HOUSTON - For 34 years, Colorado State University has been forecasting tropical activity in the Atlantic basin. Houston is part of that region, located along the the Atlantic basin's Gulf of Mexico. This type of season forecast is used to gage risk for residents and insurance companies. Just like in Russian Roulette, the more tropical systems forming in the ocean, it's agreed that higher chances will exist for a strike.
This season, CSU -- led by Dr. Philip Klotzbach -- is forecasting 11 named tropical systems, compared to the average amount of 12. Out of those, his department forecasts 4 will become hurricanes, compared to the typical 6 to 7 in any given season. He's maintaining we'll probably see an average of 2 major hurricanes (winds over 111mph), which is considered normal.
CSU updates their seasonal outlook several times per year in the months just before and during the period between June 1st and November 30th. The next forecast update is scheduled to be released June 1st, followed by a third update on July 2nd and a final update on August 2nd. The progress of what's expected to be an El Nino forming -- and other, "teleconnection" large-scale, long-duration weather patterns -- thought to affect hurricane development, are considered in these later updates. The numbers are adjusted accordingly.
Verifying their April forecasts over the last decade, compared to what was observed, I found mixed results. Generally, their forecasts were better than nothing -- with accuracy greater than 50/50, and found they're close to 80% accurate from year to year on the overall number of named tropical systems (tropical storms and hurricanes) that develop. Forecasting an exact number of hurricanes from year to year proves more challenging, with closer to 60% accuracy of forecast verses observation.
I've personally met Dr. Gray (who died last April at 86yo and will be missed!) and Dr. Klotzbach at several weather conferences over the years, and realized immediately that they were by far the smartest guys in the room. It's hard enough forecasting the next 5 to 7 days, much less the next 5 to 7 months. Kudos to their team for starting what so many other private and commercial organizations have since emulated.
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