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Irma Only A Top 25 US Storm

September 12, 2017

By Paul Homewood

 

 

As Florida clears up after Hurricane Irma, how does it rank with other major US landfalling hurricanes?

When Irma made landfall on the Keys, it was estimated to have had sustained wind speeds of 115 kt , about 132 mph. (It actually hit the Florida coast as a Cat 3, with winds of 115 mph, but the Florida Keys count as the first landfall).

Since 1851, there have been 14 stronger hurricanes at landfall, and Irma ties with 10 others. In other words, Irma is one of 25 hurricanes as strong or stronger.

Year Name kt
1856 Last Island 130
1886 Indianola 130
1893 Chenier 115
1898 No Name 115
1900 Galveston 120
1915 Galveston 115
1916 No Name 115
1919 No Name 130
1926 Great Miami 125
1928 Okeechobee 125
1932 Freeport 130
1935 Labour Day 160
1945 No Name 115
1947 No Name 115
1948 No Name 115
1950 King 115
1954 Hazel 115
1959 Gracie 115
1960 Donna 125
1961 Carla 125
1969 Camille 155
1989 Hugo 120
1992 Andrew 145
2004 Charley 130
2016 Harvey 115
2016 Irma 115

https://web.archive.org/web/20170831001607/http://www.aoml.noaa.gov/hrd/hurdat/All_U.S._Hurricanes.html

 

 

Irma and Harvey have been the only two major hurricanes in the last ten years. The busiest decades were the 1940s and 1890s.

 

image

 

Calculating the number of hurricanes across the whole Atlantic basin is more problematic, because of the lack of aircraft and satellite observations in early years.

To address this, NOAA’s Atlantic Hurricane Database Re-analysis Project has attempted to reconstruct the numbers. The orange line reflects this:

 

cyclones-download1-2016

https://www.epa.gov/climate-indicators/climate-change-indicators-tropical-cyclone-activity

As far as we can see, there is no significant trend in the number of hurricanes. What we can quite clearly see is the influence of the AMO:

 

tsgcos.corr.81.159.104.33.254.7.22.5

https://www.esrl.noaa.gov/psd/cgi-bin/gcos_wgsp/tsanalysis.pl?tstype1=91&tstype2=0&year1=1880&year2=&itypea=0&axistype=0&anom=0&plotstyle=0&climo1=&climo2=&y1=&y2=&y21=&y22=&length=&lag=&iall=0&iseas=0&mon1=0&mon2=11&Submit=Calculate+Results

 

The latest news from Florida suggests damage is much less than originally feared, even on the Keys. In particular, the powerful storm surge never really emerged, and Tampa escaped relatively unscathed.

Ironically, the worst of the flooding seems to have occurred up in Jacksonville, as a result of rainfall.

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15 Comments
  1. September 12, 2017 2:11 pm

    Wasn’t landfall in the Virgin islands way before it got to Florida? What sort of strength was it there?

    • John Ellyssen permalink
      September 12, 2017 2:49 pm

      Virgin Islands are a protectorate of the U.S. but not part of mainland U.S. A wind gust of 131 mph was reported at Buck Island, and a gust of 87 mph was measured on St. Thomas Wednesday, Sept. 6. Heavy damage by the storm to the islands and a lot of looting. U.S. Navy aircraft carrier started delivering supplies the next morning (Sep 7).

  2. Jack Broughton permalink
    September 12, 2017 2:32 pm

    I can understand the first graph but not the second graph: how can a fraction of a hurricane occur? Surely they must be integers? Am I missing something?

    • John Ellyssen permalink
      September 12, 2017 2:41 pm

      I would hazard a guess that it is storms that dropped to Tropical Storm level.

    • John F. Hultquist permalink
      September 12, 2017 2:44 pm

      Am I missing something?

      The chart is from the US-EPA. Computer graphics/charts applications permit the production of continuous lines even when that data are discrete integer units.
      You will also see simple linear equations presented to about 16 decimal places with a “best fit” line.
      Those presenting such information are missing this: Just because something can be done, does not mean it should be done.

  3. September 12, 2017 2:56 pm

    ‘Nothing Unusual About Hurricane Irma’ in terms of US landfalls – apart from the overblown (pun intended) media circus.

    Of course hurricanes must be taken seriously, but ridiculous over-hype is not the way to go.

  4. Rowland H permalink
    September 12, 2017 3:07 pm

    Um, Harvey and Irma this year, not last year in the table!

  5. John F. Hultquist permalink
    September 12, 2017 3:19 pm

    … flooding seems to have occurred up in Jacksonville …

    From Wikipedia:
    The state of Florida, including Jacksonville, is a huge flat plateau with a high water table, and surface lakes are very shallow.[45] The United States Geological Survey states that the highest point in Jacksonville is only 40 feet (12.2 meters) above sea level, making the area susceptible to flooding and storm surge.[46] ”

    Use the coordinates below and Google Earth to check the elevation of the land just north of the center of Jacksonville. At this street intersection you are 1 foot above sea level.

    30.333651, -81.652136

    An oblique aerial view will show how flat the region is. “Street view” in residential areas do not show elevated buildings.
    Use this search string with the “Images Tab” to see alternatives:
    [ elevated houses flood prone areas ]

  6. NeilC permalink
    September 12, 2017 3:24 pm

    I have just put a post IRMA Observations Analysis. 40 locations/bouys for Florida as IRMA went from N to S.

    It’s at http://www.weatherblog.uk

    I’m not sure the comments work tho.

  7. NeilC permalink
    September 12, 2017 3:26 pm

    South to North of course, should edit before posting

  8. erastvandoren permalink
    September 12, 2017 4:51 pm

    Paul, please look at the actual wind measurements, Irma hit Florida with max speed of 62 knots, which is under the hurricane strength.
    You may search the data here http://www.ndbc.noaa.gov/radial_search.php?storm=at1

  9. 4TimesAYear permalink
    September 12, 2017 7:19 pm

    Reblogged this on 4timesayear's Blog.

  10. September 12, 2017 8:53 pm

    Do not forget that except for about 15 miles along the east and west coastlines, Florida peninsula south of Lake Okeechobee is all the Everglades (except where foolishly drained for sugarcane just south of Okeechobee. North of Okeechobee all the way to Orlando the same central region is swampy mixed palmetto scrub and cypress ‘islands’. Everglades without permanent fresh water (Everglades is a very wide, shallow, slow moving river, NOT a swamp). A lot of the palmetto scrub has been dozed and ditched to make poor quality grasslands for beef cattle. Point is, nothing in central Florida peninsula until Orlando. Virtually all the population south of Orlando is concentrated on the two coasts so extremely vulnerable to hurricanes no matter how good the building codes are made.
    Our Fort Lauderdale beach building is post Andrew steel reinforced concrete with hurricane windows. We took no damage, but a new 12 floor next door neighbor due north had a single ocean balcony pane fail, water everywhere, now boarded up and drying. Our end neighbor one over to the SE has three rooms flooded when the wind pushed water in off her large balcony through the massive hurricane glass/aluminum drrains through the necessary extruded aluminum roller guide ridges. Overtopped for hours the about 5-6 cm high near 1/4 inch thick sills.

  11. TexanForever permalink
    September 15, 2017 2:41 am

    Did Michael Mann “contribute” in any way to these data?

  12. September 19, 2017 3:25 am

    Reblogged this on Climate Collections.

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