Find out what the Initial Outlooks say about the 2018 Atlantic Hurricane Season
The extremely active 2017 Atlantic hurricane season may have officially ended only a couple of weeks ago, but several groups have already issued their first outlooks for the 2018 Atlantic hurricane season which officially starts on June 1st. The Tropical Meteorology Project (TMP) at Colorado State University will issue its first formal forecast for the 2018 hurricane season on April 5th. They recently released a preliminary discussion where they evaluated the likelihood of several scenarios.
The TMP is currently giving an approximately 60% chance of an above-normal hurricane season, a 35% chance of a near-normal hurricane season and a 5% chance of a below-normal hurricane season for the Atlantic basin in 2018. For reference the median Atlantic hurricane season has about 12 named storms (maximum winds >= 39 mph), 6 hurricanes (maximum winds >= 74 mph) and 2 major hurricanes (maximum winds >= 111 mph).
This forecast was based on the premise that North Atlantic sea surface temperatures are currently much warmer than normal (Figure 1). The development of El Niño (warmer than normal water temperatures in the eastern and central tropical Pacific) seems relatively unlikely for 2018, given the current ocean setup as well as model predictions. Warmer-than-normal sea surface temperatures provide more fuel for developing Atlantic storms. The impacts of anomalously warm sea surface temperatures were clearly evident during this past hurricane season where these warm anomalies helped fuel a very active season. The absence of El Niño indicates that upper-level winds should generally be weaker, thereby creating an environment more conducive for supporting Atlantic hurricanes.
The U.K.-based Tropical Storm Risk consortium recently issued their first outlook for the 2018 hurricane season. Their initial forecast called for a total of 15 named storms, 7 hurricanes and 3 major hurricanes, or a slightly above-normal season. Their outlook was based on the premise that Atlantic low-level winds are predicted to be slightly weaker than the long-term average, creating an environment more conducive for hurricane development and intensification. They also did not anticipate the development of El Niño.
One caveat with this initial outlook is that large changes can happen in the atmosphere-ocean system between December and the start of the hurricane season, so caution must be used when using these outlooks. Seasonal hurricane forecast skill generally improves as the hurricane season approaches. However, it must also be noted that no one can tell you months in advance where hurricanes may make landfall. Regardless, now is an excellent time to make sure that your disaster recovery plan is up-to-date before the hurricane season gets underway.
Figure 1: Mid December 2017 sea surface temperature anomalies across the North Atlantic.
About the Author:
Dr. Phil Klotzbach has received national and international attention for his work in researching weather patterns and forecasting hurricanes. He currently is lead author on Colorado State University’s Atlantic basin hurricane forecasts which he releases every year with his colleague Dr. Michael Bell.