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.

 

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Deadly Tornadoes Cut Through Central Oklahoma (Edmond, Carney, Norman, Bethel Acres, Shawnee)


Earlier this evening, several supercells erupted in Central Oklahoma, producing several strong to violent tornadoes.  These tornadoes impacted communities such as Edmond, Carney, Norman, Bethel Acres and Shawnee.  Much of the attention now including prayers have been focused on those impacted in a mobile home park directly in the path of the tornado where at least one fatality has occurred.

The following link goes to an interactive map showing the approximate paths of the three most significant tornadoes that impacted Central Oklahoma.  The map has a bookmark feature where you can view the Edmond, Carney and Norman to Shawnee tornadoes.  Similar tornado path maps have been very helpful and highly accurate for other significant tornadoes events over the past several years.

Click on the graphic to launch an interactive map.

Click on the graphic to launch an interactive map. The map contains bookmarks for the 3 tornadoes as well as an address lookup feature.

This information is unofficial information, but is based upon NWS Radar scans and uses the National Climate Data Center Weather/Climate Toolkit (NCDC WCT) and ESRI’s ArcGIS Online.  For official storm survey results, please follow the National Weather Service in Norman, Oklahoma (@NWSNorman).  In the coming days, the National Weather Service will be performing storm damage surveys.  When more information is made available, I’ll be linking to those products.

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.

Preliminary Path Estimate for the 4/13/2012 Norman, OK Tornado


Preliminary likely tornado path created at 600pm CT

This post covers the Friday 4/13/2012 tornado that impacted Norman, OK in the evening hours.  The tornado outbreak continues into Saturday.  For the newest blog post covering the Saturday, 4/14/2012 Tornado Outbreak with interactive map, Click Here. (THIS INCLUDES THE PATH OF THE WEDGE TORNADO SW OF SALINA, KS)

4/13 – 1028pm CT – Added link to NWS Norman preliminary UNOFFICIAL track map from @NWSNorman

4/13 – 928pm CT – Updated interactive map to include links to media video and photo of damage with locations.  The locations verify quite well with the initial map points

It’s incredible to think of how today progressed…. First I shared a presentation on this topic to several of my peers around the country to share a methodology with the hopes of helping people tomorrow and in other tornado outbreaks, and the next thing I know, I’m talking to my brother in Oklahoma who is trying to get home to Norman after school, with a tornado warning for his home town.  It’s amazing to see the impact of how technology and information can be brought together to help protect lives.  I ended up helping guide him home to keep out of the storm while the tornado passed less than 1/2 mile from his house, telling him to stay put and keeping him out of harm, but still guiding him home.  Thankfully everyone in the family is safe, but it’s incredible to know that it makes a difference so close to home.

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Tornado Fatailities and the NWS Dual-Polarization Radar Upgrades


One of the fatalities occurred in this area near Jackson Gap. The NWS warnings for this storm were very clear, telling people to “seek shelter underground” and that a debris signature was appearing on radar.

Some people might ask is it worth it to upgrade the National Weather Service (NWS) radars to this “new” dual-pol technology.  While only 25% of the 160 radar sites around the country have been upgraded, the performance in the March 2, 2012 Tornado Outbreak is quite an impressive statement to the effectiveness of the technology.

During the March 2nd tornado outbreak, many of the tornadoes occurred in areas where the radars have already been upgraded.  When the debris was detected by the dual-pole technology, meteorologists could enhance their tornado warnings, confirming that a damaging tornado was indeed on the ground.  These signatures are essentially as good as visually confirmation of the tornadoes being on the ground.  The technology works because when the radar beams hit debris (leaves, shingles, branches, parts of houses, etc), there is a different signature from what is seen by the radar.  In the graphic above, you can see the blue area in a circle.  This area means that the radar is seeing a “different” signature from the surrounding areas.  When this is in the same location as strong rotation as seen by the doppler velocity products, it is essentially a confirmation of a tornado on the ground at the time of the radar sweep, or just before that time.

This will be significant with difficult-to-see tornadoes, especially ones that are either rain-wrapped or occurring in the overnight hours. Continue reading

Tools for Tornado Response – Case Study from the May 24, 2011 Tornado Outbreak


2011 has been a prolific year for major tornado outbreaks.  We know of the storms that have impacted our cities and towns across the country.  We also are generally familiar with the devastating outbreaks affecting cities like Joplin, Tuscaloosa, St. Louis & Raleigh.  There is one outbreak though that many people overlooked because of the timing of the event.  This outbreak occurred in Central Oklahoma, produced 2 EF-4 tornadoes and one 60+ mile long EF-5 tornado.  However, due to the timing of the event, most of the nation’s focus was elsewhere on another community that was severely impacted.

On May 24th (2 days after Joplin), a number of tornadoes impacted central Oklahoma (NWS – Norman Event Summary).  The most powerful of these was rated as an EF-5 tornado impacting the El Reno area.  That storm was not only sampled by mobile and fixed weather radar, but the outer edges of the tornado actually were directly measured by the Oklahoma Mesonet station at El Reno (see images below).

The mesonet station measured a wind gust to 151mph (click on the photo to the left to visit the AMS blog).  There are nearly 120 stations throughout Oklahoma as a part of the Oklahoma Mesonet.  This information proves invaluable to having field verified weather observations that are directly measured.  Even though this tornado was on the ground for nearly 60 miles and had a width of 1 mile, direct measurements of this nature are not usually seen. There were 9 fatalities and nearly 200 injuries with this storm.

At nearly the same time as the El Reno/Piedmont storm was hitting those areas, two other storms were rolling through Central Oklahoma, further to the Southeast.  These two storms ended up tracking to less than ten miles from Norman Oklahoma where the National Weather Center is located – housing some of the nation’s brightest and best minds in severe weather research. Continue reading

Critical New Weather Radar in the Pacific NW


Earlier this month, the National Weather Service installed a new Weather Radar at Langley Hill, WA.  This new weather radar is located on the Washington coast and will significantly improve radar coverage for the Pacific Northwest including offshore radar coverage.  In much of the rest of the country, we have the luxury of seeing what impacts occur as storms progress through the country. However in the Pacific Northwest, they are the first in line to be impacted by major winter storms (similar intensity to Atlantic Cat 2 or 3 hurricanes).

Check out the Cliff Mass Weather Blog for a great set of links reviewing the new resource (also on Twitter  @CliffMass).

Status of Nationwide Weather Radar Upgrades


The National Weather Service is currently in a multi-year upgrade of their WSR-88D weather radars.  This technology upgrade is called Dual Polarization radar, and is sometimes referred to as Dual-Pole technology.  (Learn more from Nexrad Now Issue 20 – Dec 2010)

“In the spring of 2003 the National Weather Service Office of Science and Technology tasked the National Severe Storms Laboratory with providing data collection and analysis to support a WSR-88D dual polarization decision briefing to the NEXRAD Program Management Committee. The Joint Polarization Experiment (JPOLE) project was designed to evaluate the engineering design and data quality of the polarimetric KOUN WSR-88D radar and demonstrate the utility of polarimetric radar data and products to operational users. The NSSL JPOLE experiment demonstrated the performance improvements dual polarization provided in rainfall estimates, hydrometeor classification, and general data quality.” (From NOAA ROC)

The NOAA Radar Operations Center has created a status upgrade map in PDF form that shows the weekly progression of the upgrade process.  When the upgrade is occurring, the radar site will be down for roughly two weeks.  As of 9/30/2011, there are 7 sites across the US that have received this upgrade including Vance AFB, OK; Wichita, KS; Pittsburgh, PA; Portland, OR; Phoenix, AZ; Morehead City, NC; and the new radar at Langley Hill, WA.

To find when your radar will be upgraded, check out the full deployment schedule from NOAA ROC Dual-Pole page.

NCDC Weather and Climate Toolkit


This image shows the full extent of Hurricane Katrina as the storm was making landfall in Louisana. Image is a NEXRAD Level-III Base Reflectivity.  This image shows the May 3rd, 1999 Moore Oklahoma tornado on radar. Plotted is the Tornado Vortex Signature and the image is the base reflectivity and smoothed.

Many people are looking for weather data (especially higher resolution radar data) that supports response and recovery activities as well as research into previous significant weather-related natural disasters.  The National Climate Data Center (NCDC) Weather and Climate Toolkit (WCT) allows users to interact with an incredible amount of data (historical or current) and display that within the Java based application.  The website provides solid how-to guides for accessing current data, ordering historical datasets and using the various functions of the tool.  Continue reading