Status:Ongoing analysis Material from: Linus, ...
1. Impact
Hurricane Dorian formed on 24 August in the central Atlantic, and caused huge damages on Bahamas on 1-2 September. The cyclone later affected the U.S east-coast and also Canada.
https://en.wikipedia.org/wiki/Hurricane_Dorian
https://www.bbc.co.uk/news/world-latin-america-49602445
2. Description of the event
An animation of infrared satellite images for the full lifetime of the cyclone can be found here (from Kimberly Wood, Mississippi State University): http://arashi.geosci.msstate.edu/images/2019Dorian.mp4
A radar loop from Bahamas can be found here (thanks to Brian McNoldy, University of Miami): http://bmcnoldy.rsmas.miami.edu/tropics/dorian19/Dorian_1-3Sep19_bahamas.gif
3. Predictability
3.1 Data assimilation
The assimilation cycle on 28 August 12UTC had problem to determine the position of the cyclone. This was caused by large first-guess errors, as seen in the plot below.
3.2 HRES
3.3 ENS
The plots below show tropical cyclone strike probability on 25-28 August, in forecasts from 25 (first plot) to 22 August (last plot).
The plots below show the tracks (ensemble -grey, HRES - red, ENS control - blue, best track - black), position and intensity on 3 September 00UTC (ensemble - squares, best track - hourglass) in forecasts from 3 September (first plot) to 23 Augsut (last plot). The cyclone was recognised as a tropical storm on 25 March.Three main shifts in the tracks: Majority of members towards Bahamas (26 Aug), easterly path (28 August) and northward turn (31 August)
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3.4 Extended-range forecasts
Tropical storm strike probability 2-9 September in extended-range forecasts, starting from the latest forecast (2 September). The first extended-range forecast to pick up the signal was 26 August, an expected result from the medium-range plots.
Accumulated cyclone energy 2-9 September in extended-range forecasts. All forecasts from 26 August and earlier indicated less activity than normal.The signal for the activity in the Atlantic in the early forecasts originated from the south-eastern part of the basin, where Gabrielle later formed.
