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Monthly Archives: May 2017

City predictions for the 2017 Atlantic hurricane season

Lower number of named storms, new forecast techniques added & cities more spread out than last year.

According to model data it appears we will have weak elnino conditions in the East Pacific at the height of or later in the Atlantic hurricane season. So what does this mean? a chance of increased wind shear across parts of the Atlantic basin approaching the height of the season Sept 10th. Tropical systems like to develop when calmer conditions are present in the upper levels of the atmosphere. Most development in the Atlantic occurs between August and the end of October when conditions are ripe but it could be different this year. As of just before this post the water temps in the enso region have somewhat cooled but this could have been caused by a temporary shift in trade winds and I still think deep into the hurricane season these SSTs will increase to near or at weak Elnino conditions.


International research institute for climate and society

For an elnino event to be established there needs to be a three month period of 0.5 degrees or greater SST’s in the nino 3.4 region and most models show this happening. This is a strong feature in my eight criteria put into my city predictions based on how many named storms there could end up being. This year I am calling for 12 to 14 named storms, last year I was calling for 14 to 16 named storms and we ended up with 15 named storms in the basin. As a result there will be practically a whole new set of cities chosen to be impacted by a named storm for this year with a couple of leftovers from last season. As for elnino comparisons I researched past seasons with similar SST temperatures in the East Pacific and was able to subjectively choose seven past years that come close to lining up with what the models are projecting listed below.
Elnino Analog years
Climate Prediction Center

METHODOLOGY

So now that you know my main factors for making my city predictions I need to make it clear that one or more of my top 20 may not meet the criteria above. There are several other methods used in arriving at my final list and sometimes these change from year to year depending on each methods success. This years list of methods not necessarily listed in the order of importance below.

  • 12 to 14 named storms finding similar seasons since 1990, were any of my top 20 locations affected in seasons like this? most of top 20 decided based on this criteria,leaning lower towards 12. As of mid May wind shear is screaming across the western Atlantic basin so I think we could get off to a slow start.
  • ENSO (Elnino Southern Oscillation) Comparing past seasons East Pacific sea surface temperatures to what model expectations show for hurricane season. What cities in my top 20 were impacted during these analog years.
  • Cities most due or overdue for all named storms based on av return rates from 1871.
  • Cities most due or overdue for hurricanes only (74 mph & up) av since 1871.
  • Average number of storms when these top 20 locations were directly hit by a hurricane since 1900.
  • NAO North Atlantic Oscillation based on expected positive stage causing higher trade winds & cooler north Atlantic SST’s. Since 1990 what cities were affected in a positive phase based on April stats.
  • Trends Criteria a similar event happening 3 or more times since 1871,(example) A hurricane hit a particular city in 2016 did the city get hit the following year in a similar way?
  • Were any of these top 20 in the top 20 last year? what ranking & for what reason.

  • Introducing the NAO “North Atlantic Oscillation” into my city predictions. For the first 12 years my city predictions were based on mainly return rates & statistical averages. My track record during this period was very good considering I averaged 2 or more of my top 5 cities impacted each season or 10 for 12 with the other two seasons having one/zero cities impacted out of a potential 152. Since introducing ENSO I have zero in 2014 and one in 2015 of my top 5 and just under 50% of the remaining top 20,so adding another factor such as the NAO may make things worse. Needless to say I am not pleased about adding these predictors as the statistical rates have served the process just fine. Continued questions from academia & pros about past statistics not being reliable enough has forced me in to uncharted territory but may be short lived if it does not add value. Using a starting point of 1990 I see if any of my top 20 were impacted in a plus year.

    Using the chart below each location is calculated and the highest amount in each category wins (highlighted in yellow) there are no tie breakers so more than one may be highlighted in each category. My top five picks are the winners with the most yellow boxes, in tie situations weight is put on the significance of each criteria. Fourteen of the locations had no yellow boxes but the closer numbers to the top five locations get the nod in the positioning. Due to the uncertainty of the NAO criteria it is given very low value in positioning.


  • #1)Sable Island,Nova Scotia
  • #2)Gulf Shores,Alabama
  • #3)Marathon,Florida
  • #4)Isle Of Youth,Cuba
  • #5)Cayman Islands
  • #6)Long Island,New York
  • #7)Halifax,Nova Scotia
  • #8)Antigua
  • #9)Dominica
  • #10)Cape May,New Jersey
  • #11)Montego Bay,Jamaica
  • #12)Port Oconnor,Texas
  • #13)Key Largo,Florida
  • #14)Ponce,Puerto Rico
  • #15)Sarasota,Florida
  • #16)Cap Haitien,Haiti
  • #17)Providence,Rhode Island(entire state)
  • #18)Santo Domingo,Dominican Republic
  • #19)Kenedy,Texas
  • #20)Corpus Christi,Texas

  • Each & every year there will be one or more locations affected that I did not pick. My past track record would indicate if you are in my top 20 you statistically have an increased chance for a named storm. If you are in the top five there is a pretty good chance 2 or more locations will be impacted. Last year for example 9 of 20 were impacted by a named storm, not bad considering I am plucking from 152 locations across the Atlantic basin. If you were told you had a 50% chance of being struck by a vehicle at a certain location you would look not just twice maybe three or four times. There is no harm in preparing for hurricane season regardless of your city on this list or not better safe than sorry. It is advisable to know your evacuation & flood zones,know where you will evacuate to and how you will get there,do they take pets?. As time goes by I will be adding my past years predictions notes and verification of what worked or did not work since 2003. This information will be added to my predictions page at Jim’s Predictions where you will also find maps & videos of my predictions. Thank you for your time and good luck this hurricane season.

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