US and Canadian Strong & Violent Tornadoes, 1980-2009
01-28-2017 12:23 PM - last edited 02-14-2017 15:58 PM
01-28-2017 12:23 PM - last edited on 02-14-2017 03:58 PM by mackenzie_lyng
Strong & Violent tornadoes have F3 and greater damage ratings on the original Fujita Scale. A multi-tab visualization suite is provided for US and Canadian Strong & Violent tornadoes, using separate source, non-common datasets.
One tab is dedicated to interactively map the starting locations for individual events, while additional tabs provide interactive seasonal and annual summaries.
DATA SOURCES & DATA PREP
Publically available Environment Canada & US Storm Prediction Center historical tornado datasets are used where years overlap (1980-2009). Both datasets were wrangled to ensure common element type & form, and to add fields that support lookup tables to drive user interactivity and cross-filtering. Various DAX Measures were created to support a range of dynamic calculations.
User Slicer, Legend, and Visualization Element mouse selections drive cross-filtering and dynamic calculations on all tabs. Users can also filter by Country.
- Tab ‘Map’: Each bubble shows the starting lat/lon location for the event, color coded by F-Scale rating, along with a Monthly Summary. Users can multi-select Months and F Scale ratings for custom analysis.
Users can mouse over/click on any bubble for more event details with tooltips and in the Matrix visualization.
- Tab ‘Annual Summary’ dashboard.
- Tab ‘Seasonal Summary’ dashboard.
The visualizations reveal:
- In the USA, high-end events generally peak in spring, with a second, smaller peak often appearing in late fall.
- In Canada, high end events peak in summer.
- For this dataset we see variability of US events from a monthly, seasonal, and annual perspective, with an even greater annual variability of high-end Canadian tornadoes.
- Maps allow the user to investigate deeper into regional events. Multiple month selections support flexible timeframes, while auto-zooming highlights where events occur (users can also zoom manually at anytime to investigate event clusters or regions). These functions allow users to seek/define their own stories.