Map Stories – April 27, 2014 Tornado (Mayflower and Vilonia, AR)


This Entergy substation SW of Mayflower received a direct hit from yesterday's tornado.  Click the image to view the preliminary track of the storm

This Entergy substation SW of Mayflower received a direct hit from yesterday’s tornado. Click the image to open an interactive map for this point as well as other areas along the damage path.

It’s April again and that unfortunately means it’s tornado season.  Clicking the image to your right will take you to an interactive story map showing the tornado path for this storm, with links to videos, pictures and other supporting information.  The story shows a step by step view over a 60 minute period during the life of this tornado.

This storm rotation path is based on NWS Weather Radar observations.  Points were added to depict the center of rotation at roughly five minute intervals as the radar updated.  Those points are then connected to depict an approximate rotation path, which is then buffered on each side to depict a 1/4 mile, 1/2 mile and 1 mile wide area.  The tornado width has not yet been determined by NWS Little Rock, however these ranges help to depict likely impact areas, with the most likely impact area being the 1/4 mile wide corridor (red area), followed by the orange area (1/2 mile wide corridor) and finally the 1 mile wide corridor (yellow area).

Additionally, the damage photos and videos were added to the story map AFTER the damage path was created.  This means that as videos and pictures are reported to/by local media, social media, emergency managers, etc., the location of the photos can be compared against the preliminary estimated damage path in order to verify the accuracy of the information.

The preliminary impact corridor is essentially serving to identify the hazard zone.  On top of that map, information on community facilities, demographics, etc can be overlaid, thus creating an realtime operational impact analysis or risk assessment.  That in turn can be used to help refine the response to the hazard so the community can respond and then recover as fast as possible.

When you don’t know the impact zone of any natural disaster, it’s nearly impossible to get your arms around the situation and make sure that the appropriate resources are being called upon to assist in the response.  However when the impact zone is clearly identified, it can facilitate improved collaboration and effectiveness of the response – from individual citizens and neighbors, to community groups, charities and finally local, state and national officials.

If you find this resource helpful, please pass it on to others.  Thanks.

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Interactive ESRI Story Maps view of the April 27, 2014 tornado that impacted Mayflower and Vilonia, AR.

 

5/15/2013 – DFW Area Tornado Outbreak (Granbury and Cleburne Tornadoes)


– At least 6 dead in Hood County –
Preliminary Ratings Per NWS Fort Worth – Granbury – EF-4; Cleburne EF-3

GranburyAerialDamage_NWSFortWorth

Aerial damage photo from the area hardest hit by the Granbury tornado. Photo via National Weather Service – Fort Worth Facebook Page – https://www.facebook.com/US.NationalWeatherService.FortWorth.gov

On the evening of May 15th, strong to violent tornadoes went through portions of Hood County and Johnson County, TX.  Six people were killed in the Granbury area from this storm, and multiple tornadoes were produced as the storm cell tracked through the region.   The maps below were created from radar images, and depict the rotation paths of the tornadoes as they impacted areas near Granbury and Cleburne, TX.  As you can see from the images, the storms progressed from WNW to ESE (you can look at the timestamps), however the tornadoes tracked from south to north while they were on the ground.  I’m sure this scenario has occurred before, but the differences between the storm motion and the path of the tornadoes themselves could be lending to some of the initial confusion in reporting areas impacted.CombinedRotationPaths

Granbury Tornado (Hood County, TX) – As of the morning after the storm, authorities in Hood County were reporting -6- fatalities from the storm, with nearly 100 injuries.  Based on radar observations, correlated to scanner reports of streets impacted, below is some preliminary information on primary impact area.  The hardest hit area was located south and east of Granbury, TX on the north side of Lake Granbury.  Some areas / roads in the area most impacted include the area near Rancho Brazos Estates / Tumbleweed Lane (http://goo.gl/maps/HRxfL – Google Maps Link).  There were a number of tweets reporting structural damage, homes collapsed.  Looking more closely at some of the buildings in this area show that many homes are mobile homes, likely contributing to the high casualty numbers.

Tornado Debris Signature ~810pm CT depicting debris from the Granbury Tornado

NWS Dual-Pol Radar image showing Correlation Coefficient (CC) and the Tornado Debris Signature ~810pm CT.  Low values of CC in areas with high rotation (likely tornado areas) are consistent w/ debris being produced by a tornado on the ground.  This location correlates with law enforcement and social media reports describing the hardest hit areas. (click for larger image)

RotationPath_HoodCounty_Imagery

Rotation Path for the 5/15/13 Tornado – Hood County, TX (Aerial – Click for larger image)

Bing Maps imagery showing the area hardest hit by the Granbury tornado.  Note the concentration of mobile homes in the center of the image.  Many homes were "wiped off their foundation".  Because of their vulnerability to winds, my guess is that these homes were some of the hardest hit in the area.

Bing Maps imagery showing the area hardest hit by the Granbury tornado. Note the concentration of mobile homes in the center of the image. Many homes were “wiped off their foundation”. Because of their vulnerability to winds, my guess is that these homes were some of the hardest hit in the area. (Click for larger image)

RotationPath_HoodCounty_Roads

Rotation Path for the 5/15/13 Tornado – Hood County, TX (Street Map – Click for larger image)

Damage photo via Twitter (WFAA screenshot)

Later in the evening, another large tornado (reported by spotters to the NWS as a mile-wide tornado) impacted areas South and West of Cleburne, TX.  One of my best friends from College lives there, so I’m quite familiar with that part of town.  There is a lot of new residential development in that part of town – single story homes, most without basements, however the relative age of the homes hopefully means that they’re built to withstand stronger winds.  The roofs in most of this area are hip roofs which hold up better to stronger winds.  Here’s a link to Google Maps to Southwestern parts of Cleburne (http://goo.gl/maps/JfMvA)  I’ll update more as I hear more from the Cleburne area, but the radar images did not look good.  Thankfully though, the strongest radar images occurred outside of town.  Below are the timestamps (UTC) showing the rotation path through the Cleburne area.

Picture of mile wide tornado (backlit from lightning) near Rio Vista, TX – via Fox4 Weather Facebook Page

RotationPath_Cleburne_Imagery

Rotation Path for the 5/15/13 Tornado – Cleburne, TX (Aerial – click for larger image)

RotationPath_Cleburne_Roads

Rotation Path for the 5/15/13 Tornado – Cleburne, TX (Street Map – click for larger image)

Damage to houses along Lakecrest Court in Cleburne (image from WFAA).  For more pictures from WFAA, visit http://www.wfaa.com/home/HD-chopper-8-gets-first-look-of-tornado-damage-in-Cleburne-207684041.html?gallery=y&c=y

Damage to houses along Lakecrest Court in Cleburne (image from WFAA). For more pictures from WFAA, visit http://www.wfaa.com/home/HD-chopper-8-gets-first-look-of-tornado-damage-in-Cleburne-207684041.html?gallery=y&c=y.  Note: Lakecrest Court is located almost exactly at the 0215 UTC location dot on the previous map, depicting the approximate path of the tornado.

Central Plains Blizzard: Snow Amounts Likely to Take Many By Surprise


A Blizzard Warning and Winter Storm Warning has been issued parts of the Southern and Central Plains, the second such blizzard in a week for some residents.  However a concept in disaster preparedness can be readily displayed with the forecast for this event.  Currently, the National Weather Service is forecasting a foot as the upper limit to the snowfall values in Kansas and 15″ as the upper limit to snowfall values in extreme Northeastern part of the Texas Panhandle.  But the highest snowfall totals for this storm could be much much higher….

Recently, the NOAA Hydrometeorological Prediction Center (HPC) began issuing probabilistic snowfall graphics (shown below) that show snowfall forecasts where snowfall values are exceeded 90%, 75%, 50%, 25% and 10% of the time.

prb_48hsnow_50prcntil_2013022412f048_sm

HPC 50th Percentile Snow Forecast
(Click for larger image)

prb_48hsnow_90prcntil_2013022412f048_sm

HPC 90th Percentile Snow Forecast
(Click for larger image)

Essentially a 50th percentile snow forecast is the forecast that 50% of the time the amounts will be higher and 50% of the time, the amounts will be lower.  For planning purposes, this is the likely amount forecasted if you’re going to play the middle of the road.

However the 90th percentile forecast is quite different.  It shows the amounts that will be exceeded only 10% of the time.  While many people want to forecast snow amounts accurately, the 10% probability event is a great resource to “Plan for the worst” and the 50% probability event is “hoping for the best”.

The wild card in events like this is thunder snow. Essentially, areas where thunder snow occurs can receive locally higher snowfall amounts. The snow probabilities point to this potentiality, although the bands of intense snowfall will not cover the entire area. Depending on where the most intense bands set up, it will dramatically impact the amounts of snow received in those areas. This again points to the importance of the 10% exceedance threshold. Most people will receive snow amounts closer to the 50th percentile amount, but there will be pockets where people receive substantially higher amounts.

Snow_BlizzardKansas_Feb24

Comparison between NWS forecast (left) and HPC 90th percentile / 10% exceedance forecast (right) Current as of 0800CT on 2/24/2013

You may be saying right now, “that’s great but I hate math and hate probabilities”.  Communicating potential risk, especially in low probability, high impact events is critical for anticipating the worst and taking protective action while hoping for the best.  If there was a 10% chance of an intruder in your house, going after you and your family, would you take protective action?  If there was a 1 in 10 chance that you could lose your job, would you start developing a backup plan?

We’ll see how this specific event unfolds, but the current forecast (left in map above) isn’t even at the levels depicted in the 50th percentile event (likely underestimating snow  amounts).  Between that and the incredible disparity between the forecast and 10% potential snowfall amounts, this is a classic example where people can and likely will be caught surprised by the event.

Power Outage Blacks Out Super Bowl Advertising??? Think again. “Not a Problem…”


Along with millions of others, you probably saw the power outage in the Super Bowl. During the stoppage in play, CBS did not air additional advertised commercials, but that didn’t stop advertisers from quick thinking / responding on their toes. The outage occurred at about 7:37 local time, and within 11 minutes @oreo posted one of the first major advertising tweets of the outage.  When all was said and done, more than 14,000 retweets had occurred and 4500+ people saved the tweet in their favorites.  The ad was simple and to the point, and connected with so many who were “left in the dark”.

Just take a look and decide for yourself – How effective is this $0.00 ad compared to the nearly $4 million for a 30 second broadcast advertisement in this year’s Big Game?

Award for advertiser thinking on their feet

Is the worst flu season in the past several years? Google says it is and here are the maps to prove it.


Graph of Google Flu Trends for the United States - As of 1/10/2013

Graph of Google Flu Trends 2012-2013 Flu Season in the United States – As of 1/10/2013

Over the past several days, there have been an increasing number of stories about this year’s flu season (2012-2013 flu season) being one of the worst in several years (Huffington Post, Boston Herald, NY Post).  There are even stories of schools closing down for a day because of high absenteeism because of illness (Oklahoma, Minnesota)  Starting in 2003, Google began tracking search terms because there was a correlation between words people were searching for and the intensity of the flu season.  As a result, the site http://www.google.org/flutrends/ was created.  One of the best items with this site though is that Google allows users to download data (CSV) for analysis.  As a result, the following maps were created to depict the strength of this year’s flu season in comparison to previous years.  As you can see, the 2003-2004 (H3N2) season and the 2009-2010 (H1N1) season are the worst seasons according to Google flu trends data since 2003 when the information was first tracked.

Additionally, the Google flu trends data is tracked and updated daily, while the data from state health organizations and the CDC is usually 1-2 weeks behind the actual occurrences.  This is for a number of reasons (onset of symptoms vs seeking treatment, delay in reporting, etc), but the Google trends charts are very similar to the charts disseminated by the CDC.  With this in mind, expect a surge in stories from states and localities beginning to implement health emergency plans for extremely high levels of flu activity.

Map Google Flu Trends Data - Showing Worst Season Since 2003-2004

(Above) Map Google Flu Trends Data – Showing Worst Season Since 2003-2004

GoogleFluTrends_PercentOfRecordYear

(Above) Current (As of 1/10/13) Google Flu Trends Values Relative to Previous Record (2003-2013)

Using Digital Maps to Study Digital Preparedness and History – WNYC


New Tech City: Using Digital Maps To Study Disaster Preparedness and History – WNYC.

Genius!!  Pure genius!  This is a major challenge with disaster preparedness today, and learning lessons from history and previous disasters are essential to minimizing impacts from future disasters.  Case and point NYC… With Hurricane Sandy, the storm surge was referenced as being a record surge.. even higher than the hurricane that occurred in 1821.  This still begs the question – “what if the hurricane of 1821 happened again today… what would the impact be?”  Additionally, as stated in http://stevengoddard.wordpress.com/2012/11/15/1821-hurricane-struck-new-york-at-low-tide/, the 1821 storm actually struck at LOW tide.. meaning the Category 3 storm then could have produced a tide level even higher than Sandy had it struck 12 hours earlier or later.  Again.. this means for preparedness… “THIS COULD HAPPEN…”   Again, great advances in technology, now we just have to put it together to answer the core questions… what if it happened again today, and how could we be more prepared…

Mapping Severe Weather Probabilities


Have you ever wondered if there are patterns to where and when severe weather occurs in the United States?  There are days where we see tornado watches, severe thunderstorm warnings, reports of high wind, hail and even tornadoes.  But, what if you could see these patterns visually – say for example on a map of the country.  Well, University of Oklahoma Ph.D. candidate Patrick Marsh has just created an incredible set of animations hosted on Youtube depicting daily severe weather probabilities over a 30 year period.

You can read more on Patrick’s most recent posts at the links below:

Storytelling with Weather



I love how maps can be used to tell a story.  This fact just became easier with a recent addition to ESRI’s ArcGIS Online tools.  When you create a web map in ArcGIS Online, you can make it into a web application using a number of templates.  One of the most recent additions is the Tabbed Storytelling template.  There are still a few bugs that need to be worked out (like customizing the “Add Title Here” area), but all in all, it’s a great addition to the templates used by ArcGIS Online.  It took me 45 minutes to an hour to put together the map at the following link.

http://www.arcgis.com/apps/Compare/storytelling_tabbed/index.html?appid=86756c43ae9147ca8baf3581764d0c8f

What’s even more amazing about this is that you can create separate maps that can paint different parts of the puzzle, but it allows you as a user or your customers to view the comparison between the maps.  This is great because it allows individuals to make the logical connections between the maps which ends up in having more people ask additional questions.  These questions drive curiosity but they also tend to stick in people’s minds. Continue reading

Your Response to Disasters… Does It Really Make A Difference?


Over the past year, we’ve been inundated with story after story of Billion Dollar Natural Disasters.  We have come to hear about these events on our smartphones, tablets, laptops, Twitter, Facebook, and broadcast news reports.  But when it comes down to it, when it happens in another community, it sounds bad, but it’s really just hard to understand how significant of an impact it really is.  On the flip side of the coin, when it happens to you and your town, or even more locally – to your family, most people would end up being overwhelmed with the situation, not knowing how to respond.  Let’s look at other areas in life – what about the loss of a family member – a parent, a sibling, a child?  How many people have lost jobs in the past year?  Have you been affected, or has this happened as well to your family or friends?  Do you know someone who seemed to have the world in front of them and then in an instant, it was all turned upside down? Continue reading

Mapping the Zombie Apocalypse


What would you do???

When we think of mapping using GIS for disasters and emergencies, we think of tornadoes, floods, hurricanes, earthquakes and the like.  When we think of education, we often think of the same old off-the-shelf material from a book that we just take and share thinking we’re teaching.  However in both cases, we miss out on one of the joys of education.  Applying knowledge from one discipline or area to other areas of life…

Many of my followers on Twitter (Follow @emgis on Twitter) and this blog know of the CDC’s preparedness campaign from earlier this year on Zombie Preparedness – “Preparedness 101: Zombie Apocalypse“.  However most people who are familiar with the preparedness campaign are from the Social Media for Emergency Management (#SMEM hashtag on Twitter) community.  Most of them are not GIS people and haven’t seen how Geographic Information Systems (#GIS hashtag on Twitter) can improve our preparedness for Zombies (and for other disasters…)  Additionally, the Connected Principals Chat community (#cpchat hashtag on Twitter) could benefit from this post because it provides another way to engage students and parents on a number of levels.  You may not use zombies for important information to share, but please take a look at these examples and think of how you can apply this to your discipline and the content that you find important to share with others.

Enter the Zombie Apocalypse… Continue reading