May 29, 2015
year's season got off to an early start with tropical storm Ana, which
developed off the southeast coast earlier this month, but NOAA
forecasters say that the overall 2015 Atlantic hurricane season
will likely be below-normal.
NOAA forecasters predict below-normal hurricane season
For the hurricane season, which officially runs from June 1 - Nov. 30,
NOAA is predicting a 70 percent likelihood of six to 11 named storms
(winds of 39 mph or higher), of which three to six could become
hurricanes (winds of 74 mph or higher), including up to two major
hurricanes (Category 3, 4 or 5 with winds of 111 mph or higher).
While a below-normal season is 70 percent likely, there is also a 20
percent chance of a near-normal season, and a 10 percent chance of an
“A below-normal season doesn’t mean we’re off the hook. As we’ve seen
before, below-normal seasons can still produce catastrophic impacts to
communities,” said NOAA Administrator Kathryn Sullivan, referring
to the 1992 season in which only seven named storms formed, yet the
first was Andrew – a Category 5 Major Hurricane that devastated South
“The main factor expected to suppress the hurricane season this year is
El Niņo, which is already affecting wind and pressure patterns, and is
forecast to last through the hurricane season,” said Gerry Bell, lead
seasonal hurricane forecaster with NOAA’s Climate Prediction Center.
“El Niņo may also intensify as the season progresses, and is expected
to have its greatest influence during the peak months of the season,"
Bell said. "We also expect sea surface temperatures in the tropical
Atlantic to be close to normal, whereas warmer waters would have
supported storm development.”
Included in today’s outlook is Tropical Storm Ana, but its pre-season
development is not an indicator of the overall season strength, NOAA
said. Ana’s development was typical of pre-season named storms, which
often form along frontal boundaries in association with a trough in the
jet stream. This method of formation differs from the named storms
during the peak of the season, which originate mainly from low-pressure
systems moving westward from Africa, and are independent of frontal
boundaries and the jet stream.
With the new hurricane season comes a new prototype storm surge
watch/warning graphic from NOAA’s National Hurricane Center,
intended to highlight areas along the Gulf and Atlantic coasts of the
United States that have a significant risk of life-threatening
inundation by storm surge from a tropical cyclone.
The new graphic will introduce the concept of a watch or warning
specific to the storm surge hazard. Storm surge is often the greatest
threat to life and property from a tropical cyclone, and it can occur
at different times and at different locations from a storm’s hazardous
addition, while most coastal residents can remain in their homes and be
safe from a tropical cyclone’s winds, evacuations are often needed to
keep people safe from storm surge. Having separate warnings for these
two hazards should provide emergency managers, the media, and the
general public better guidance on the hazards they face when tropical
Also new this season is a higher resolution version of
NOAA's Hurricane Weather Research and Forecasting model
(HWRF), thanks to the upgrades to operational computing. A new
40-member HWRF ensemble-based data assimilation system will also be
implemented to make better use of aircraft reconnaissance-based Tail
Doppler Radar data for improved intensity forecasts. Retrospective
testing of 2015 HWRF upgrades demonstrated a five percent improvement
in the intensity forecasts compared to last year.
This week, May 24-30, is National Hurricane Preparedness Week. To
help those living in hurricane-prone areas prepare, NOAA offers
hurricane preparedness tips, along with video and audio public service
announcements at www.hurricanes.gov/prepare.
"It only takes one hurricane or tropical storm making landfall in your
community to significantly disrupt your life,” said FEMA Deputy
Administrator Joseph Nimmich. “Everyone should take action now to
prepare themselves and their families for hurricanes and powerful
storms. Develop a family communications plan, build an emergency supply
kit for your home, and take time to learn evacuation routes for your
area. Knowing what to do ahead of time can literally save your life and
help you bounce back stronger and faster should disaster strike in your
NOAA will issue an updated outlook for the Atlantic hurricane season in
early August, just prior to the historical peak of the season.