Sunday, August 03, 2014

August Tropical Climatology & CSU Updated Tropical Forecast


Bertha should stay offshore.


# 8910


Having gone through more than a few hurricanes and tropical storms in my 60 years, I take each year’s tropical cyclone season seriously, even though we’ve not seen a serious hurricane threat since Wilma crossed South Florida in 2005. 


Memories of Donna in 1960 (you always remember your first), Betsy in 1965, Agnes in 1972 , and riding out Elena & Bob aboard my sailboat in 1985 – and visiting Biloxi shortly after the destruction of Camille in 1969 and New Orleans six weeks after Katrina – have instilled in me a healthy respect for these tropical systems.


In late May we saw a forecast (see NOAA: 2014 Atlantic Hurricane Outlook) calling for a below-average tropical storm season – a conclusion also shared by Colorado State University’s Dr. William Gray whose June 2nd outlook called for only 10 named storms this year.


In their latest update, Gray and Philip J. Klotzbach continue to see poor oceanic and atmospheric conditions for tropical development, and are still calling for only 10 named storms, four to reach hurricane strength, and one to reach major (CAT 3) status.


Forecast of Atlantic Seasonal Hurricane Activity and Landfall Strike Probability for 2014 - PDF Format

Philip J. Klotzbach and William M. Gray
31 July 2014


We continue to anticipate a below-average Atlantic hurricane season. While we only expect a weak El Niño to develop this year, conditions in the Atlantic basin appear especially detrimental for hurricane formation. Atlantic Main Development Region sea surface temperatures are cooler than normal, sea level pressures are higher than normal, and vertical wind shear throughout the Atlantic basin has been much stronger than normal. Landfall probabilities for both the United States and Caribbean are below their long-period average values.


But, as any Florida native can tell you, it only takes one hurricane to ruin your entire summer.


Despite a relatively slow June & July, August is really when the Atlantic hurricane season really begins to pick up steam, and that trend usually peaks in mid-September. 


Compare the areas of origin and typical hurricane tracks in these two maps (below) showing July and August, and you will see a considerable amount of difference.



As the summer progresses the spawning grounds for Hurricanes moves further east into the warming Atlantic ocean. It isn’t until August and September that the Cape Verde basin begins to produce what often turn into very large and persistent hurricanes.


But, as indicated by the CSU updated forecast above, and the graphic below from NOAA, surface seawater temperatures in the mid and far Atlantic remain relative cool, and inhospitable for tropical development.


How long this condition will persist remains to be seen, but as we are only 1/3rd through the hurricane season, it is a bit too early to pop the Champaign corks.  Hurricane Season runs through the end of November.

You can find much more on Hurricane Climatology at NOAA’s  Tropical Cyclone Climatology page.

This year the state of Florida has published a new preparedness guide, which you can download from the links below.

Florida Emergency Preparedness Guide

2014 Florida Emergency Preparedness Guide

Large Print

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