Hurricane Central
By Jonathan Belles
6 days ago
At a Glance
- This hurricane season is expected to be very active.
- Breaks in the season will still be likely.
- Dust, higher pressures and drier air could lead to quieter times.
Sign up for the Morning Brief email newsletter to get weekday updates from The Weather Channel and our meteorologists.
With a very active hurricane season forecast, we’re now looking for factors that can make those outlooks wrong.
Here’s what we know about the season and what could change the ultimate outcome:
The Table-Setting Factors For This Season: Incoming La Niña and A Warm Atlantic
These two factors are the ones that we know will be with us this hurricane season, which as a whole, will likely be busy. NOAA’s most recent outlook for the season predicted the highest number of storms and hurricanes for a forecast issued in May.
Little changes in either of these factors probably won't result in a palpable shift from one week to the next.
In fact, we're expecting some changes. Although cooling in the equatorial Pacific has slowed modestly, La Niña is expected to develop this summer. By the second half of hurricane season, there is an 80% chance of La Niña conditions. These conditions are expected to boost activity in the tropics.
The other headline of the season is the continued well-above-average water temperatures across the Atlantic. These water temperatures are most above average in the North Atlantic and from the Caribbean to the neighboring southwestern Atlantic. Temperatures there are generally 1-3ºC above average.
(MORE: Why The Atlantic Hurricane Season's Active Phase Could Arrive Earlier This Year)
Factors That Add Activity Ebbs and Flows
Neither La Niña nor the warm Atlantic will unleash a constant stream of tropical storms and hurricanes through the end of the season. There will still be active weeks and quiet weeks.
Activity during a given week will depend on smaller-scale features that will tamp down bits of energy or spin them up.
Hurricane season pit stops are still likely: The most immediate factor that will stall activity over the next few weeks is bursts of tropical-wave-eating dust from Africa. Saharan dust is a typical mainstay of July and August across the Atlantic.
The dust causes thunderstorms to dry out and fall apart, and in turn, some tropical waves are unable to survive the trek from Africa to the Caribbean. Mammoth bursts of dust can also act as a temporary shade over the Atlantic that can cool down water temperatures between the Lesser Antilles and Cabo Verde. Relative cooling has been spotted in recent days, although temperatures continue to warm.
Another factor that can actually make the season less active and perceptibly feel less active is higher than typical pressure across the Atlantic.
Advertisem*nt
Pressure is expected to be higher than average both over the Deep South and the Central Atlantic over the next week or two. This will likely limit the number of storms in the short-term and also push any storms that can develop further south and away from the U.S. coastline.
This has already been seen once this season with a tropical low near the Southeast Coast (called Invest 92L), which suffered with higher than usual pressures during its lifetime. Arguably, lower background pressures may have made it easier for the development of a tropical depression or storm.
Of course, we could also have days or even weeks devoid of focusing features that could lead to tropical development even if all the dust clears and the water simmers. All tropical systems need some sort of spin to build upon.
(MORE: A Hurricane's Deadliest Threat Is Rainfall)
Bursts of activity ahead? One weather feature that meteorologists are wary of this time of the year is the late-season cold front. We’re still watching frontal boundaries with some oomph dip into the South and East as we move through late June and early July.
These fronts contain spin along them and they can be an easier spot for tropical development if those fronts can dip into the Gulf of Mexico or into the Atlantic near the East Coast. This is a common formation area in July.
As Jon Erdman has recently written, the most active hurricane seasons typically see an earlier start to the annual peak in hurricane activity. This may creep into the picture on the platform of La Niña and warmer water temperatures, or something smaller like a cold front or a tropical wave that sneaks through African dust.
Any sense that this season will be squelched by dry air or any other mechanism is just hopeful thinking this year.
Now is the time to prepare for this expected busy hurricane season.
MORE ON WEATHER.COM
- Hurricane Season Terms You Need To Know
- How Climate Change Is Affecting Hurricanes
- Five Things We Watch For In July
Jonathan Belles has been a graphics meteorologist and writer for weather.com for 8 years and also assists in the production of videos for The Weather Channel en español. His favorite weather is tropical weather, but also enjoys covering high-impact weather and news stories and winter storms. He's a two-time graduate of Florida State University and a proud graduate of St. Petersburg College.
