Today, the National Oceanic and Atmospheric Administration (NOAA) issued its updated Atlantic Hurricane Outlook. Consistent with the update issued by Phil Klotzbach and Bill Gray earlier this week, NOAA has lowered its projections due, in part, to the developing El Niño. NOAA is now predicting a “50 percent probability of a near-normal season, a 40 percent probability of a below-normal season, and a 10 percent probability of an above-normal season. Forecasters say there is a 70 percent chance of seven to 11 named storms, of which three to six could become hurricanes, including one to two major hurricanes.”
That may seem like a lot of uncertainty given the range of named storms and hurricanes and the attached probabilities. However, this is consistent with the National Research Council publication “Completing the Forecast: Characterizing and Communicating Uncertainty for Better Decisions Using Weather and Climate Forecasts.” The report states “Uncertainty is thus a fundamental characteristic of weather, seasonal climate, and hydrological prediction, and no forecast is complete without a description of its uncertainty.” We may want a deterministic forecast, but the state of the science suggests it is not possible to do so with a high degree of reliability.
NOAA wisely cautions the public not to let its guard down. Significant hurricanes have made landfall in the United States during El Niño years. Examples include Betsy in 1965, Bob in 1991, Danny in 1997, and Lili in 2002.
NOAA’s past hurricane season outlooks and verifications can be found at http://www.cpc.ncep.noaa.gov/products/outlooks/hurricane-archive.shtml.