Context

This data set contains the number of confirmed tornadoes for each state for each year and their responding affects.

Content

Current table includes number of confirmed tornadoes in each state for each year from 1951 to 2019. Future datasets will be related to Fujita/Enhanced Fujita rank, total damage (reported and inflation corrected), and fatalities/injuries. Data is from National Centers for Environmental Information's Storm Events Database.

Inspiration

I am curious about the trend of sever weather occurring in the United States over time. This started with tornadic events but will evolve to severe thunderstorm and hail events as well.

Tornado TracksThis feature layer, utilizing data from the National Oceanic and Atmospheric Administration (NOAA), displays tornadoes in the United States, Puerto Rico and U.S. Virgin Islands between 1950 and 2024. A tornado track shows the route of a tornado. Per NOAA, "A tornado is a narrow, violently rotating column of air that extends from a thunderstorm to the ground. Because wind is invisible, it is hard to see a tornado unless it forms a condensation funnel made up of water droplets, dust and debris. Tornadoes can be among the most violent phenomena of all atmospheric storms we experience. The most destructive tornadoes occur from supercells, which are rotating thunderstorms with a well-defined radar circulation called a mesocyclone. (Supercells can also produce damaging hail, severe non-tornadic winds, frequent lightning, and flash floods.)"EF-5 Tornado Track (May 3, 1999) near Oklahoma City, OklahomaData currency: December 30, 2024Data source: Storm Prediction CenterData modifications: Added field "Date_Calc"For more information: Severe Weather 101 - Tornadoes; NSSL Research: TornadoesSupport documentation: SPC Tornado, Hail, and Wind Database Format SpecificationFor feedback, please contact: ArcGIScomNationalMaps@esri.comNational Oceanic and Atmospheric AdministrationPer NOAA, its mission is "To understand and predict changes in climate, weather, ocean, and coasts, to share that knowledge and information with others, and to conserve and manage coastal and marine ecosystems and resources."

TornadoesThis feature layer, utilizing data from the National Oceanic and Atmospheric Administration (NOAA), displays tornadoes in the United States, Puerto Rico and U.S. Virgin Islands between 1950 and 2024. Per NOAA, "A tornado is a narrow, violently rotating column of air that extends from a thunderstorm to the ground. Because wind is invisible, it is hard to see a tornado unless it forms a condensation funnel made up of water droplets, dust and debris. Tornadoes can be among the most violent phenomena of all atmospheric storms we experience. The most destructive tornadoes occur from supercells, which are rotating thunderstorms with a well-defined radar circulation called a mesocyclone. (Supercells can also produce damaging hail, severe non-tornadic winds, frequent lightning, and flash floods.)"EF-5 Tornado (May 22, 2011) near Joplin, MissouriData currency: December 30, 2024Data source: Storm Prediction CenterData modifications: Added fields Calculated Month and DateFor more information: Severe Weather 101 - Tornadoes; NSSL Research: TornadoesSupport documentation: SPC Tornado, Hail, and Wind Database Format SpecificationFor feedback, please contact: ArcGIScomNationalMaps@esri.comNational Oceanic and Atmospheric AdministrationPer NOAA, its mission is "To understand and predict changes in climate, weather, ocean, and coasts, to share that knowledge and information with others, and to conserve and manage coastal and marine ecosystems and resources."

• Update Frequency: Weekly

Data from this dataset can be downloaded/accessed through this dataset page and Kaggle's API.

Context

Severe weather is defined as a destructive storm or weather. It is usually applied to local, intense, often damaging storms such as thunderstorms, hail storms, and tornadoes, but it can also describe more widespread events such as tropical systems, blizzards, nor'easters, and derechos.

The Severe Weather Data Inventory (SWDI) is an integrated database of severe weather records for the United States. The records in SWDI come from a variety of sources in the NCDC archive. SWDI provides the ability to search through all of these data to find records covering a particular time period and geographic region, and to download the results of your search in a variety of formats. The formats currently supported are Shapefile (for GIS), KMZ (for Google Earth), CSV (comma-separated), and XML.

Content

The current data layers in SWDI are:
- Filtered Storm Cells (Max Reflectivity >= 45 dBZ) from NEXRAD (Level-III Storm Structure Product)
- All Storm Cells from NEXRAD (Level-III Storm Structure Product)
- Filtered Hail Signatures (Max Size > 0 and Probability = 100%) from NEXRAD (Level-III Hail Product)
- All Hail Signatures from NEXRAD (Level-III Hail Product)
- Mesocyclone Signatures from NEXRAD (Level-III Meso Product)
- Digital Mesocyclone Detection Algorithm from NEXRAD (Level-III MDA Product)
- Tornado Signatures from NEXRAD (Level-III TVS Product)
- Preliminary Local Storm Reports from the NOAA National Weather Service
- Lightning Strikes from Vaisala NLDN

Disclaimer:
SWDI provides a uniform way to access data from a variety of sources, but it does not provide any additional quality control beyond the processing which took place when the data were archived. The data sources in SWDI will not provide complete severe weather coverage of a geographic region or time period, due to a number of factors (eg, reports for a location or time period not provided to NOAA). The absence of SWDI data for a particular location and time should not be interpreted as an indication that no severe weather occurred at that time and location. Furthermore, much of the data in SWDI is automatically derived from radar data and represents probable conditions for an event, rather than a confirmed occurrence.

Acknowledgements

Dataset Source: NOAA. This dataset is publicly available for anyone to use under the following terms provided by the Dataset Source — http://www.data.gov/privacy-policy#data_policy — and is provided "AS IS" without any warranty, express or implied, from Google. Google disclaims all liability for any damages, direct or indirect, resulting from the use of the dataset.

Cover photo by NASA on Unsplash
Unsplash Images are distributed under a unique Unsplash License.

We provide a dataset of tornadoes and waterspouts in Chile from 1554 to present based in chronicles, newspaper articles, social media, scientific literature and books. The database includes only those events that have been qualified as more than likely a tornado or waterspout based on a subjective qualification by the researchers. For each tornado we provide at least one geographical location point, the local and UTC hour (if known) and for most cases an estimation of the intensity based on the Enhanced Fujita damage scale.The following are the parameters contained in the database:N°: This is the entry number or identifier for each record in the file.Location: The name of the place where the weather event occurred.Latitude: The geographical latitude coordinate of the event's location.Longitude: The geographical longitude coordinate of the event's location.Date (Gregorian Calendar): The date when the event occurred, according to the Gregorian calendar.Hour (local): The local time when the event occurred.Hour (UTC): The time of the event in Coordinated Universal Time (UTC).Sound: A binary indicator (usually 1 for 'Yes' and 0 for 'No') showing whether there was a notable sound associated with the event.Hail: A binary indicator showing whether hail was a feature of the weather event.Electric Storm: A binary indicator showing whether the event involved an electric storm.Damage: A binary indicator showing whether there was any damage resulting from the event.Tornado: A binary indicator showing whether a tornado was a part of the event.Waterspout: A binary indicator showing whether a waterspout was observed during the event.Register: This column refers to the existence of some witness account or visual material of a rotating column.Max. EF Rating: The maximum Enhanced Fujita Scale rating assigned to the tornado, indicating its intensity.Analyst: The name or initials of the person who analyzed or reported the event.Fatalities: The number of fatalities (deaths) caused by the event.Injured: The number of injuries reported due to the event.Link to Documents: References or links to documents where the event is described or recorded.Sources: The sources or references from where the information about the event is derived.Comments: Additional remarks or notes about the event, providing context or extra details.

Q: Where is severe weather likely at this time of year? A: Shading on each map reflects how often severe weather occurred within 25 miles during a 30-year base period. The darker the shading, the higher the number of severe weather reports near that date. For this map, severe weather encompasses tornadoes, thunderstorm winds over 58 miles per hour, and hail larger than three-quarters of an inch in diameter. Q: How were these maps produced? A: For each day of the year, scientists plotted reports of severe weather from 1982 to 2011 on a gridded map. To reveal the long-term patterns of these events, they applied mathematical filters to smooth the counts in time and space. Keep in mind that severe weather is possible at any location on any day of the year. Q: What do the colors mean? A: Shaded areas show the historical probability of severe weather occurring within 25 miles. Meteorologists estimated these probabilities from severe weather reports submitted from 1982-2011. For each day of the year, scientists plotted reports of severe events onto a map marked with grid cells 50 miles on a side. For each grid cell, they counted the number of years with at least one report, and divided by the total number of years. To reveal the long-term patterns suggested by this relatively small dataset, they used statistical methods to smooth the data. For instance, to smooth clusters of events in time, a mathematical filter replaced the value in every grid cell with a 15-day average. Another filter extended report locations over a 25-mile-wide circle to indicate the probability that the event could have occurred at other points within that area. Q: Why do these data matter? A: Knowing when and where severe weather tends to occur through the year promotes preparedness. Residents who are alert to the possibility of severe weather are better able to respond in ways that keep them safe. These data can also help emergency response personnel plan for when and where their services may be necessary. Q: How did you produce these snapshots? A: Data Snapshots are derivatives of existing data products: to meet the needs of a broad audience, we present the source data in a simplified visual style. NOAA's National Weather Service Storm Prediction Center produced the Severe Weather Climatology files. To produce our images, we obtained the climatology data as a numpy array, and ran a set of scripts to display the mapped areas on our base maps with a custom color bar. Additional information Data for these images represents an update and extension of work first put forth by Dr. Harold Brooks of the National Severe Storms Laboratory. References Brooks, H. E., C. A. Doswell, III, and M. P. Kay, (2003) Climatological estimates of local daily tornado probability, Wea. Forecasting, 18, 626-640.Source: https://www.climate.gov/maps-data/data-snapshots/data-source/historic-probability-severe-weather This upload includes two additional files:* Historic Probability of Severe Weather _NOAA Climate.gov.pdf is a screenshot of the main Climate.gov site for these snapshots (https://www.climate.gov/maps-data/data-snapshots/data-source/historic-probability-severe-weather )* Cimate_gov_ Data Snapshots.pdf is a screenshot of the data download page for the full-resolution files.

The National Weather Service issues warnings for severe weather that are imminent or actively occurring. This layer shows shorter-term warnings for the following events:Special Marine Warnings - potentially hazardous weather conditions of short duration (up to 2 hours) that may include sustained winds or gusts of 39 mph or greater, hail 0.75” or greater in diameter, or waterspouts.Severe Thunderstorm Warnings - storms with winds of 58 mph or higher or hail 1” or greater in diameter.Tornado Warnings - imminent or active tornados.Extreme Wind Warnings - surface winds of 115 mph or greater associated with non-convective, downslope, derecho, or sustained hurricane winds are expected to occur within one hour.Flash Flood Warnings - conditions are favorable for flash flooding. It does not mean that flash flooding will occur, but it is possible.SourceCurrent Warnings: https://www.weather.gov/source/crh/shapefiles/CurrentWarnings.tar.gzSample DataSee Sample Layer Item for sample data during Weather inactivity!Update FrequencyThe service is updated every 5 minutes using the Aggregated Live Feeds methodology.Area CoveredContiguous United StatesWhat can you do with this layer?Customize the display of each attribute by using the Change Style option for any layer.Query the layer to display only specific types of weather watches and warnings.Add to a map with other weather data layers to provide inside on hazardous weather events.Use ArcGIS Online analysis tools, such as Enrich Data, to determine the potential impact of weather events on populations.This map is provided for informational purposes and is not monitored 24/7 for accuracy and currency.If you would like to be alerted to potential issues or simply see when this Service will update next, please visit our Live Feed Status Page!

A database of verified tornado occurrences across Canada has been created covering the 30-year period from 1980 to 2009. The data are stored in a Microsoft Excel spreadsheet, including fields for date, time, location, Fujita Rating (intensity), path information, fatalities, injuries, and damage costs. In cases where no data were available, values in the database have been left blank. The tornado data have undergone a number of quality control checks and represent the most current knowledge of past tornado events over the period. However, updates may be made to the database as new or more accurate information becomes available. The database has also been used to produce PNG images and an interactive KML file that can be viewed using Google Earth.

The National Weather Service (NWS) Storm Prediction Center (SPC) routinely collects reports of severe weather and compiles them with public access from the database called SeverePlot (Hart and Janish 1999) with a Geographic Information System (GIS). The composite SVRGIS information is made available to the public primarily in .zip files of approximately 50MB size. The files located at the access point contain composite track information regarding tornados, large hail, and damaging winds for the period 1950-2006. Although available to all, the data provided may be of particular value to weather professionals and students of meteorological sciences. An instructional manual is provided on how to build and develop a basic severe weather report GIS database in ArcGis and is located at the technical documentation site contained in this metadata catalog.

description: This data from the National Weather Service provides Geographic Information System (GIS) graphical representations of tornados, large hail events, and damaging wind reports in the Continental United States for the period 1950 through 2006. The data provided are in .zip files that are generally around 50 MB. Although available to all, the data provided may be of particular value to weather professionals and students of meteorological sciences. An instructional manual is provided on how to build and develop a basic severe weather report GIS database in ArcGis and is located at the technical documentation site contained in this metadata catalog.; abstract: This data from the National Weather Service provides Geographic Information System (GIS) graphical representations of tornados, large hail events, and damaging wind reports in the Continental United States for the period 1950 through 2006. The data provided are in .zip files that are generally around 50 MB. Although available to all, the data provided may be of particular value to weather professionals and students of meteorological sciences. An instructional manual is provided on how to build and develop a basic severe weather report GIS database in ArcGis and is located at the technical documentation site contained in this metadata catalog.

The National Weather Service (NWS) Storm Prediction Center (SPC) routinely collects reports of severe weather and compiles them with public access from the database called SeverePlot (Hart and Janish 1999) with a Graphic Information System (GIS). The composite SVRGIS information is made available to the public primarily in .zip files of approximately 50MB size. The files located at the access point contain track information regarding known tornados during the period 1950 to 2006. Although available to all, the data provided may be of particular value to weather professionals and students of meteorological sciences. An instructional manual is provided on how to build and develop a basic severe weather report GIS database in ArcGis and is located at the technical documentation site contained in this metadata catalog.

Although tornadoes can occur throughout the year, prime time for twisters in the U.S. is spring and early summer. Larger symbols show more violent tornadoes. Zoom into the map to see approximate tornado tracks.

A violent tornado outbreak occurred on December 10-11, 2021 in the Midwest US. One of the tornadoes, known as the Quad-State tornado, tracked across four states and devastated the downtown area of Mayfield, KY, producing high-end EF-4 damage. The data here provides a series of wind speed and direction time histories of the Quad-State tornado for 44 damaged residential houses in Mayfield, KY, which can be useful for detailed forensic analysis of the residential building damage. The data was generated using a software that performs a treefall pattern analysis method, developed by the first author. In addition to the many structural damage, the tornado damaged a large number of trees in the Mayfield area. The fall direction of the damaged trees displayed a converging pattern, caused by a rotational wind flow, which is a typical indicator of a tornado. The converging treefall pattern then can be analyzed to characterize the tornadic flow and estimate the wind field (i.e., treefall pattern analysis method). The treefall pattern analysis method simulates a series of tornadoes using an idealized Rankine vortex model and generates a virtual treefall pattern, which is used to compare to the treefall pattern observed in the field and iterated until the "best-matching" pattern is found. In order to reduce the uncertainty in the estimates, the translational speed of the tornado was estimated based on tracking the motion of the vortex signature from the nearest NEXRAD radar, and the Radius of Maximum Wind (RMW) and decay exponent of the Rankine vortex model were estimated based on the structural damage. Then, the software was used to estimate the rest of the vortex parameters and wind time history (e.g., wind speed and direction) at selected locations. More detailed description on the parameter estimation and software will be published later in the NIST Technical Note.

This feature layer is a map of all tornadoes from 1950 to present. It uses the Severe Prediction Center's Severe GIS dataset to plot all of the tornadoes that have occurred in Indiana during that time period. It is continually updated as new tornadoes occur each year.

TornadoStartLatLong_Join

This is a database of tornadoes that have affected the Huntsville Forecast area this year. National Weather Service Storm Survey information regarding the tornadoes that occurred so far in 2025 within the NWS Huntsville County Warning Area (CWA). Included are storm survey damage points with pictures where available, tornado damage paths, and estimated damage swath information where applicable.

TornadoesThis feature layer, utilizing data from the National Oceanic and Atmospheric Administration (NOAA), displays tornadoes in the United States, Puerto Rico and U.S. Virgin Islands between 1950 and 2024. Per NOAA, "A tornado is a narrow, violently rotating column of air that extends from a thunderstorm to the ground. Because wind is invisible, it is hard to see a tornado unless it forms a condensation funnel made up of water droplets, dust and debris. Tornadoes can be among the most violent phenomena of all atmospheric storms we experience. The most destructive tornadoes occur from supercells, which are rotating thunderstorms with a well-defined radar circulation called a mesocyclone. (Supercells can also produce damaging hail, severe non-tornadic winds, frequent lightning, and flash floods.)"EF-5 Tornado (May 22, 2011) near Joplin, MissouriData currency: December 30, 2024Data source: Storm Prediction CenterData modifications: Added field "Date_Calc"For more information: Severe Weather 101 - Tornadoes; NSSL Research: TornadoesSupport documentation: SPC Tornado, Hail, and Wind Database Format SpecificationFor feedback, please contact: ArcGIScomNationalMaps@esri.comNational Oceanic and Atmospheric AdministrationPer NOAA, its mission is "To understand and predict changes in climate, weather, ocean, and coasts, to share that knowledge and information with others, and to conserve and manage coastal and marine ecosystems and resources."

This is one of the upper air data sets developed for the Verification of the Origins of Rotation in Tornadoes Experiment 2 (VORTEX2). This data set includes 1986 high vertical resolution (1-second) Radiosonde Replacement System (RRS) soundings from 16 National Weather Service (NWS) rawinsonde stations and 125 high vertical resolution (6-second) MicroArt soundings from Dodge City, Kansas for the VORTEX2 2009 area and time of interest. In addition, this data set includes 1576 high vertical resolution (1-second) Radiosonde Replacement System (RRS) soundings from 17 National Weather Service (NWS) rawinsonde stations and 85 high vertical resolution (6-second) MicroArt soundings from Dodge City, KS for the VORTEX2 2010 area and time of interest. Note that Dodge City, KS radiosonde data stops at 1200 UTC on 11 June 2010 due to the start of the changeover to the RRS radiosonde. This data set covers the period from 1 May to 30 June 2009 and 1 May to 15 June 2010. The soundings were typically released twice a day (0000 and 1200 UTC). The data are in EOL Sounding Composite format (columnar ascii).

Tornado TracksThis feature layer, utilizing data from the National Oceanic and Atmospheric Administration (NOAA), displays tornadoes in the United States, Puerto Rico and U.S. Virgin Islands between 1950 and 2024. A tornado track shows the route of a tornado. Per NOAA, "A tornado is a narrow, violently rotating column of air that extends from a thunderstorm to the ground. Because wind is invisible, it is hard to see a tornado unless it forms a condensation funnel made up of water droplets, dust and debris. Tornadoes can be among the most violent phenomena of all atmospheric storms we experience. The most destructive tornadoes occur from supercells, which are rotating thunderstorms with a well-defined radar circulation called a mesocyclone. (Supercells can also produce damaging hail, severe non-tornadic winds, frequent lightning, and flash floods.)"EF-5 Tornado Track (May 3, 1999) near Oklahoma City, OklahomaData currency: December 30, 2024Data source: Storm Prediction CenterData modifications: Added fields Calculated Month and DateFor more information: Severe Weather 101 - Tornadoes; NSSL Research: TornadoesSupport documentation: SPC Tornado, Hail, and Wind Database Format SpecificationFor feedback, please contact: ArcGIScomNationalMaps@esri.comNational Oceanic and Atmospheric AdministrationPer NOAA, its mission is "To understand and predict changes in climate, weather, ocean, and coasts, to share that knowledge and information with others, and to conserve and manage coastal and marine ecosystems and resources."

This data set contains Tornadoes that occurred in Tennessee between 1950 and 2017. The data was downloaded from the NWS Storm Prediction Center.Column Names and Definitions from the NWS (pdf)om - Tornado number - A count of tornadoes during the y ear: Prior to 2007, these numbers were assigned to the tornado as the information arrived in the NWS database. Since 2007, the numbers may have been assigned in sequential (temporal) order after event date/times are converted to CST. However, do not use "om" to count the sequence of tornadoes through the year as sometimes new entries have come in late, or corrections are made, and the data are not re-sequenced.NOTE: Tornado segments that cross state borders and/or more than 4 counties will have same OM number. See information about fields 22-24 below.yr - Year, 1950-2017mo - Month, 1-12dy - Day, 1-31date - Date - in format yyyy-mm-dd formattime - Time - in format HH:MM:SStz - Time Zone - All t imes, except for ?=unkown and 9=GMT, were converted to 3=CST. This should be accounted for when building queries for GMT summaries such as 12z- 12z.st - State - Two letter postal abbreviation (PR=Puerto Rico. VI=Virgin Islands)stf - State FIPS Number - Note some Puerto Rico codes are incorrectstn - State Number - number of this tornado, in this state, in this year: May not be sequential in some years. Note: discontinued in 2008. This number can be calculated in a spreadsheet by sorting and after accounting for border crossing tornadoes and 4+ county segments.f - F-Scale - F-scale (EF-scale after Jan. 2007): values -9, 0, 1, 2, 3, 4, 5 (-9=unknown).inj - Injuries - when summing for state totals use sn=1, not sg=1 (see below)fat - Fatalities - when summing for state totals use sn=1, not sg=1 (see below)loss - Estimated property loss information - Prior to 1996 this is a categorization of tornado damage by dollar amount (o or blank-unknown; 1<$50, 2=$50-$500, 3=$500-$5,000, 4=$5,000-$50,000; 5=$50,000-$500,000, 6=$500,000-$5,000,000, 7=$5,000,000-$50,000,000, 8=$50,000,000-$500,000,000; 9=$5,000,000,000) When summing for state total use sn= 1, not Sg=1 (see below). From 1996, this is tornado property damage in millions of dollars. Note: this may change to whole dollar amounts in the future. Entry of 0 does not mean $0.closs - Estimated crop loss in millions of dollars (started in 2007). Entry of 0 does not mean 0$Tornado database file updated to add "fc" field for estimated F-scale rating in 2016. Valid for records altered between 1950-1982. slat - Starting latitude in decimal degreesslong - Starting longitude in decimal degreeselat - Ending latitude in decimal degreeselon - Ending longitude in decimal degreeslen - Length in mileswid - Width in yardsns, sn, sg - Understanding these fields is critical to counting state tornadoes, totaling state fatalities/losses. The tornado segment information can be thought of as follows:ns - Number of States affected by this tornado: 1, 2, or 3.sn - State Number 1 or 0 (1=entire track info in this state)sg - Tornado Segment number: 1, 2, or -9 (1 = entire track info)1,1,1 = Entire record for the track of the tornado (unless all 4 fips codes are non -zero).1,0,-9 = Continuing county fips code information only from 1,1,1 record, above (same om).2,0,1 = A two-state tornado (st=state of touchdown, other fields summarize entire track).2,1,2 = First state segment for a two-state (2,0,1) tornado (state same as above, same om).2,1,2 = Second state segment for two-state (2,0,1) tornado (state tracked into, same om).2,0,-9 = Continuing county fips for a 2,1,2 record that exceeds 4 counties (same om).3,0,1 = A three-state (st=state of touchdown, other fields summarize entire track).3,1,2 = First state segment for a three-state (3,0,1) tornado (state same as 3,0,1, same om).3,1,2 = Second state segment for three-state (3,0,1) tornado (2nd state tracked into, same om as 3,0,1 record).3,1,2 = Third state segment for a three-state (3,0,1) tornado (3rd state tracked into, same om as the initial 3,0,1 record).f1 - 1st county FIPS codef2 - 2nd county FIPS codef3 - 3rd county FIPS codef4 - 4th county FIPS codefc - fc = 0 for unaltered (E)F - scale rating. fc = 1 if previous rating was -9 (unknown)