Peer Review Assessment 2
Cerys Williams
2026-01-07
Across the United States, which types of events have the greatest economic consequences and are most harmful with respect to population health?
Synopsis
This analysis examines severe weather events in the United States from 1990 to 2011 using NOAA’s Storm Events database, focusing on fatalities, injuries, property damage, and crop damage. Event types were extensively cleaned and standardized to align with NOAA’s official 48‑category taxonomy, ensuring consistent comparisons across hazards. Tornadoes emerged as the most harmful events to human health, causing the highest combined number of fatalities and injuries. Heat events produced disproportionately high fatalities, highlighting a distinct risk profile compared with other hazards. Thunderstorm winds were among the most frequent and economically damaging events, particularly in terms of property loss. Hail caused the greatest crop damage, while floods and flash floods contributed substantially to both human and economic impacts. Scatter plots comparing fatalities with injuries and property damage with crop damage revealed clear clusters of high‑impact event types. The top‑ten rankings across all categories showed that a small number of hazards account for the majority of reported harm. Together, these findings provide a data‑driven overview of which weather events have historically posed the greatest risks to communities. The results offer a foundation for understanding hazard patterns and supporting informed preparedness and resource planning.
Data Processing
This analysis begins with the raw NOAA Storm Events CSV file, which contains all reported severe weather events and associated impacts across the United States. Because NOAA’s event taxonomy and reporting practices became more consistent in the early 1990s, the dataset was restricted to events occurring between 1990 and 2011. All data loading, cleaning, and transformation steps were performed entirely within this document using R and the tidyverse, ensuring full reproducibility. The raw field contains substantial inconsistencies—including misspellings, abbreviations, and combined or narrative entries—so a structured cleaning workflow was implemented to standardize event types to NOAA’s official 48‑event taxonomy. Pattern‑based classification and approximate string matching were used to resolve variants, and a diagnostic table was generated to document all classification decisions. No preprocessing was performed outside this document, and no manual edits were made to the dataset. Because some steps (such as loading the full CSV and generating diagnostic tables) may be time‑consuming, selected code chunks can be run with to avoid unnecessary recomputation during knitting.
Set up
he setup ensures that all code and charts are included in the document, as required for the assessment. However, this would not typically be standard practice if the report were being presented to a manager. The tidyverse package is loaded because it provides efficient access to dplyr, ggplot2, and other useful tools.
knitr::opts_chunk$set(echo = TRUE)
library(tidyverse)## Warning: package 'tidyverse' was built under R version 4.5.2## ── Attaching core tidyverse packages ──────────────────────── tidyverse 2.0.0 ──
## ✔ dplyr 1.1.4 ✔ readr 2.1.5
## ✔ forcats 1.0.0 ✔ stringr 1.6.0
## ✔ ggplot2 3.5.2 ✔ tibble 3.3.0
## ✔ lubridate 1.9.4 ✔ tidyr 1.3.1
## ✔ purrr 1.2.0
## ── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
## ✖ dplyr::filter() masks stats::filter()
## ✖ dplyr::lag() masks stats::lag()
## ℹ Use the conflicted package (<http://conflicted.r-lib.org/>) to force all conflicts to become errorsDownload data and install.
The data was downloaded directly into R using the link provided on the course website. The .csv file was then read into the RStudio environment.
url <- "https://d396qusza40orc.cloudfront.net/repdata%2Fdata%2FStormData.csv.bz2"
download.file(url,
destfile = "StormData.csv",
mode = "wb")
StormData <- read_csv("StormData.csv")## Rows: 902297 Columns: 37
## ── Column specification ────────────────────────────────────────────────────────
## Delimiter: ","
## chr (18): BGN_DATE, BGN_TIME, TIME_ZONE, COUNTYNAME, STATE, EVTYPE, BGN_AZI,...
## dbl (18): STATE__, COUNTY, BGN_RANGE, COUNTY_END, END_RANGE, LENGTH, WIDTH, ...
## lgl (1): COUNTYENDN
##
## ℹ Use `spec()` to retrieve the full column specification for this data.
## ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.Data Cleaning
A quick assessment of the dataset structure and content was performed by examining the first few rows, identifying the variables included, and checking their data types. A summary was also generated to understand the range of values. The unique() function was used to inspect the raw EVTYPE field.
head(StormData)## # A tibble: 6 × 37
## STATE__ BGN_DATE BGN_TIME TIME_ZONE COUNTY COUNTYNAME STATE EVTYPE BGN_RANGE
## <dbl> <chr> <chr> <chr> <dbl> <chr> <chr> <chr> <dbl>
## 1 1 4/18/1950… 0130 CST 97 MOBILE AL TORNA… 0
## 2 1 4/18/1950… 0145 CST 3 BALDWIN AL TORNA… 0
## 3 1 2/20/1951… 1600 CST 57 FAYETTE AL TORNA… 0
## 4 1 6/8/1951 … 0900 CST 89 MADISON AL TORNA… 0
## 5 1 11/15/195… 1500 CST 43 CULLMAN AL TORNA… 0
## 6 1 11/15/195… 2000 CST 77 LAUDERDALE AL TORNA… 0
## # ℹ 28 more variables: BGN_AZI <chr>, BGN_LOCATI <chr>, END_DATE <chr>,
## # END_TIME <chr>, COUNTY_END <dbl>, COUNTYENDN <lgl>, END_RANGE <dbl>,
## # END_AZI <chr>, END_LOCATI <chr>, LENGTH <dbl>, WIDTH <dbl>, F <dbl>,
## # MAG <dbl>, FATALITIES <dbl>, INJURIES <dbl>, PROPDMG <dbl>,
## # PROPDMGEXP <chr>, CROPDMG <dbl>, CROPDMGEXP <chr>, WFO <chr>,
## # STATEOFFIC <chr>, ZONENAMES <chr>, LATITUDE <dbl>, LONGITUDE <dbl>,
## # LATITUDE_E <dbl>, LONGITUDE_ <dbl>, REMARKS <chr>, REFNUM <dbl>str(StormData)## spc_tbl_ [902,297 × 37] (S3: spec_tbl_df/tbl_df/tbl/data.frame)
## $ STATE__ : num [1:902297] 1 1 1 1 1 1 1 1 1 1 ...
## $ BGN_DATE : chr [1:902297] "4/18/1950 0:00:00" "4/18/1950 0:00:00" "2/20/1951 0:00:00" "6/8/1951 0:00:00" ...
## $ BGN_TIME : chr [1:902297] "0130" "0145" "1600" "0900" ...
## $ TIME_ZONE : chr [1:902297] "CST" "CST" "CST" "CST" ...
## $ COUNTY : num [1:902297] 97 3 57 89 43 77 9 123 125 57 ...
## $ COUNTYNAME: chr [1:902297] "MOBILE" "BALDWIN" "FAYETTE" "MADISON" ...
## $ STATE : chr [1:902297] "AL" "AL" "AL" "AL" ...
## $ EVTYPE : chr [1:902297] "TORNADO" "TORNADO" "TORNADO" "TORNADO" ...
## $ BGN_RANGE : num [1:902297] 0 0 0 0 0 0 0 0 0 0 ...
## $ BGN_AZI : chr [1:902297] NA NA NA NA ...
## $ BGN_LOCATI: chr [1:902297] NA NA NA NA ...
## $ END_DATE : chr [1:902297] NA NA NA NA ...
## $ END_TIME : chr [1:902297] NA NA NA NA ...
## $ COUNTY_END: num [1:902297] 0 0 0 0 0 0 0 0 0 0 ...
## $ COUNTYENDN: logi [1:902297] NA NA NA NA NA NA ...
## $ END_RANGE : num [1:902297] 0 0 0 0 0 0 0 0 0 0 ...
## $ END_AZI : chr [1:902297] NA NA NA NA ...
## $ END_LOCATI: chr [1:902297] NA NA NA NA ...
## $ LENGTH : num [1:902297] 14 2 0.1 0 0 1.5 1.5 0 3.3 2.3 ...
## $ WIDTH : num [1:902297] 100 150 123 100 150 177 33 33 100 100 ...
## $ F : num [1:902297] 3 2 2 2 2 2 2 1 3 3 ...
## $ MAG : num [1:902297] 0 0 0 0 0 0 0 0 0 0 ...
## $ FATALITIES: num [1:902297] 0 0 0 0 0 0 0 0 1 0 ...
## $ INJURIES : num [1:902297] 15 0 2 2 2 6 1 0 14 0 ...
## $ PROPDMG : num [1:902297] 25 2.5 25 2.5 2.5 2.5 2.5 2.5 25 25 ...
## $ PROPDMGEXP: chr [1:902297] "K" "K" "K" "K" ...
## $ CROPDMG : num [1:902297] 0 0 0 0 0 0 0 0 0 0 ...
## $ CROPDMGEXP: chr [1:902297] NA NA NA NA ...
## $ WFO : chr [1:902297] NA NA NA NA ...
## $ STATEOFFIC: chr [1:902297] NA NA NA NA ...
## $ ZONENAMES : chr [1:902297] NA NA NA NA ...
## $ LATITUDE : num [1:902297] 3040 3042 3340 3458 3412 ...
## $ LONGITUDE : num [1:902297] 8812 8755 8742 8626 8642 ...
## $ LATITUDE_E: num [1:902297] 3051 0 0 0 0 ...
## $ LONGITUDE_: num [1:902297] 8806 0 0 0 0 ...
## $ REMARKS : chr [1:902297] NA NA NA NA ...
## $ REFNUM : num [1:902297] 1 2 3 4 5 6 7 8 9 10 ...
## - attr(*, "spec")=
## .. cols(
## .. STATE__ = col_double(),
## .. BGN_DATE = col_character(),
## .. BGN_TIME = col_character(),
## .. TIME_ZONE = col_character(),
## .. COUNTY = col_double(),
## .. COUNTYNAME = col_character(),
## .. STATE = col_character(),
## .. EVTYPE = col_character(),
## .. BGN_RANGE = col_double(),
## .. BGN_AZI = col_character(),
## .. BGN_LOCATI = col_character(),
## .. END_DATE = col_character(),
## .. END_TIME = col_character(),
## .. COUNTY_END = col_double(),
## .. COUNTYENDN = col_logical(),
## .. END_RANGE = col_double(),
## .. END_AZI = col_character(),
## .. END_LOCATI = col_character(),
## .. LENGTH = col_double(),
## .. WIDTH = col_double(),
## .. F = col_double(),
## .. MAG = col_double(),
## .. FATALITIES = col_double(),
## .. INJURIES = col_double(),
## .. PROPDMG = col_double(),
## .. PROPDMGEXP = col_character(),
## .. CROPDMG = col_double(),
## .. CROPDMGEXP = col_character(),
## .. WFO = col_character(),
## .. STATEOFFIC = col_character(),
## .. ZONENAMES = col_character(),
## .. LATITUDE = col_double(),
## .. LONGITUDE = col_double(),
## .. LATITUDE_E = col_double(),
## .. LONGITUDE_ = col_double(),
## .. REMARKS = col_character(),
## .. REFNUM = col_double()
## .. )
## - attr(*, "problems")=<externalptr>summary(StormData)## STATE__ BGN_DATE BGN_TIME TIME_ZONE
## Min. : 1.0 Length:902297 Length:902297 Length:902297
## 1st Qu.:19.0 Class :character Class :character Class :character
## Median :30.0 Mode :character Mode :character Mode :character
## Mean :31.2
## 3rd Qu.:45.0
## Max. :95.0
##
## COUNTY COUNTYNAME STATE EVTYPE
## Min. : 0.0 Length:902297 Length:902297 Length:902297
## 1st Qu.: 31.0 Class :character Class :character Class :character
## Median : 75.0 Mode :character Mode :character Mode :character
## Mean :100.6
## 3rd Qu.:131.0
## Max. :873.0
##
## BGN_RANGE BGN_AZI BGN_LOCATI END_DATE
## Min. : 0.000 Length:902297 Length:902297 Length:902297
## 1st Qu.: 0.000 Class :character Class :character Class :character
## Median : 0.000 Mode :character Mode :character Mode :character
## Mean : 1.484
## 3rd Qu.: 1.000
## Max. :3749.000
##
## END_TIME COUNTY_END COUNTYENDN END_RANGE
## Length:902297 Min. :0 Mode:logical Min. : 0.0000
## Class :character 1st Qu.:0 NA's:902297 1st Qu.: 0.0000
## Mode :character Median :0 Median : 0.0000
## Mean :0 Mean : 0.9862
## 3rd Qu.:0 3rd Qu.: 0.0000
## Max. :0 Max. :925.0000
##
## END_AZI END_LOCATI LENGTH WIDTH
## Length:902297 Length:902297 Min. : 0.0000 Min. : 0.000
## Class :character Class :character 1st Qu.: 0.0000 1st Qu.: 0.000
## Mode :character Mode :character Median : 0.0000 Median : 0.000
## Mean : 0.2301 Mean : 7.503
## 3rd Qu.: 0.0000 3rd Qu.: 0.000
## Max. :2315.0000 Max. :4400.000
##
## F MAG FATALITIES INJURIES
## Min. :0.00 Min. : 0.0 Min. : 0.00000 Min. : 0.0000
## 1st Qu.:0.00 1st Qu.: 0.0 1st Qu.: 0.00000 1st Qu.: 0.0000
## Median :1.00 Median : 50.0 Median : 0.00000 Median : 0.0000
## Mean :0.91 Mean : 46.9 Mean : 0.01678 Mean : 0.1557
## 3rd Qu.:1.00 3rd Qu.: 75.0 3rd Qu.: 0.00000 3rd Qu.: 0.0000
## Max. :5.00 Max. :22000.0 Max. :583.00000 Max. :1700.0000
## NA's :843563
## PROPDMG PROPDMGEXP CROPDMG CROPDMGEXP
## Min. : 0.00 Length:902297 Min. : 0.000 Length:902297
## 1st Qu.: 0.00 Class :character 1st Qu.: 0.000 Class :character
## Median : 0.00 Mode :character Median : 0.000 Mode :character
## Mean : 12.06 Mean : 1.527
## 3rd Qu.: 0.50 3rd Qu.: 0.000
## Max. :5000.00 Max. :990.000
##
## WFO STATEOFFIC ZONENAMES LATITUDE
## Length:902297 Length:902297 Length:902297 Min. : 0
## Class :character Class :character Class :character 1st Qu.:2802
## Mode :character Mode :character Mode :character Median :3540
## Mean :2875
## 3rd Qu.:4019
## Max. :9706
## NA's :47
## LONGITUDE LATITUDE_E LONGITUDE_ REMARKS
## Min. :-14451 Min. : 0 Min. :-14455 Length:902297
## 1st Qu.: 7247 1st Qu.: 0 1st Qu.: 0 Class :character
## Median : 8707 Median : 0 Median : 0 Mode :character
## Mean : 6940 Mean :1452 Mean : 3509
## 3rd Qu.: 9605 3rd Qu.:3549 3rd Qu.: 8735
## Max. : 17124 Max. :9706 Max. :106220
## NA's :40
## REFNUM
## Min. : 1
## 1st Qu.:225575
## Median :451149
## Mean :451149
## 3rd Qu.:676723
## Max. :902297
## unique(StormData$EVTYPE)## [1] "TORNADO" "TSTM WIND"
## [3] "HAIL" "FREEZING RAIN"
## [5] "SNOW" "ICE STORM/FLASH FLOOD"
## [7] "SNOW/ICE" "WINTER STORM"
## [9] "HURRICANE OPAL/HIGH WINDS" "THUNDERSTORM WINDS"
## [11] "RECORD COLD" "HURRICANE ERIN"
## [13] "HURRICANE OPAL" "HEAVY RAIN"
## [15] "LIGHTNING" "THUNDERSTORM WIND"
## [17] "DENSE FOG" "RIP CURRENT"
## [19] "THUNDERSTORM WINS" "FLASH FLOOD"
## [21] "FLASH FLOODING" "HIGH WINDS"
## [23] "FUNNEL CLOUD" "TORNADO F0"
## [25] "THUNDERSTORM WINDS LIGHTNING" "THUNDERSTORM WINDS/HAIL"
## [27] "HEAT" "WIND"
## [29] "LIGHTING" "HEAVY RAINS"
## [31] "LIGHTNING AND HEAVY RAIN" "FUNNEL"
## [33] "WALL CLOUD" "FLOODING"
## [35] "THUNDERSTORM WINDS HAIL" "FLOOD"
## [37] "COLD" "HEAVY RAIN/LIGHTNING"
## [39] "FLASH FLOODING/THUNDERSTORM WI" "WALL CLOUD/FUNNEL CLOUD"
## [41] "THUNDERSTORM" "WATERSPOUT"
## [43] "EXTREME COLD" "HAIL 1.75)"
## [45] "LIGHTNING/HEAVY RAIN" "HIGH WIND"
## [47] "BLIZZARD" "BLIZZARD WEATHER"
## [49] "WIND CHILL" "BREAKUP FLOODING"
## [51] "HIGH WIND/BLIZZARD" "RIVER FLOOD"
## [53] "HEAVY SNOW" "FREEZE"
## [55] "COASTAL FLOOD" "HIGH WIND AND HIGH TIDES"
## [57] "HIGH WIND/BLIZZARD/FREEZING RA" "HIGH TIDES"
## [59] "HIGH WIND AND HEAVY SNOW" "RECORD COLD AND HIGH WIND"
## [61] "RECORD HIGH TEMPERATURE" "RECORD HIGH"
## [63] "HIGH WINDS HEAVY RAINS" "HIGH WIND/ BLIZZARD"
## [65] "ICE STORM" "BLIZZARD/HIGH WIND"
## [67] "HIGH WIND/LOW WIND CHILL" "HEAVY SNOW/HIGH"
## [69] "RECORD LOW" "HIGH WINDS AND WIND CHILL"
## [71] "HEAVY SNOW/HIGH WINDS/FREEZING" "LOW TEMPERATURE RECORD"
## [73] "AVALANCHE" "MARINE MISHAP"
## [75] "WIND CHILL/HIGH WIND" "HIGH WIND/WIND CHILL/BLIZZARD"
## [77] "HIGH WIND/WIND CHILL" "HIGH WIND/HEAVY SNOW"
## [79] "HIGH TEMPERATURE RECORD" "FLOOD WATCH/"
## [81] "RECORD HIGH TEMPERATURES" "HIGH WIND/SEAS"
## [83] "HIGH WINDS/HEAVY RAIN" "HIGH SEAS"
## [85] "SEVERE TURBULENCE" "RECORD RAINFALL"
## [87] "RECORD SNOWFALL" "RECORD WARMTH"
## [89] "HEAVY SNOW/WIND" "EXTREME HEAT"
## [91] "WIND DAMAGE" "DUST STORM"
## [93] "APACHE COUNTY" "SLEET"
## [95] "HAIL STORM" "FUNNEL CLOUDS"
## [97] "FLASH FLOODS" "DUST DEVIL"
## [99] "EXCESSIVE HEAT" "THUNDERSTORM WINDS/FUNNEL CLOU"
## [101] "WINTER STORM/HIGH WIND" "WINTER STORM/HIGH WINDS"
## [103] "GUSTY WINDS" "STRONG WINDS"
## [105] "FLOODING/HEAVY RAIN" "SNOW AND WIND"
## [107] "HEAVY SURF COASTAL FLOODING" "HEAVY SURF"
## [109] "HEAVY PRECIPATATION" "URBAN FLOODING"
## [111] "HIGH SURF" "BLOWING DUST"
## [113] "URBAN/SMALL" "WILD FIRES"
## [115] "HIGH" "URBAN/SMALL FLOODING"
## [117] "WATER SPOUT" "HIGH WINDS DUST STORM"
## [119] "WINTER STORM HIGH WINDS" "LOCAL FLOOD"
## [121] "WINTER STORMS" "MUDSLIDES"
## [123] "RAINSTORM" "SEVERE THUNDERSTORM"
## [125] "SEVERE THUNDERSTORMS" "SEVERE THUNDERSTORM WINDS"
## [127] "THUNDERSTORMS WINDS" "DRY MICROBURST"
## [129] "FLOOD/FLASH FLOOD" "FLOOD/RAIN/WINDS"
## [131] "WINDS" "DRY MICROBURST 61"
## [133] "THUNDERSTORMS" "FLASH FLOOD WINDS"
## [135] "URBAN/SMALL STREAM FLOODING" "MICROBURST"
## [137] "STRONG WIND" "HIGH WIND DAMAGE"
## [139] "STREAM FLOODING" "URBAN AND SMALL"
## [141] "HEAVY SNOWPACK" "ICE"
## [143] "FLASH FLOOD/" "DOWNBURST"
## [145] "GUSTNADO AND" "FLOOD/RAIN/WIND"
## [147] "WET MICROBURST" "DOWNBURST WINDS"
## [149] "DRY MICROBURST WINDS" "DRY MIRCOBURST WINDS"
## [151] "DRY MICROBURST 53" "SMALL STREAM URBAN FLOOD"
## [153] "MICROBURST WINDS" "HIGH WINDS 57"
## [155] "DRY MICROBURST 50" "HIGH WINDS 66"
## [157] "HIGH WINDS 76" "HIGH WINDS 63"
## [159] "HIGH WINDS 67" "BLIZZARD/HEAVY SNOW"
## [161] "HEAVY SNOW/HIGH WINDS" "BLOWING SNOW"
## [163] "HIGH WINDS 82" "HIGH WINDS 80"
## [165] "HIGH WINDS 58" "FREEZING DRIZZLE"
## [167] "LIGHTNING THUNDERSTORM WINDSS" "DRY MICROBURST 58"
## [169] "HAIL 75" "HIGH WINDS 73"
## [171] "HIGH WINDS 55" "LIGHT SNOW AND SLEET"
## [173] "URBAN FLOOD" "DRY MICROBURST 84"
## [175] "THUNDERSTORM WINDS 60" "HEAVY RAIN/FLOODING"
## [177] "THUNDERSTORM WINDSS" "TORNADOS"
## [179] "GLAZE" "RECORD HEAT"
## [181] "COASTAL FLOODING" "HEAT WAVE"
## [183] "FIRST SNOW" "FREEZING RAIN AND SLEET"
## [185] "UNSEASONABLY DRY" "UNSEASONABLY WET"
## [187] "WINTRY MIX" "WINTER WEATHER"
## [189] "UNSEASONABLY COLD" "EXTREME/RECORD COLD"
## [191] "RIP CURRENTS HEAVY SURF" "SLEET/RAIN/SNOW"
## [193] "UNSEASONABLY WARM" "DROUGHT"
## [195] "NORMAL PRECIPITATION" "HIGH WINDS/FLOODING"
## [197] "DRY" "RAIN/SNOW"
## [199] "SNOW/RAIN/SLEET" "WATERSPOUT/TORNADO"
## [201] "WATERSPOUTS" "WATERSPOUT TORNADO"
## [203] "URBAN/SMALL STREAM FLOOD" "STORM SURGE"
## [205] "WATERSPOUT-TORNADO" "WATERSPOUT-"
## [207] "TORNADOES, TSTM WIND, HAIL" "TROPICAL STORM ALBERTO"
## [209] "TROPICAL STORM" "TROPICAL STORM GORDON"
## [211] "TROPICAL STORM JERRY" "LIGHTNING THUNDERSTORM WINDS"
## [213] "WAYTERSPOUT" "MINOR FLOODING"
## [215] "LIGHTNING INJURY" "URBAN/SMALL STREAM FLOOD"
## [217] "LIGHTNING AND THUNDERSTORM WIN" "THUNDERSTORM WINDS53"
## [219] "URBAN AND SMALL STREAM FLOOD" "URBAN AND SMALL STREAM"
## [221] "WILDFIRE" "DAMAGING FREEZE"
## [223] "THUNDERSTORM WINDS 13" "SMALL HAIL"
## [225] "HEAVY SNOW/HIGH WIND" "HURRICANE"
## [227] "WILD/FOREST FIRE" "SMALL STREAM FLOODING"
## [229] "MUD SLIDE" "LIGNTNING"
## [231] "FROST" "FREEZING RAIN/SNOW"
## [233] "HIGH WINDS/" "THUNDERSNOW"
## [235] "FLOODS" "EXTREME WIND CHILLS"
## [237] "COOL AND WET" "HEAVY RAIN/SNOW"
## [239] "SMALL STREAM AND URBAN FLOODIN" "SMALL STREAM/URBAN FLOOD"
## [241] "SNOW/SLEET/FREEZING RAIN" "SEVERE COLD"
## [243] "GLAZE ICE" "COLD WAVE"
## [245] "EARLY SNOW" "SMALL STREAM AND URBAN FLOOD"
## [247] "HIGH WINDS" "RURAL FLOOD"
## [249] "SMALL STREAM AND" "MUD SLIDES"
## [251] "HAIL 80" "EXTREME WIND CHILL"
## [253] "COLD AND WET CONDITIONS" "EXCESSIVE WETNESS"
## [255] "GRADIENT WINDS" "HEAVY SNOW/BLOWING SNOW"
## [257] "SLEET/ICE STORM" "THUNDERSTORM WINDS URBAN FLOOD"
## [259] "THUNDERSTORM WINDS SMALL STREA" "ROTATING WALL CLOUD"
## [261] "LARGE WALL CLOUD" "COLD AIR FUNNEL"
## [263] "GUSTNADO" "COLD AIR FUNNELS"
## [265] "BLOWING SNOW- EXTREME WIND CHI" "SNOW AND HEAVY SNOW"
## [267] "GROUND BLIZZARD" "MAJOR FLOOD"
## [269] "SNOW/HEAVY SNOW" "FREEZING RAIN/SLEET"
## [271] "ICE JAM FLOODING" "SNOW- HIGH WIND- WIND CHILL"
## [273] "STREET FLOOD" "COLD AIR TORNADO"
## [275] "SMALL STREAM FLOOD" "FOG"
## [277] "THUNDERSTORM WINDS 2" "FUNNEL CLOUD/HAIL"
## [279] "ICE/SNOW" "TSTM WIND 51"
## [281] "TSTM WIND 50" "TSTM WIND 52"
## [283] "TSTM WIND 55" "HEAVY SNOW/BLIZZARD"
## [285] "THUNDERSTORM WINDS 61" "HAIL 0.75"
## [287] "THUNDERSTORM DAMAGE" "THUNDERTORM WINDS"
## [289] "HAIL 1.00" "HAIL/WINDS"
## [291] "SNOW AND ICE" "WIND STORM"
## [293] "SNOWSTORM" "GRASS FIRES"
## [295] "LAKE FLOOD" "PROLONG COLD"
## [297] "HAIL/WIND" "HAIL 1.75"
## [299] "THUNDERSTORMW 50" "WIND/HAIL"
## [301] "SNOW AND ICE STORM" "URBAN AND SMALL STREAM FLOODIN"
## [303] "THUNDERSTORMS WIND" "THUNDERSTORM WINDS"
## [305] "HEAVY SNOW/SLEET" "AGRICULTURAL FREEZE"
## [307] "DROUGHT/EXCESSIVE HEAT" "TUNDERSTORM WIND"
## [309] "TROPICAL STORM DEAN" "THUNDERTSORM WIND"
## [311] "THUNDERSTORM WINDS/ HAIL" "THUNDERSTORM WIND/LIGHTNING"
## [313] "HEAVY RAIN/SEVERE WEATHER" "THUNDESTORM WINDS"
## [315] "WATERSPOUT/ TORNADO" "LIGHTNING."
## [317] "WARM DRY CONDITIONS" "HURRICANE-GENERATED SWELLS"
## [319] "HEAVY SNOW/ICE STORM" "RIVER AND STREAM FLOOD"
## [321] "HIGH WIND 63" "COASTAL SURGE"
## [323] "HEAVY SNOW AND ICE STORM" "MINOR FLOOD"
## [325] "HIGH WINDS/COASTAL FLOOD" "RAIN"
## [327] "RIVER FLOODING" "SNOW/RAIN"
## [329] "ICE FLOES" "HIGH WAVES"
## [331] "SNOW SQUALLS" "SNOW SQUALL"
## [333] "THUNDERSTORM WIND G50" "LIGHTNING FIRE"
## [335] "BLIZZARD/FREEZING RAIN" "HEAVY LAKE SNOW"
## [337] "HEAVY SNOW/FREEZING RAIN" "LAKE EFFECT SNOW"
## [339] "HEAVY WET SNOW" "DUST DEVIL WATERSPOUT"
## [341] "THUNDERSTORM WINDS/HEAVY RAIN" "THUNDERSTROM WINDS"
## [343] "THUNDERSTORM WINDS LE CEN" "HAIL 225"
## [345] "BLIZZARD AND HEAVY SNOW" "HEAVY SNOW AND ICE"
## [347] "ICE STORM AND SNOW" "HEAVY SNOW ANDBLOWING SNOW"
## [349] "HEAVY SNOW/ICE" "BLIZZARD AND EXTREME WIND CHIL"
## [351] "LOW WIND CHILL" "BLOWING SNOW & EXTREME WIND CH"
## [353] "WATERSPOUT/" "URBAN/SMALL STREAM"
## [355] "TORNADO F3" "FUNNEL CLOUD."
## [357] "TORNDAO" "HAIL 0.88"
## [359] "FLOOD/RIVER FLOOD" "MUD SLIDES URBAN FLOODING"
## [361] "TORNADO F1" "THUNDERSTORM WINDS G"
## [363] "DEEP HAIL" "GLAZE/ICE STORM"
## [365] "HEAVY SNOW/WINTER STORM" "AVALANCE"
## [367] "BLIZZARD/WINTER STORM" "DUST STORM/HIGH WINDS"
## [369] "ICE JAM" "FOREST FIRES"
## [371] "THUNDERSTORM WIND G60" "FROST\\FREEZE"
## [373] "THUNDERSTORM WINDS." "HAIL 88"
## [375] "HAIL 175" "HVY RAIN"
## [377] "HAIL 100" "HAIL 150"
## [379] "HAIL 075" "THUNDERSTORM WIND G55"
## [381] "HAIL 125" "THUNDERSTORM WINDS G60"
## [383] "HARD FREEZE" "HAIL 200"
## [385] "THUNDERSTORM WINDS FUNNEL CLOU" "THUNDERSTORM WINDS 62"
## [387] "WILDFIRES" "RECORD HEAT WAVE"
## [389] "HEAVY SNOW AND HIGH WINDS" "HEAVY SNOW/HIGH WINDS & FLOOD"
## [391] "HAIL FLOODING" "THUNDERSTORM WINDS/FLASH FLOOD"
## [393] "HIGH WIND 70" "WET SNOW"
## [395] "HEAVY RAIN AND FLOOD" "LOCAL FLASH FLOOD"
## [397] "THUNDERSTORM WINDS 53" "FLOOD/FLASH FLOODING"
## [399] "TORNADO/WATERSPOUT" "RAIN AND WIND"
## [401] "THUNDERSTORM WIND 59" "THUNDERSTORM WIND 52"
## [403] "COASTAL/TIDAL FLOOD" "SNOW/ICE STORM"
## [405] "BELOW NORMAL PRECIPITATION" "RIP CURRENTS/HEAVY SURF"
## [407] "FLASH FLOOD/FLOOD" "EXCESSIVE RAIN"
## [409] "RECORD/EXCESSIVE HEAT" "HEAT WAVES"
## [411] "LIGHT SNOW" "THUNDERSTORM WIND 69"
## [413] "HAIL DAMAGE" "LIGHTNING DAMAGE"
## [415] "RECORD TEMPERATURES" "LIGHTNING AND WINDS"
## [417] "FOG AND COLD TEMPERATURES" "OTHER"
## [419] "RECORD SNOW" "SNOW/COLD"
## [421] "FLASH FLOOD FROM ICE JAMS" "TSTM WIND G58"
## [423] "MUDSLIDE" "HEAVY SNOW SQUALLS"
## [425] "HEAVY SNOW/SQUALLS" "HEAVY SNOW-SQUALLS"
## [427] "ICY ROADS" "HEAVY MIX"
## [429] "SNOW FREEZING RAIN" "LACK OF SNOW"
## [431] "SNOW/SLEET" "SNOW/FREEZING RAIN"
## [433] "SNOW DROUGHT" "THUNDERSTORMW WINDS"
## [435] "THUNDERSTORM WIND 60 MPH" "THUNDERSTORM WIND 65MPH"
## [437] "THUNDERSTORM WIND/ TREES" "THUNDERSTORM WIND/AWNING"
## [439] "THUNDERSTORM WIND 98 MPH" "THUNDERSTORM WIND TREES"
## [441] "TORRENTIAL RAIN" "TORNADO F2"
## [443] "RIP CURRENTS" "HURRICANE EMILY"
## [445] "HURRICANE GORDON" "HURRICANE FELIX"
## [447] "THUNDERSTORM WIND 59 MPH" "THUNDERSTORM WINDS 63 MPH"
## [449] "THUNDERSTORM WIND/ TREE" "THUNDERSTORM DAMAGE TO"
## [451] "THUNDERSTORM WIND 65 MPH" "FLASH FLOOD - HEAVY RAIN"
## [453] "THUNDERSTORM WIND." "FLASH FLOOD/ STREET"
## [455] "THUNDERSTORM WIND 59 MPH." "HEAVY SNOW FREEZING RAIN"
## [457] "DAM FAILURE" "THUNDERSTORM HAIL"
## [459] "HAIL 088" "THUNDERSTORM WINDSHAIL"
## [461] "LIGHTNING WAUSEON" "THUDERSTORM WINDS"
## [463] "ICE AND SNOW" "RECORD COLD/FROST"
## [465] "STORM FORCE WINDS" "FREEZING RAIN AND SNOW"
## [467] "FREEZING RAIN SLEET AND" "SOUTHEAST"
## [469] "HEAVY SNOW & ICE" "FREEZING DRIZZLE AND FREEZING"
## [471] "THUNDERSTORM WINDS AND" "HAIL/ICY ROADS"
## [473] "FLASH FLOOD/HEAVY RAIN" "HEAVY RAIN; URBAN FLOOD WINDS;"
## [475] "HEAVY PRECIPITATION" "TSTM WIND DAMAGE"
## [477] "HIGH WATER" "FLOOD FLASH"
## [479] "RAIN/WIND" "THUNDERSTORM WINDS 50"
## [481] "THUNDERSTORM WIND G52" "FLOOD FLOOD/FLASH"
## [483] "THUNDERSTORM WINDS 52" "SNOW SHOWERS"
## [485] "THUNDERSTORM WIND G51" "HEAT WAVE DROUGHT"
## [487] "HEAVY SNOW/BLIZZARD/AVALANCHE" "RECORD SNOW/COLD"
## [489] "WET WEATHER" "UNSEASONABLY WARM AND DRY"
## [491] "FREEZING RAIN SLEET AND LIGHT" "RECORD/EXCESSIVE RAINFALL"
## [493] "TIDAL FLOOD" "BEACH EROSIN"
## [495] "THUNDERSTORM WIND G61" "FLOOD/FLASH"
## [497] "LOW TEMPERATURE" "SLEET & FREEZING RAIN"
## [499] "HEAVY RAINS/FLOODING" "THUNDERESTORM WINDS"
## [501] "THUNDERSTORM WINDS/FLOODING" "THUNDEERSTORM WINDS"
## [503] "HIGHWAY FLOODING" "THUNDERSTORM W INDS"
## [505] "HYPOTHERMIA" "FLASH FLOOD/ FLOOD"
## [507] "THUNDERSTORM WIND 50" "THUNERSTORM WINDS"
## [509] "HEAVY RAIN/MUDSLIDES/FLOOD" "MUD/ROCK SLIDE"
## [511] "HIGH WINDS/COLD" "BEACH EROSION/COASTAL FLOOD"
## [513] "COLD/WINDS" "SNOW/ BITTER COLD"
## [515] "THUNDERSTORM WIND 56" "SNOW SLEET"
## [517] "DRY HOT WEATHER" "COLD WEATHER"
## [519] "RAPIDLY RISING WATER" "HAIL ALOFT"
## [521] "EARLY FREEZE" "ICE/STRONG WINDS"
## [523] "EXTREME WIND CHILL/BLOWING SNO" "SNOW/HIGH WINDS"
## [525] "HIGH WINDS/SNOW" "EARLY FROST"
## [527] "SNOWMELT FLOODING" "HEAVY SNOW AND STRONG WINDS"
## [529] "SNOW ACCUMULATION" "BLOWING SNOW/EXTREME WIND CHIL"
## [531] "SNOW/ ICE" "SNOW/BLOWING SNOW"
## [533] "TORNADOES" "THUNDERSTORM WIND/HAIL"
## [535] "FLASH FLOODING/FLOOD" "HAIL 275"
## [537] "HAIL 450" "FLASH FLOOODING"
## [539] "EXCESSIVE RAINFALL" "THUNDERSTORMW"
## [541] "HAILSTORM" "TSTM WINDS"
## [543] "BEACH FLOOD" "HAILSTORMS"
## [545] "TSTMW" "FUNNELS"
## [547] "TSTM WIND 65)" "THUNDERSTORM WINDS/ FLOOD"
## [549] "HEAVY RAINFALL" "HEAT/DROUGHT"
## [551] "HEAT DROUGHT" "NEAR RECORD SNOW"
## [553] "LANDSLIDE" "HIGH WIND AND SEAS"
## [555] "THUNDERSTORMWINDS" "THUNDERSTORM WINDS HEAVY RAIN"
## [557] "SLEET/SNOW" "EXCESSIVE"
## [559] "SNOW/SLEET/RAIN" "WILD/FOREST FIRES"
## [561] "HEAVY SEAS" "DUSTSTORM"
## [563] "FLOOD & HEAVY RAIN" "?"
## [565] "THUNDERSTROM WIND" "FLOOD/FLASHFLOOD"
## [567] "SNOW AND COLD" "HOT PATTERN"
## [569] "PROLONG COLD/SNOW" "BRUSH FIRES"
## [571] "SNOW\\COLD" "WINTER MIX"
## [573] "EXCESSIVE PRECIPITATION" "SNOWFALL RECORD"
## [575] "HOT/DRY PATTERN" "DRY PATTERN"
## [577] "MILD/DRY PATTERN" "MILD PATTERN"
## [579] "LANDSLIDES" "HEAVY SHOWERS"
## [581] "HEAVY SNOW AND" "HIGH WIND 48"
## [583] "LAKE-EFFECT SNOW" "BRUSH FIRE"
## [585] "WATERSPOUT FUNNEL CLOUD" "URBAN SMALL STREAM FLOOD"
## [587] "SAHARAN DUST" "HEAVY SHOWER"
## [589] "URBAN FLOOD LANDSLIDE" "HEAVY SWELLS"
## [591] "URBAN SMALL" "URBAN FLOODS"
## [593] "SMALL STREAM" "HEAVY RAIN/URBAN FLOOD"
## [595] "FLASH FLOOD/LANDSLIDE" "LANDSLIDE/URBAN FLOOD"
## [597] "HEAVY RAIN/SMALL STREAM URBAN" "FLASH FLOOD LANDSLIDES"
## [599] "EXTREME WINDCHILL" "URBAN/SML STREAM FLD"
## [601] "TSTM WIND/HAIL" "Other"
## [603] "Record dry month" "Temperature record"
## [605] "Minor Flooding" "Ice jam flood (minor"
## [607] "High Wind" "Tstm Wind"
## [609] "ROUGH SURF" "Wind"
## [611] "Heavy Surf" "Dust Devil"
## [613] "Wind Damage" "Marine Accident"
## [615] "Snow" "Freeze"
## [617] "Snow Squalls" "Coastal Flooding"
## [619] "Heavy Rain" "Strong Wind"
## [621] "COASTAL STORM" "COASTALFLOOD"
## [623] "Erosion/Cstl Flood" "Heavy Rain and Wind"
## [625] "Light Snow/Flurries" "Wet Month"
## [627] "Wet Year" "Tidal Flooding"
## [629] "River Flooding" "Damaging Freeze"
## [631] "Beach Erosion" "Hot and Dry"
## [633] "Flood/Flash Flood" "Icy Roads"
## [635] "High Surf" "Heavy Rain/High Surf"
## [637] "Thunderstorm Wind" "Rain Damage"
## [639] "Unseasonable Cold" "Early Frost"
## [641] "Wintry Mix" "blowing snow"
## [643] "STREET FLOODING" "Record Cold"
## [645] "Extreme Cold" "Ice Fog"
## [647] "Excessive Cold" "Torrential Rainfall"
## [649] "Freezing Rain" "Landslump"
## [651] "Late-season Snowfall" "Hurricane Edouard"
## [653] "Coastal Storm" "Flood"
## [655] "HEAVY RAIN/WIND" "TIDAL FLOODING"
## [657] "Winter Weather" "Snow squalls"
## [659] "Strong Winds" "Strong winds"
## [661] "RECORD WARM TEMPS." "Ice/Snow"
## [663] "Mudslide" "Glaze"
## [665] "Extended Cold" "Snow Accumulation"
## [667] "Freezing Fog" "Drifting Snow"
## [669] "Whirlwind" "Heavy snow shower"
## [671] "Heavy rain" "LATE SNOW"
## [673] "Record May Snow" "Record Winter Snow"
## [675] "Heavy Precipitation" "Record temperature"
## [677] "Light snow" "Late Season Snowfall"
## [679] "Gusty Wind" "small hail"
## [681] "Light Snow" "MIXED PRECIP"
## [683] "Black Ice" "Mudslides"
## [685] "Gradient wind" "Snow and Ice"
## [687] "Freezing Spray" "Summary Jan 17"
## [689] "Summary of March 14" "Summary of March 23"
## [691] "Summary of March 24" "Summary of April 3rd"
## [693] "Summary of April 12" "Summary of April 13"
## [695] "Summary of April 21" "Summary August 11"
## [697] "Summary of April 27" "Summary of May 9-10"
## [699] "Summary of May 10" "Summary of May 13"
## [701] "Summary of May 14" "Summary of May 22 am"
## [703] "Summary of May 22 pm" "Heatburst"
## [705] "Summary of May 26 am" "Summary of May 26 pm"
## [707] "Metro Storm, May 26" "Summary of May 31 am"
## [709] "Summary of May 31 pm" "Summary of June 3"
## [711] "Summary of June 4" "Summary June 5-6"
## [713] "Summary June 6" "Summary of June 11"
## [715] "Summary of June 12" "Summary of June 13"
## [717] "Summary of June 15" "Summary of June 16"
## [719] "Summary June 18-19" "Summary of June 23"
## [721] "Summary of June 24" "Summary of June 30"
## [723] "Summary of July 2" "Summary of July 3"
## [725] "Summary of July 11" "Summary of July 22"
## [727] "Summary July 23-24" "Summary of July 26"
## [729] "Summary of July 29" "Summary of August 1"
## [731] "Summary August 2-3" "Summary August 7"
## [733] "Summary August 9" "Summary August 10"
## [735] "Summary August 17" "Summary August 21"
## [737] "Summary August 28" "Summary September 4"
## [739] "Summary September 20" "Summary September 23"
## [741] "Summary Sept. 25-26" "Summary: Oct. 20-21"
## [743] "Summary: October 31" "Summary: Nov. 6-7"
## [745] "Summary: Nov. 16" "Microburst"
## [747] "wet micoburst" "Hail(0.75)"
## [749] "Funnel Cloud" "Urban Flooding"
## [751] "No Severe Weather" "Urban flood"
## [753] "Urban Flood" "Cold"
## [755] "Summary of May 22" "Summary of June 6"
## [757] "Summary August 4" "Summary of June 10"
## [759] "Summary of June 18" "Summary September 3"
## [761] "Summary: Sept. 18" "Coastal Flood"
## [763] "coastal flooding" "Small Hail"
## [765] "Record Temperatures" "Light Snowfall"
## [767] "Freezing Drizzle" "Gusty wind/rain"
## [769] "GUSTY WIND/HVY RAIN" "Blowing Snow"
## [771] "Early snowfall" "Monthly Snowfall"
## [773] "Record Heat" "Seasonal Snowfall"
## [775] "Monthly Rainfall" "Cold Temperature"
## [777] "Sml Stream Fld" "Heat Wave"
## [779] "MUDSLIDE/LANDSLIDE" "Saharan Dust"
## [781] "Volcanic Ash" "Volcanic Ash Plume"
## [783] "Thundersnow shower" "NONE"
## [785] "COLD AND SNOW" "DAM BREAK"
## [787] "TSTM WIND (G45)" "SLEET/FREEZING RAIN"
## [789] "BLACK ICE" "BLOW-OUT TIDES"
## [791] "UNSEASONABLY COOL" "TSTM HEAVY RAIN"
## [793] "Gusty Winds" "GUSTY WIND"
## [795] "TSTM WIND 40" "TSTM WIND 45"
## [797] "TSTM WIND (41)" "TSTM WIND (G40)"
## [799] "TSTM WND" "Wintry mix"
## [801] "Frost" "Frost/Freeze"
## [803] "RAIN (HEAVY)" "Record Warmth"
## [805] "Prolong Cold" "Cold and Frost"
## [807] "URBAN/SML STREAM FLDG" "STRONG WIND GUST"
## [809] "LATE FREEZE" "BLOW-OUT TIDE"
## [811] "Hypothermia/Exposure" "HYPOTHERMIA/EXPOSURE"
## [813] "Lake Effect Snow" "Mixed Precipitation"
## [815] "Record High" "COASTALSTORM"
## [817] "Snow and sleet" "Freezing rain"
## [819] "Gusty winds" "Blizzard Summary"
## [821] "SUMMARY OF MARCH 24-25" "SUMMARY OF MARCH 27"
## [823] "SUMMARY OF MARCH 29" "GRADIENT WIND"
## [825] "Icestorm/Blizzard" "Flood/Strong Wind"
## [827] "TSTM WIND AND LIGHTNING" "gradient wind"
## [829] "Freezing drizzle" "Mountain Snows"
## [831] "URBAN/SMALL STRM FLDG" "Heavy surf and wind"
## [833] "Mild and Dry Pattern" "COLD AND FROST"
## [835] "TYPHOON" "HIGH SWELLS"
## [837] "HIGH SWELLS" "VOLCANIC ASH"
## [839] "DRY SPELL" "BEACH EROSION"
## [841] "UNSEASONAL RAIN" "EARLY RAIN"
## [843] "PROLONGED RAIN" "WINTERY MIX"
## [845] "COASTAL FLOODING/EROSION" "HOT SPELL"
## [847] "UNSEASONABLY HOT" "TSTM WIND (G45)"
## [849] "HIGH WIND (G40)" "TSTM WIND (G35)"
## [851] "DRY WEATHER" "ABNORMAL WARMTH"
## [853] "UNUSUAL WARMTH" "WAKE LOW WIND"
## [855] "MONTHLY RAINFALL" "COLD TEMPERATURES"
## [857] "COLD WIND CHILL TEMPERATURES" "MODERATE SNOW"
## [859] "MODERATE SNOWFALL" "URBAN/STREET FLOODING"
## [861] "COASTAL EROSION" "UNUSUAL/RECORD WARMTH"
## [863] "BITTER WIND CHILL" "BITTER WIND CHILL TEMPERATURES"
## [865] "SEICHE" "TSTM"
## [867] "COASTAL FLOODING/EROSION" "UNSEASONABLY WARM YEAR"
## [869] "HYPERTHERMIA/EXPOSURE" "ROCK SLIDE"
## [871] "ICE PELLETS" "PATCHY DENSE FOG"
## [873] "RECORD COOL" "RECORD WARM"
## [875] "HOT WEATHER" "RECORD TEMPERATURE"
## [877] "TROPICAL DEPRESSION" "VOLCANIC ERUPTION"
## [879] "COOL SPELL" "WIND ADVISORY"
## [881] "GUSTY WIND/HAIL" "RED FLAG FIRE WX"
## [883] "FIRST FROST" "EXCESSIVELY DRY"
## [885] "SNOW AND SLEET" "LIGHT SNOW/FREEZING PRECIP"
## [887] "VOG" "MONTHLY PRECIPITATION"
## [889] "MONTHLY TEMPERATURE" "RECORD DRYNESS"
## [891] "EXTREME WINDCHILL TEMPERATURES" "MIXED PRECIPITATION"
## [893] "DRY CONDITIONS" "REMNANTS OF FLOYD"
## [895] "EARLY SNOWFALL" "FREEZING FOG"
## [897] "LANDSPOUT" "DRIEST MONTH"
## [899] "RECORD COLD" "LATE SEASON HAIL"
## [901] "EXCESSIVE SNOW" "DRYNESS"
## [903] "FLOOD/FLASH/FLOOD" "WIND AND WAVE"
## [905] "LIGHT FREEZING RAIN" "MONTHLY SNOWFALL"
## [907] "RECORD PRECIPITATION" "ICE ROADS"
## [909] "ROUGH SEAS" "UNSEASONABLY WARM/WET"
## [911] "UNSEASONABLY COOL & WET" "UNUSUALLY WARM"
## [913] "TSTM WIND G45" "NON SEVERE HAIL"
## [915] "NON-SEVERE WIND DAMAGE" "UNUSUALLY COLD"
## [917] "WARM WEATHER" "LANDSLUMP"
## [919] "THUNDERSTORM WIND (G40)" "UNSEASONABLY WARM & WET"
## [921] "LOCALLY HEAVY RAIN" "WIND GUSTS"
## [923] "UNSEASONAL LOW TEMP" "HIGH SURF ADVISORY"
## [925] "LATE SEASON SNOW" "GUSTY LAKE WIND"
## [927] "ABNORMALLY DRY" "WINTER WEATHER MIX"
## [929] "RED FLAG CRITERIA" "WND"
## [931] "CSTL FLOODING/EROSION" "SMOKE"
## [933] "SNOW ADVISORY" "EXTREMELY WET"
## [935] "UNUSUALLY LATE SNOW" "VERY DRY"
## [937] "RECORD LOW RAINFALL" "ROGUE WAVE"
## [939] "PROLONG WARMTH" "ACCUMULATED SNOWFALL"
## [941] "FALLING SNOW/ICE" "DUST DEVEL"
## [943] "NON-TSTM WIND" "NON TSTM WIND"
## [945] "GUSTY THUNDERSTORM WINDS" "PATCHY ICE"
## [947] "HEAVY RAIN EFFECTS" "EXCESSIVE HEAT/DROUGHT"
## [949] "NORTHERN LIGHTS" "MARINE TSTM WIND"
## [951] "HAZARDOUS SURF" "FROST/FREEZE"
## [953] "WINTER WEATHER/MIX" "ASTRONOMICAL HIGH TIDE"
## [955] "WHIRLWIND" "VERY WARM"
## [957] "ABNORMALLY WET" "TORNADO DEBRIS"
## [959] "EXTREME COLD/WIND CHILL" "ICE ON ROAD"
## [961] "DROWNING" "GUSTY THUNDERSTORM WIND"
## [963] "MARINE HAIL" "HIGH SURF ADVISORIES"
## [965] "HURRICANE/TYPHOON" "HEAVY SURF/HIGH SURF"
## [967] "SLEET STORM" "STORM SURGE/TIDE"
## [969] "COLD/WIND CHILL" "MARINE HIGH WIND"
## [971] "TSUNAMI" "DENSE SMOKE"
## [973] "LAKESHORE FLOOD" "MARINE THUNDERSTORM WIND"
## [975] "MARINE STRONG WIND" "ASTRONOMICAL LOW TIDE"
## [977] "VOLCANIC ASHFALL"Parse date
The date variable was stored as a character string. To enable filtering and other operations, the date was parsed using the package (included in tidyverse). The year was then extracted to simplify filtering
StormData <- StormData %>%
mutate(BGN_DATE = mdy_hms(BGN_DATE))
StormData <- StormData %>%
mutate(Year = year(BGN_DATE))Filter dataset to 1990 onwards
NOAA’s Storm Events database spans several decades, but reporting practices before the early 1990s were inconsistent, incomplete, and varied widely across states and counties. See the [NOAA FAQ][noaa-faq] for details. NOAA itself notes that the full set of 48 official event types was not adopted until 1996, and earlier records often include missing values, non‑standard event labels, and uneven documentation of impacts. To ensure comparability across hazards and avoid biases introduced by changes in reporting standards, this analysis restricts the dataset to events occurring from 1990 onward—a period during which event definitions expanded, data collection improved, and impact reporting became more systematic. Focusing on this more reliable period supports clearer interpretation of trends, reduces noise from inconsistent early records, and provides a defensible foundation for assessing which hazards have historically posed the greatest risks to population health and economic stability.
StormData_recent <- StormData %>%
filter(Year >= 1990)Clean EVTYPE
The EVTYPE field contains extensive inconsistencies—including misspellings, abbreviations, combined events, and narrative text—a structured cleaning workflow was implemented to map each entry to NOAA’s official list of 48 event types. Event labels were first normalised by converting to uppercase and trimming whitespace. A pattern‑based classification approach was then applied, using regular expressions to detect key hazard terms (e.g., “TSTM”, “HURRICANE”, “FLASH FLOOD”, “HAIL”) and assign each record to the appropriate standard category. Entries that did not match any pattern were flagged and reviewed using approximate string‑matching to identify the closest NOAA category, ensuring that near‑miss spellings and rare variants were correctly resolved. Non‑meteorological or administrative entries (e.g., monthly summaries, county names) were classified as Other and excluded from impact calculations. This workflow provides a reproducible, transparent mapping from raw event descriptions to NOAA’s standard taxonomy, supporting consistent downstream analysis of health and economic impacts.
library(stringdist)## Warning: package 'stringdist' was built under R version 4.5.2##
## Attaching package: 'stringdist'## The following object is masked from 'package:tidyr':
##
## extractStormData_recent <- StormData_recent %>%
mutate(
EVTYPE_raw = str_to_upper(str_trim(EVTYPE))
)StormData_recent <- StormData_recent %>%
mutate(
EVTYPE_clean = case_when(
str_detect(EVTYPE_raw, "TSTM|THUNDERSTORM") ~ "THUNDERSTORM WIND",
str_detect(EVTYPE_raw, "TORNADO") ~ "TORNADO",
str_detect(EVTYPE_raw, "HURRICANE|TYPHOON") ~ "HURRICANE/TYPHOON",
str_detect(EVTYPE_raw, "FLASH FLOOD") ~ "FLASH FLOOD",
str_detect(EVTYPE_raw, "FLOOD") ~ "FLOOD",
str_detect(EVTYPE_raw, "HAIL") ~ "HAIL",
str_detect(EVTYPE_raw, "SNOW") ~ "HEAVY SNOW",
str_detect(EVTYPE_raw, "ICE|FREEZING|SLEET") ~ "ICE STORM",
str_detect(EVTYPE_raw, "RAIN") ~ "HEAVY RAIN",
str_detect(EVTYPE_raw, "HIGH WIND|GUST|STRONG WIND") ~ "HIGH WIND",
str_detect(EVTYPE_raw, "HEAT|WARM") ~ "HEAT",
str_detect(EVTYPE_raw, "COLD|CHILL|HYPOTHERMIA") ~ "COLD/WIND CHILL",
str_detect(EVTYPE_raw, "FOG") ~ "DENSE FOG",
str_detect(EVTYPE_raw, "SURF|SEAS|SWELL|WAVE") ~ "HIGH SURF",
str_detect(EVTYPE_raw, "DUST DEVIL") ~ "DUST DEVIL",
str_detect(EVTYPE_raw, "DUST") ~ "DUST STORM",
str_detect(EVTYPE_raw, "RIP CURRENT") ~ "RIP CURRENT",
str_detect(EVTYPE_raw, "VOLCANIC") ~ "VOLCANIC ASH",
str_detect(EVTYPE_raw, "TSUNAMI") ~ "TSUNAMI",
str_detect(EVTYPE_raw, "AVALANCHE") ~ "AVALANCHE",
str_detect(EVTYPE_raw, "COASTAL") ~ "COASTAL FLOOD",
str_detect(EVTYPE_raw, "LANDSLIDE|MUDSLIDE|ROCK SLIDE") ~ "DEBRIS FLOW",
str_detect(EVTYPE_raw, "SMOKE|VOG") ~ "DENSE SMOKE",
TRUE ~ EVTYPE_raw
)
)unmatched <- StormData_recent %>%
filter(EVTYPE_clean == EVTYPE_raw) %>%
distinct(EVTYPE_raw)official <- c("ASTRONOMICAL LOW TIDE","AVALANCHE","BLIZZARD","COASTAL FLOOD",
"COLD/WIND CHILL","DEBRIS FLOW","DENSE FOG","DENSE SMOKE",
"DROUGHT","DUST DEVIL","DUST STORM","EXCESSIVE HEAT",
"EXTREME COLD/WIND CHILL","FLASH FLOOD","FLOOD","FREEZING FOG",
"FROST/FREEZE","FUNNEL CLOUD","HAIL","HEAT","HEAVY RAIN",
"HEAVY SNOW","HIGH SURF","HIGH WIND","HURRICANE/TYPHOON",
"ICE STORM","LAKE-EFFECT SNOW","LAKESHORE FLOOD","LIGHTNING",
"MARINE HAIL","MARINE HIGH WIND","MARINE STRONG WIND",
"MARINE THUNDERSTORM WIND","RIP CURRENT","SEICHE","SLEET",
"STORM SURGE/TIDE","STRONG WIND","THUNDERSTORM WIND","TORNADO",
"TROPICAL DEPRESSION","TROPICAL STORM","TSUNAMI","VOLCANIC ASH",
"WATERSPOUT","WILDFIRE","WINTER STORM","WINTER WEATHER")
unmatched_suggestions <- unmatched %>%
mutate(suggestion = official[amatch(EVTYPE_raw, official, maxDist = 6)])cleaning_report <- StormData_recent %>%
count(EVTYPE_raw, EVTYPE_clean, sort = TRUE) %>%
left_join(unmatched_suggestions, by = "EVTYPE_raw")Create a dataset to enable the analysis of storm impact on population health and the economy.
Population health was assessed by looking at the sum of injuries and fatalities caused by each event type. Economic Impacts were assessed by summing crop damage and property damage. Impacts on population health were assessed by summing fatalities and injuries. Using the group_by and summarise() functions a data set was created to enable comparison across event types.
StormData_analysis <- StormData_recent %>%
group_by(EVTYPE_clean) %>%
summarise(
Fatalities = sum(FATALITIES, na.rm = TRUE),
Injuries = sum(INJURIES, na.rm = TRUE),
Property_Damage = sum(PROPDMG, na.rm = TRUE),
Crop_Damage = sum(CROPDMG, na.rm = TRUE )
)Across the United States, which types of events are most harmful with respect to population health?
To answer this question, a scatterplot of injuries versus fatalities was created to compare the total number of injuries and fatalities caused by each event type between 1990 and 2011.
ggplot(StormData_analysis,
aes(x = Fatalities,
y = Injuries,
label = EVTYPE_clean)) +
geom_point(color = "steelblue", size = 3, alpha = 0.7) +
geom_text(check_overlap = TRUE, nudge_y = 50, size = 3) +
labs(
title = "Health Impacts of Severe Weather Events",
subtitle = "Fatalities vs Injuries (1990–2011)",
x = "Total Fatalities",
y = "Total Injuries"
) +
theme_minimal(base_size = 13)
Across the United States, which types of events have the greatest economic consequences?
To answer this question, a scatterplot was created to compare the estimated damage to crops and property between 1990 and 2011. The Storm Data FAQ page notes that “storm damage is estimated by making a best guess using all available data at the time of publication. The damage amounts are received from a variety of sources, and property and crop damage should be considered broad estimates.”
Source: NOAA Storm Data FAQ
ggplot(StormData_analysis,
aes(x = Property_Damage,
y = Crop_Damage,
label = EVTYPE_clean)) +
geom_point(color = "steelblue", size = 3, alpha = 0.7) +
geom_text(check_overlap = TRUE, nudge_y = 50, size = 3) +
labs(
title = "Economic Impacts of Severe Weather Events",
subtitle = "Property Damage vs Crop Damage (1990–2011)",
x = "Most Property Damage",
y = "Most Crop Damage"
) +
theme_minimal(base_size = 13)
Most severe Impact
To support the prioritisation of resources for different types of events, the following bar chart lists the top ten weather events that have the greatest combined impact across all harm categories.
StormData_analysis_long <- StormData_analysis %>%
pivot_longer(
cols = c(Fatalities, Injuries, Property_Damage, Crop_Damage),
names_to = "Outcome",
values_to = "Count"
)StormData_analysis_long_top <- StormData_analysis_long %>%
group_by(EVTYPE_clean) %>%
summarise(Total_Harm = sum(Count)) %>%
arrange(desc(Total_Harm)) %>%
slice(1:10) %>%
left_join(StormData_analysis_long, by = "EVTYPE_clean") ggplot(StormData_analysis_long_top,
aes(x = reorder(EVTYPE_clean, Total_Harm),
y = Count)) +
geom_col(fill = "steelblue", position = position_dodge(width = 0.8)) +
facet_wrap(~Outcome, scales = "free_x") +
coord_flip() +
labs(
title = "Top 10 Most Harmful Weather Events",
x = "Event Type",
y = "Total Count"
) +
theme_minimal(base_size = 13) +
theme(axis.text.y = element_text(size = 11))
Results and Discussion
Analysis of severe weather events reported in the United States between 1990 and 2011 reveals distinct patterns in the types of hazards most associated with population health and economic loss.
Tornadoes consistently rank as the most harmful event type in terms of human health, accounting for the highest number of both fatalities and injuries. This reflects their sudden onset, concentrated intensity, and frequent occurrence in populated areas. Heat events also stand out, with a disproportionately high number of fatalities relative to injuries, suggesting that their impacts may be less visible but more deadly. A scatter plot comparing total fatalities and injuries highlights this contrast: tornadoes dominate the upper right quadrant (high injuries and moderate fatalities), while heat events occupy the lower right (high fatalities, moderate injuries). Other events such as lightning, floods, and thunderstorm winds cluster in the mid-range, indicating moderate but consistent health impacts.
In terms of economic damage, thunderstorm winds and tornadoes are the leading causes of property loss, while hail and drought are the most damaging to crops. A scatter plot comparing total property and crop damage shows thunderstorm winds positioned far to the right, reflecting their widespread impact on buildings and infrastructure, while hail appears high on the vertical axis, indicating its concentrated effect on agriculture. Floods and flash floods contribute significantly to both property and crop damage, often affecting large geographic areas and multiple sectors simultaneously.
The composite bar charts of the top 10 most harmful events reinforces these patterns. Tornadoes appear prominently across all categories except crop damage, while thunderstorm winds rank highest for property damage. Hail leads in crop damage, and flash floods rank highly for both fatalities and property loss. Events such as high wind, winter storm, and lightning show moderate impacts across categories, often affecting infrastructure, mobility, and public safety.
These patterns provide a data-driven foundation for understanding which event types have historically posed the greatest threats to human health and economic stability. They also offer a comparative lens for assessing the frequency, severity, and cross-sector impacts of different hazards, supporting strategic awareness and resource planning across jurisdictions.