siren network so that by tornado season 2012 the sirens will only go off in the path of the storm.

LCL's were at or over 1500m, which is one possible reason.

[isohume]

By using a specific number, it attempts to relay an inaccurate level of certainty, which can cause people to underestimate the probabilistic nature of the forecast.

Well if we gave a 5 degree range...we'd be accused of being too vague or hedging. Can't win, and I doubt folks are disserviced either way. We only give the number value through the short range anyway...after that we use general terms.

[radarman]

It will be interesting to see the differences in AWIPS 2 which is scheduled to be rolled out here in the next 12 mos.

One other thing to mention is regardless of the future of CASA or similar systems (which is highly unclear), the ability to navigate through heterogeneous sensor data quickly will be a big challenge and highly important going forward. The National Research Council is making a big push on Network-of-Networks, basically exactly this issue, but it can be like herding cats at times.

Hopefully AWIPS2 was created with this sort of thing in mind, and we have spoken of the idea of "cloud sensing"... Not sensing actual clouds, but quickly and automatically bringing in data from the appropriate sensor-nets based on SA.

A brief example might be, if a dryline is forecast in the models, you'd get a "recommended" subset of data delivered: satellite, dewpoint, refractivity, and radar.

If it's a marginal snow storm, maybe it's Temp soundings, SREFs, barometers, etc.

(edit: I see Google browsing--- they'd be good at this probably)

[Cajun Thunder]

Agree

We have one local station that will not use POP's. I don't blame them

They will use terminology such as scattered - numerous - widespread

I hate POP's - but that is just me.

I understand the use of areal coverages by media, but don't automatically assume that the public has a clear understanding of them. The reason the term "widely scattered" is no longer used by the NWS is because it was found that people had the mistaken impression that "widely scattered" (20%) thunderstorms meant there would be MORE thunderstorms than "scattered" (30-50%) thunderstorms. I'd also question whether John Q. Public really knows the difference between "numerous" and "widespread".

We find too often that the terminology we use (especially in AFDs) is "preaching to the choir". While most of the wording we use is easily understood by the denizens of this board, I question how effective it is for the general public.

I've been to several NWS workshops that have spent significant time in regards to societal impacts of our products. It is a subject that the field is becoming more cognizant of. As an example, during the Deepwater Horizon incident last year, there were at least several thousand workers in the area that were not acclimated to summer weather along the Gulf Coast (above and beyond those that might normally be in the area). In addition, they were wearing protective equipment, compounding the problem. Understanding that, we opted to be a little more liberal in issuing heat-related products during the incident.

I am glad to see that the societal aspects are being looked at to enable us to become more effective in getting the public to respond in a positive way to the information that we provide them.

[Cajun Thunder]

I'd tend to disagree with this statement. Why would you need more bodies? All that would change is that you'd have better coverage and access to more readings from lower altitudes. What would be different? (Maybe I missed your point)

It will be really interesting to see how well dual pol does with improving FAR. I've always been in the "more 88D coverage before dual pol" camp, but I'm still looking forward to the improvements either way.

Why would we need more bodies?? Are you serious?? Somebody needs to be looking at the information from all these extra radars.

Do you want to wait for the software to signal a TVS before issuing a tornado warning?? If you do, the POD will drop as will the lead time (usually significantly). Sometimes you won't even get a TVS. You going to issue a tornado warning just based on the radar signalling a mesocyclone?? The FAR will go through the roof.

I will tell you right now that in a severe weather event of any magnitude, one person looking at radar information in a CWA is NOT NEARLY enough. And you want to double or triple the amount of radars, with the same amount of manpower?? It quickly becomes data overload.

[DaculaWeather]

I don't know... my weather radio barely picks up the radio signal, no way it's going to pick up a GPS satellite too. I currently use my own EMWIN receiver with some client software on my laptop, I also re-broadcast the alerts to people that have subscribed to my free service. I also resend to people signed up through email, Twitter and Facebook automatically.

[Memphis Weather]

Your blanket warning seems rather dull or at least not as well structured (PAH doesn't mention the damaging wind threat until the very last sentence). Here's how it typically looks here (this one is from 4/19):

* AT 930 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A

SEVERE SQUALL LINE CAPABLE OF PRODUCING BRIEF RAIN-WRAPPED

TORNADOES IN ADDITION TO WIDESPREAD STRAIGHT LINE WIND DAMAGE.

THESE DANGEROUS STORMS WERE LOCATED ALONG A LINE EXTENDING FROM...

I'm not sure if it depends on who is on duty but there must be some level of discernment because other squall lines only trigger a SVR with the last paragraph having something like "INTENSE SQUALL LINES OCCASIONALLY PRODUCE BRIEF TORNADOES. ALTHOUGH NOT IMMEDIATELY LIKELY, IF A TORNADO IS SPOTTED..."

That's how the ones issued by MEG have usually looked. Personally...as I stated yesterday...I prefer the blanket SVR with the said Call-to-Action and then upgrade for specific circulations if/where they develop...though as has been excellently discussed...it remains a tough situation to get a handle on.

I guess this is my frustration. You've posted where IND (and others with other WFOs) have found a TON of EF0s and EF1s when going out and surveying these QLCS tracks post-event. Though I would still prefer these being handled without full blanket warnings...at least it makes them look more legitimate. The problem here in the MEG area...and what I'm about to say is NOT a knock to them...is that MEG does not go out and survey after these events...UNLESS there is a confirmed damage area that is believed suspect by officials on-scene. Most other WFOs...including LZK and PAH that neighbor MEG...will go along suspected tornado tracks (often with no damage reports whatsoever having come in) and that's where they find a lot of their weaker tornadoes...especially in these QLCS situations.

I actually don't mind this method by MEG...because it is very unlikely you're going to miss anything except the brief EF0/EF1 spin-ups that happen in the middle of nowhere...and force the survey crew to be on "broken twig patrol" all day. But...the problem then becomes...if these areas are not surveyed for spin-ups after the fact...then why are they issuing these type of warnings to begin with. Its almost like voluntarily raising the FAR.

Reading this thread...which has been a fantastic read btw...its clear I'm in the minority in how I would like to see these events being handled. But...I guess my personal experience is maybe what's making me have that perspective (though I tend to be pretty conservative in both severe weather forecasting and radar analysis to begin with). My fear is that we've seen 18 tornado warnings in the biggest population center in this region this year...with not one tornado confirmed. That's 18 times the sirens have sounded county-wide...and most of these were in a 3-week period in April. I'm speculating of course...and have no way to know what I say will bear out...but I do fear that during the next event...if all of a sudden we have a serious situation in the Metro area with a damaging tornado...that people who may have taken it seriously before this year may not do so now because they thought it was "no different than the last 20 times". And again keep in mind we also have the "luxury" of a TV met here in Memphis that will outright dismiss TOR warnings almost upon issuance...even legitimate warnings at times. That makes it even more frustrating and troubling in a potential future event.

[BadgerWXman]

Why would we need more bodies?? Are you serious?? Somebody needs to be looking at the information from all these extra radars.

Do you want to wait for the software to signal a TVS before issuing a tornado warning?? If you do, the POD will drop as will the lead time (usually significantly). Sometimes you won't even get a TVS. You going to issue a tornado warning just based on the radar signalling a mesocyclone?? The FAR will go through the roof.

I will tell you right now that in a severe weather event of any magnitude, one person looking at radar information in a CWA is NOT NEARLY enough. And you want to double or triple the amount of radars, with the same amount of manpower?? It quickly becomes data overload.

I guess it must be a pain to monitor things with AWIPS... I can understand that one person on radar during a severe weather event as it is could be tough. I guess what I'm failing to understand is what the difference would be if there were more 88Ds to work with. I would think that the workload depends on the size of the CWA and how much storm activity is going on, not how many radar sites are available to monitor said storms. It's not like you're increasing the coverage area.. just the quality of data available.

I must be too unfamiliar with AWIPS to fully understand the idea that more radar sites = more workload

[gymengineer]

Reading this thread...which has been a fantastic read btw...its clear I'm in the minority in how I would like to see these events being handled. But...I guess my personal experience is maybe what's making me have that perspective (though I tend to be pretty conservative in both severe weather forecasting and radar analysis to begin with). My fear is that we've seen 18 tornado warnings in the biggest population center in this region this year...with not one tornado confirmed. That's 18 times the sirens have sounded county-wide...and most of these were in a 3-week period in April. I'm speculating of course...and have no way to know what I say will bear out...but I do fear that during the next event...if all of a sudden we have a serious situation in the Metro area with a damaging tornado...that people who may have taken it seriously before this year may not do so now because they thought it was "no different than the last 20 times". And again keep in mind we also have the "luxury" of a TV met here in Memphis that will outright dismiss TOR warnings almost upon issuance...even legitimate warnings at times. That makes it even more frustrating and troubling in a potential future event.

I don't think it's clear you're in the minority. The NWS mets are understandably going to defend their methodology. Those who aren't mets are understandably going to approach this from a "beyond just the science" point of view. We know that after major events, the service assessments oftentimes do address the issues that people raise about phrasing of warnings and do issue recommendations-- some of which are put into place.

For example, after Katrina, there were several recommendations made that specifically addressed the wording of advisories and warnings:

(About the "doomsday" wording) FINDING 1: This statement was highly effective in reinforcing the message from emergency management for residents to rush preparations to completion and heed evacuation orders. Templates for these statements are available in an older software program (WWA) at NWS field offices but have not been transitioned to the current operational software program (GHG).

RECOMMENDATION 1: NWS Headquarters should ensure templates for these statements that emphasize potential impacts following major hurricane landfalls are available in operational software at appropriate NWS field offices. The templates should be pre-coordinated with local emergency managers.

FINDING 2: Feedback from customers and partners indicates that while the Extreme Tropical Cyclone Destructive Wind Warnings issued during Katrina were useful, the issuance under the TOR code and inconsistent product format/language caused confusion.

RECOMMENDATION 2A: The NWS should implement a separate code for Extreme Tropical Cyclone Destructive Wind Warnings and a standardized product template.

RECOMMENDATION 2B: The NWS should develop and distribute a one page outreach fact sheet describing Extreme Tropical Cyclone Destructive Wind Warnings to WFOs in tropical cyclone prone areas. WFOs should use this information to educate partners and users.

I said in another thread that I suspect that "tornado emergencies" might be recommended to be more standardized. I'm not saying that one would have definitely helped in Joplin, but just that it's a tool that some forecast offices use currently while others do not. And for the offices that do, the criteria are not all the same.

As for the issue of over-warning, I think about the public's behavior during "flash flood warnings" in the LWX forecast area. The potential is certainly there for a loss of life during a truly bad flash flooding situation since almost everyone goes about their normal business during our FFWarnings. They are issued at least several times a year for the immediate DC region, and most people under them don't see any flooding. I agree with everyone here that it is a tought balance, but I like that the conversation is happening... and I hope that it carries to other phenomena such as flood-type warnings as well.

[Cajun Thunder]

I guess it must be a pain to monitor things with AWIPS... I can understand that one person on radar during a severe weather event as it is could be tough. I guess what I'm failing to understand is what the difference would be if there were more 88Ds to work with. I would think that the workload depends on the size of the CWA and how much storm activity is going on, not how many radar sites are available to monitor said storms. It's not like you're increasing the coverage area.. just the quality of data available.

I must be too unfamiliar with AWIPS to fully understand the idea that more radar sites = more workload

It's not the quality of the data that is the issue. It's the amount of data you must filter through. Say you have to look at 4 or 5 different radars instead of 1 or 2. And interrogating storms on each of those radars. Say with 1 radar...you might look at 5 or 6 different elevation slices for a storm or cluster of storms. Now on a moderately busy day, you expand that to possibly 4 or 5 radars...that's 20 or 30 different cuts you are trying to look at in the same amount of time. Even if you are only spending 10 or 15 seconds looking at a particular cut to determine whether there is useful information in that scan, you are still burning time. Time you don't have.

Storm activity is the big factor in determining how busy you are. Having to look only at 1 or 2 storms isn't that difficult in the 4 or 5 minutes during a volume scan. If you have 10 or 15 storms to look at...that's a bunch of data to mentally process. And...that's pretty much par for the course in the south for most of the year. If you wait for mechanized alerts (TVS, Meso, VIL) to trigger your decision making, you are giving up 4 or 5 minutes of lead time you might have otherwise.

Have you spent time in the hotseat...where you are the one making the warning decision?Especially for hours on end...not just an hour or two.

[mcalvert]

Frankly, I wish the media and public would get over is the obsession that 80 MPH tornado winds are somehow more special than 80 MPH straight line winds. Why does it really matter what knocked your poorly-constructed pole barn down?

There is a difference in the damage caused by tornadic winds and straight-line winds, but the vertical component has little to do with it. Instead, it's the change in wind direction that causes additional damage.

If you have a tree that is hit by a southerly wind that is above the yield point but below the tensile failure or buckling point, the northern side of the tree will undergo compression and the southern side of the tree will undergo tension. The cellulose fibers in wood typically handle tension much better than compression and on the lee side of a tree that is bending significantly under wind load, you will find that compression fractures occur. This is where the cells actually rupture, but the compression isn't enough to actually buckle the tree. However, the cellular damage decreases the tensile strength of the wood so that when the winds change direction, the tree will more readily snap along the fractures. A straight line wind of the same magnitude would leave the tree bent from the compression fractures, but still standing.

This same effect is seen in hurricanes due to the change of direction of eyewall winds.

[New England Storm]

When Spann talks - people listen

Quite an amazing meteorologists

Article

http://www.alabamawx.com/?p=48699

Clips from the article

I ask the NWS to consider stopping the use of tornado warnings when trying to catch small spin-ups within a squall line (or QLCS). These tornadoes rarely last more than a few minutes, and are next to impossible to detect in advance. And, in most cases, the greatest damage from a QLCS is from widespread damaging straight line winds, not tornadoes.

and

*NOAA Weather Radio must be upgraded to the polygon warning system soon, or it will become obsolete.

Sure, it is the best thing we have now, and I still promote it heavily. But, why hasn’t NOAA upgraded their system so the receiver manufacturers can produce models with GPS included so they sound only when the receiver is a in a warning polygon? If something doesn’t change soon, the private sector will be the ones that push the warning process into the new technological era.

and

*Social media is not a time waster or a novelty, it is a lifeline during severe weather, and must be used by TV meteorologists.

Lives were saved April 27 by pushing tornado information to the masses through Facebook and Twitter. Seems like many old school news directors think this stuff is for high schoolers. How wrong is that; these social media services are mainstream and reaches across all demographics.

And, you just can’t throw up a Twitter or Facebook account and expect to be successful. It takes years of conversation and interaction with followers to grow your numbers and reach critical mass.

Broadcasting is now a conversation. The people that follow you on Facebook and Twitter aren’t idiots… they are our friends that can offer a treasure trove of information during active weather and any kind of breaking news event. They follow you, you follow them. Most media people just don’t get it.

More in his article above...

I like maybe not useing the tornado warning for the small spin ups, In the uk were almost all tornado events are small spins ups they use wording in the weather warning ( a tornado can not be ruled out with this system) they could put a word like that in a svr thunderstorm warning or maybe have a new type of warning.

[New England Storm]

Many people don't have internet access at work, and have cell phones turned off.

I know that the events of last week were highly anomalous, but nobody in MA has a NOAA wx radio, and they certainly aren't going to not go to work based on thunderstorm potential, so how exactly should they be warned? Sirens really seem like the only way, unless we want to govt. fund a few million radios.

[/quo

During that night I was in Brockton at the honors dinner for Massasoit students. When I got to the school the dean wanted to lock us in the fine arts building "because we were under a tornado warning until 8 pm" we were not under a tornado warning at any time, and even has all of the people were watching the tvs in the building showing tornado videos many people said " oh thats no big deal, it looks like it was only a weak storm, it could never be a big storm, it will never make it out of Springfield, why are they talking about this, it is a waste of time ect" Some folks Have no clue what is going on even has we had hail falling around us and winds near 50!

[huronicane]

During that night I was in Brockton at the honors dinner for Massasoit students. When I got to the school the dean wanted to lock us in the fine arts building "because we were under a tornado warning until 8 pm" we were not under a tornado warning at any time, and even has all of the people were watching the tvs in the building showing tornado videos many people said " oh thats no big deal, it looks like it was only a weak storm, it could never be a big storm, it will never make it out of Springfield, why are they talking about this, it is a waste of time ect" Some folks Have no clue what is going on even has we had hail falling around us and winds near 50!

[JoMo]

Joplinmet from the forum uses Facebook to communicate the warnings to people. I don't know how he manages to keep his cool as people are...... frustrating......to warn. Lots of people ask what to expect at their locations, some have no sense of the area, directions, etc...

[The Great Zo]

It will be interesting to read the assessments, once finished, concerning this years deadly tornado outbreaks/events. I would like to hear feedback on the use of tower cams in getting peoples attention and the use of Twitter and/or Facebook in spreading the word about the threats.

The monitoring of social media and TV feeds during severe events is growing in the NWS, but I don't think many forecasters consider it an essential source of information as of yet. Part of that is the rather usual "status quo" pushback from older forecasters, who are most comfortable sticking with tried-and-true methods (spotter calls, amateur radio, etc.) Part of it is also a consideration of workload -- asking people to look at even more data sources than they already are doing is something not always met with grins.

Given that I fully expect a situational awareness regime involving social media to be highly recommended by the coming service assessments, that will have to change.

I use social media sources whenever I have time to, especially when the "usual" sources are coming up empty.

I believe the PAH office actually divides the region into sections for big events - one person and their partner is responsible for southeast MO - one is responsibility for southern IL - and so on.

That sounds pretty typical. You'll generally have an array of staffing plans to use as a template, involving a different number of people based on the perceived threat. One dedicated radar operator is a necessity even in sub-warning events. In a small warning event, you can likely get away with one dedicated radar operator and one person keeping sort of a second eye on things too. In the big outbreak events, you may need three dedicated operators just for severe (add one for flash flooding too). Not all offices use the "teammate" policy (one forecaster on radar/D2D, one forecaster does the typing / sending of the statement) -- some prefer just to let one person handle both ends of things.

That's just for the radar operators, of course -- you still need people handling grids, incoming phone calls, data collection, TAFs, LSRs, and so on.

Splitting people up geographically is called sectorizing, and is essential in larger events. You need to make sure every storm is covered, and everyone knows their specific role.

[The Great Zo]

There is a difference in the damage caused by tornadic winds and straight-line winds, but the vertical component has little to do with it. Instead, it's the change in wind direction that causes additional damage.

If you have a tree that is hit by a southerly wind that is above the yield point but below the tensile failure or buckling point, the northern side of the tree will undergo compression and the southern side of the tree will undergo tension. The cellulose fibers in wood typically handle tension much better than compression and on the lee side of a tree that is bending significantly under wind load, you will find that compression fractures occur. This is where the cells actually rupture, but the compression isn't enough to actually buckle the tree. However, the cellular damage decreases the tensile strength of the wood so that when the winds change direction, the tree will more readily snap along the fractures. A straight line wind of the same magnitude would leave the tree bent from the compression fractures, but still standing.

This same effect is seen in hurricanes due to the change of direction of eyewall winds.

Everything you're saying makes a lot of sense, and I thank you for your post. With that said, in a squall line moving a mile a minute, a 20-MPH circulation isn't going to actually give you ground-relative winds of different directions impacting things like you describe. There will probably be some turning in direction, but not a complete reversal.

Which is another point that should be made about spin-ups. The surveys are usually rather inconclusive, since the winds (while caused by a circulation) affect ground targets in what's essentially a straight-line motion. The on-the-ground forensics aren't enough to add things up by themselves.

You're spot-on for situations where the circulation is dominant over the forward motion of the parent storms.

[blizznd]

As a NWS met....one of the huge pet peeves of mine is that technology used at many TV stations in our area (small market northern Plains) have not kept up to NWS polygon. As a met on radar, I take pains to only include areas I think are warranted.... and then only to see pop up on a scroll on TV.....the basic TOR/SVR warning for XX county til xx pm. No mention of what part of the county, what cities, etc. The scrolling technology used goes off the FIP code. For example use Cass county ND where Fargo is located. Fargo is located in southeast part of the county and the county is quite large in size. I have a storm headed northwest and will clip far northwest Cass county (30 miles away from Fargo).... The scroll on TV will say a warning for Cass county.... no mention of what part or what cities included. Same for Grand Forks county ND. Grand Forks city is on the far eastern end, whereas the county stretches some 30 miles west. We issue a TOR for western Grand Forks county, the scroll on TV will say a TOR warning for Grand Forks county and a little map will pop up with the county red. In TOR warnings there is usually one TV met cut in at the start of the TOR warning, but no wall to wall up here in TOR warnings. The TV met does well in explaining only western part of the county, but that darn scroll which most people keep seeing has the whole county. Thus it is no wonder why folks in the city of Grand Forks feel they are warned too much. NWS issues the right product and doesnt have the city in any warning, but the way the local TV market scrolls info the TV viewing public reads the whole county is in a TOR. We have got to spread better technology to small TV markets.

In regard to Severe Thunderstorm Warnings....one station scrolls A Thunderstorm warning is in effect for xx county... Severe is left out. No wonder we get calls asking why a warning is not out for lightning.

I do say NWS going to FB is a good thing. I used it a lot in one recent evening when the threat for severe weather was high. Used it to talk about possible development areas and timing. I got many good responses back.

On thing on sires....our county does do sirens on Severe T-storm warnings if we have 70 mph winds or more in the text. This is due to a storm back about 10 years ago when 110 mph straightline winds blew through and no sires went off because a TOR wasnt out.

Dan

[MGorse]

As a NWS met....one of the huge pet peeves of mine is that technology used at many TV stations in our area (small market northern Plains) have not kept up to NWS polygon. As a met on radar, I take pains to only include areas I think are warranted.... and then only to see pop up on a scroll on TV.....the basic TOR/SVR warning for XX county til xx pm. No mention of what part of the county, what cities, etc. The scrolling technology used goes off the FIP code.

In regard to Severe Thunderstorm Warnings....one station scrolls A Thunderstorm warning is in effect for xx county... Severe is left out.

It is not only the small market TV stations, as both of these things you mentioned also occurs in the Philadelphia, PA region TV market.

[blizznd]

It is not only the small market TV stations, as both of these things you mentioned also occurs in the Philadelphia, PA region TV market.

That is suprising... glad to know the Fargo TV market isnt too far behind the times That is fustrating though to me....the polygon warning was one way

for us to reduce the FAR area.....but yet so many "old" systems are still based on county FIP codes and thus all the effort we do to pinpoint gets wasted.