What are the chances? Track Tropical Storm Fay with wind probabilities on the Stormpulse map

This afternoon we launched a new feature on the site that should help answer the question of ‘when can I expect winds in my area?’

The National Hurricane Center publishes a product called “Wind Speed Probabilities” in sync with their Forecast Advisories that provide percentages indicating when a storm’s winds are most likely to affect a particular area. This information is presented in a tabular format like so:

  - - - - WIND SPEED PROBABILITIES FOR SELECTED  LOCATIONS - - - -  

               FROM    FROM    FROM    FROM    FROM    FROM    FROM
  TIME       18Z FRI 06Z SAT 18Z SAT 06Z SUN 18Z SUN 18Z MON 18Z TUE
PERIODS         TO      TO      TO      TO      TO      TO      TO
             06Z SAT 18Z SAT 06Z SUN 18Z SUN 18Z MON 18Z TUE 18Z WED

FORECAST HOUR    (12)   (24)    (36)    (48)    (72)    (96)   (120)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
MOBILE AL      34  X   1( 1)   9(10)   8(18)   5(23)   2(25)   1(26)
MOBILE AL      50  X   X( X)   2( 2)   2( 4)   1( 5)   X( 5)   1( 6)
MOBILE AL      64  X   X( X)   X( X)   1( 1)   X( 1)   1( 2)   X( 2)

We here at Stormpulse believe this is great information of great value, but the presentation is too complex and non-visual. So we are capturing, storing, and representing it directly on the map, in the form of bar charts and a reduced table with familiar dates and times.

To access this information, click “Wind Probabilities” ‘On’ using the the layers menu in the top-right corner of the map. After a small delay (as data is retrieved from our server), you should see a small multitude of blue boxes appear, with small white, yellow, and orange bars inside.

These miniature bar charts provide a quick glance of wind probabilities for the storm. Clicking on the bar chart will expose a details box that shows the bar chart in a large format, along with up to three buttons labeled ‘CHANCE BY DAY’. The bar chart shows you the overall likelihood that the location will experience tropical storm, storm, or hurricane force winds. Hovering over ‘CHANCE BY DAY’ will show you the chance of a particular wind force distributed over the next 5 days of the storm’s travel.

Here we see that Mobile, Alabama has, as of Tropical Storm Fay Advisory 29A, a 26% chance of experiencing tropical storm force winds in the next 5 days. Hovering over the top ‘CHANCE BY DAY’ button reveals the table at the right, which tells us that Sunday at 5 AM is the most likely time for the onset of these winds. However, just as you should not focus on the center line of the forecast cone, it is wise to look at the overall distribution of these percentages. There is still a 1% chance that the winds will come the night before (Saturday at 5 PM).

We hope you enjoy the extra insight provided by this information. We still have a few tweaks to make to this feature, we would appreciate any feedback or questions you may have. Those of you that are embedding our tracking map on your own site using the Stormpulse API do not need to do anything to take advantage of this new feature. It will appear on the map automatically.

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