2014 Indiana GIS Conference
May 8, 2014
Olivia Kellner
Ph.D. Candidate, Purdue University
Climate Specialist, Indiana State Climate Office
Photos: Doyle McIntosh
Presentation Outline:
 Founding science and
hypothesis
 Data
 Climatology
 Methods
 Findings
http://www.crh.noaa.gov/ilx/event
s/may302004/040530_rpts.gif
 Geospatial Analysis
 Methods
 Maps
 Findings
 Conclusions
http://www.srh.noaa.gov/ohx/?n=april319
74_40thanniversary
Kellner, O. and D. Niyogi, 2013, Land-surface Heterogeneity Signature in
Tornado Climatology? An Illustrative Analysis over Indiana 1950-2012, Earth
Interactions, e-view, doi: http://dx.doi.org/10/1175/2013EI000548.1.
http://www.angelfire.com/theforce/storm_chasingf5/Historical%2
0and%20Major%20Tornado%20Outbreaks%20the%20one.htm
Founding science:
 Land-surface heterogeneity: where
the land cover or land use is not
uniform across an area
 Leads to a heterogeneous boundary
layer in terms of temperature, dew
points, vertical velocities, and winds
 Can these surface
discontinuities
modify the
boundary layer
enough to impact
storm dynamics
and evolution?
Mahmood et al., 2011
Fig. 5. Inner domain average modeled (a) relative humidity, (b) dew
point temperature, (c) ground temperature, (d) two-meter
temperature, and (e) planetary boundary layer height for control, bare
soil, grassland, and forest.
Mahfouf et al., 1987
From Brown and Arnold, 1998: Figure 6. Spatial distribution for all convective
cloud masses(dots, both initial and vertically enhanced) for 34 weak synoptic
flow days, July–August, 1986–1991, in the aggregate.
From Changnon et al., 1991 Journal of Applied Meteorology
From Brown and McCann, 2004
 Indiana’s land surface, rich with physiographic
boundaries, land-surface heterogeneity, topography,
and distinct, isolated urban regions may influence the
evolution of convective weather (specifically tornado
touchdown locations).
http://media.wfyi.org/NaturalHeritage/learn/regions.html
https://ou-gisapplications.wikispaces.com/Indiana+Land+Use
http://pubs.usgs.gov/of/2004/1451/rupp/
Climatology
Geospatial Data
 Storm Prediction Center
 SPC SVRGIS webpage:
(SPC) Storm reports,
available in their Severe
Weather Database Files
 Inclusive of
 Date
 Time
 Touchdown in lat/long
 County
 F-scale
 Injuries
 Fatalities
http://www.spc.noaa.gov/gis/svr
gis/





Tornado touchdown points
States
Cities
Counties
Population Density (2010
raster file, density per square
kilometer)
 Land cover: U.S.G.S Enhanced
Historical Land-use and Landcover Data sets
 DEM: Ball State University
 Implementation of .csv files of storm data into Excel
 Sort data by:
 Date
 Time
 F-scale
 Compute tornado days and climatological data by parameters
investigated
 Month
 Year
 F-scale
 Weak (F0-F1) and Strong (F2-F5)
 Increase/decrease in annual tornado days
 Also investigated antecedent rainfall at 1, 3, and 6
month periods and ENSO phase to annual number of
tornado days
 Most active time of day
 weak tornadoes: 4-7pm LST;
 strong tornadoes: 2-4pm and
5-8pm LST;
 all tornadoes 4-8pm LST
 Majority of Indiana’s
tornadoes are weak tornadoes
(50%)
 30-year moving averages show
no increase or decrease in
annual tornado days
 30-year moving averages by
climate division show an
increase in annual tornado
days in southern most climate
divisions from 1 day a year to 3
days a year
 ENSO: rate at which ENSO
changes phase appears to
relate to more active seasons
in Indiana
 Weak relationship between 6month antecedent drought
conditions and number of
tornado days
This shift is a result of the
windshear environment more
common with strong tornadoes
Dr. T. T. Fujita, University of Chicago
 Spatial analyst tools:
 Kernel density
 Map algebra
 Slope calculator
 Conversion tools
 Analysis tools:
 Buffer
 “Select features within”
 Changes in elevation
 Change in slope of 5
degrees or more over a
distance of ~100 meters
 Change in land cover
 6 classes
 Forest
 Urban
 Agriculture
 Barren
 Wetlands/water bodies
 Range land
 Urban areas
 City centroids
 Urban area shapefiles
 Population density
 People per square
kilometer
Is this happening
here in Indiana?
http://pubs.usgs.gov/of/2004/1451/rupp/
http://jasonahsenmacher.wordpress.com/category/terrain/
~9 miles
~1 mile
Tornado “rings” ?
~Noted by Fujita in other cities
such as Chicago in early 1970s
Percentage of Total Tornadoes 1950-2012 (1285 total) within
1-4 km of Different 2010 Population Density
Classes (People/km2)
Class
Class Range:
1 km
2 km
3 km
4 km
Class 2
238-847
39
51
60
67
Class 3
848-1,779
24
30
35
41
Class 4
1,780-3,309
10
13
16
19
Class 5
3,310-6,497
1
2
3
4
Class 6
6,498-13,879
0
0
0
1
-0.79
-0.79
-0.80
Correlation:
-0.80
An indirect relationship: higher
percentage of tornado touchdown points
in land area with lower populations
However, the spatial distribution close
to major cities towns suggest a population
bias…
Spatially different
patterns -> La Niña more
concentrated touchdown
locations
 In terms of climatology,
no year has a greater risk
for more tornadoes
Transition between
phases appears to
contribute to active and
less active tornado years
 Several land surface
 Meteorology & climatology
are very cartographically
intensive sciences
(forecasters constantly look
at & analyze maps)!
 Sadly, a gap between those that
know meteorology & the
benefits of geospatial analysis
is present
 Indiana tornado days have
not increased or decreased
through time
 Note that tornado days are not
the same as tornadoes!
 Any given day can have 1 – 20+
tornadoes
relationships may be occurring
 topography
 physiographic regions
 land use : 42 % & 64% touched
down within 1 km of forest &
urban land areas, respectively
 All tornadoes: 43% & 61%
touched down within 1 km of
forest and urban, respectively
 Supports land-surface
heterogeneity hypotheses:
 Boundaries of temperature,
dewpoints, CAPE, vertical
velocities , & surface roughness
when transitioning from one
land use to another
Thank you! - Questions?!?!
 Special thanks to Dr. David L. Arnold & Tim Samaras
for inspiration and devotion to novel, challenging
research seeking to unravel the unsolved mysteries of
severe weather & tornadoes
 NWS Indianapolis for continued support
 Dev Niyogi & the Indiana State Climate Office
Email: okellner@purdue.edu