Tips for "Other" Hurricane Outlooks

The CSU Team initially releases a pre-Season Tropical Outlook in December, for the upcoming Hurricane Season.  Several other forecast services then use this outlook as the foundation for their outlooks in the Spring, perhaps adjusting a number or two here/there, or tossing in a different causal explanation.  Proper statistical meteorology practices require fixed-width or fixed-confidence ranges to be provided, but the "single-number Storm prediction" has captured the attention of the public/user/media community.

The bottom line is 12 of the past 14 Seasons have produced more Storms than the long-term average (with only 1997 being below), and this trend is likely to continue during this active cycle of which we are in the midst.  Without a major El Niño anywhere to be found odds are obviously skewed towards an active Tropical Storm Season again in 2009.  There is no scientific basis for anyone to proclaim a Tropical Storm total outside the range of 10-16 until the Season is well under way, and anyone who comes out with a wildly smaller or larger number is doing so strictly as an attention-grabbing dart throw.

Tips for pre-Season Ocean/Atmosphere parameters:

It's unfortunate that "spin" is used for Tropical prediction in light of the potential consequences, but it nonetheless exists. For example, the proclamation "25% few storms than last year!" could be made, but it conceals from the reader that the statement would still translate to 12 Named Storms (an active Season similar to the 2002 Season).  Furthermore, the percentage of Tropical Storms that evolve into Hurricanes and the number of Hurricanes that make U.S. landfall any given year, are very much at the whim of local environmental conditions and synoptic steering patterns that can only be accurately assessed as the Season is underway. So be wary of headlines such as "Could this be the year New York City gets the Big One?" - of which there is nothing inherently wrong with the question itself, except for the fact that some folks make this prognostication EVERY Spring.

Another perennial approach (either innocently or agenda-driven) is over-weighting of Sea Surface temperatures and anomalies [SSTAs] in the early Spring months. SSTAs can ebb, flow and flip signs 3-4 times between March and July, so their Seasonal credence in early Spring is worth about the same as Opening Day stats has on one's Baseball Season.  In much the same way as weekly NINO 3.4 aberrations are not appropriate to assess multi-month ONI status, monthly Atlantic SSTA aberrations are not appropriate to assess multi-Decadal AMO status.  In recent history, cool SSTs across the Gulf of Mexico and Caribbean into May obviously did not inhibit Hurricane IVAN in 2004, and cool SSTs across the Main Develop Region [MDR] into June obviously did not inhibit 16 Tropical Storms from forming in 2008.

This year, SSTAs are ironically unseasonably warm across the Gulf of Mexico - which is probably the bigger SST "concern" considering early-Season storms typically blossom near North America. We will of course keep you abreast of the Season's evolution, storm prospects, and our Hurricane intensity & path predictions.

Tips for popular CSU Hurricane Outlooks:

Despite some fanatical proclamations which sprout every year, there is quality tropical research and statistical predictions emanating from a variety of legitimate scientific entities.  Over the past decade, the most popular and widely heralded of these "Hurricane Forecasts", has come out of Colorado State University [CSU], more commonly coined simply "Dr. Gray's Forecast" (referring to Professor Emeritus Dr. William Gray who headed the Tropical Team).  Dr. Gray has partially moved on to other climate projects, and now Dr. Klotzbach heads the team responsible for what is still the benchmark of Seasonal Atlantic Hurricane Outlooks. 

On Tuesday April 7th, they are scheduled to issue their first Hurricane Season Forecast of 2009 which will undoubtedly garner media, public and industry attention.  Below is our best estimate of the key numbers they will declare (along side historical averages), to help you prepare for any impacts they may cause:

                        1950-2000 Average:      OUR Anticipated CSU Forecast: 

Named Storms                    9.6                        13                   

Hurricanes                          5.9                     6                           

Intense Hurricanes               2.3                         3