Despite nearly unanimous predictions that there would be above-average activity, it’s been an ominously quiet start to hurricane season — though that could still change in the coming weeks.
There are signs that, after a quiet week ahead, a reversal could be in the cards for the final few days of August. The National Hurricane Center has outlined one system to watch and indicated that a sudden uptick in activity is possible. It’s far from a guarantee, but it also stands to reason that the tropical slumber can’t last forever.
The historic peak of hurricane season is around Sept. 15, but most of late August into mid-October is regarded as the busiest stretch of weeks when it comes to tracking the tropics. A given season averages 14 named storms, seven of which might be hurricanes, but NOAA forecasters have continued to echo earlier calls for 14 to 20 named storms, six to 10 hurricanes and three to five major hurricanes.
No Atlantic named storms since #Colin weakened to a tropical depression on July 2nd, and none forecast for the next 5 days per National #Hurricane Center. The last time that the Atlantic had no named storm activity between July 3 and August 16 was 1999. pic.twitter.com/4zKdY0OTPK— Philip Klotzbach (@philklotzbach) August 11, 2022
Even the quietest seasons have whipped up meteorological monstrosities.
For instance, there were only seven named storms in 1992, but the first was Category 5 Hurricane Andrew, which lay siege to South Florida and raked the National Hurricane Center headquarters with a wind gust to 163 mph. Conversely, what may have been busier seasons on paper have had comparatively lesser human impacts when storms have spent their lives over the open ocean.
But when it comes to tropical storms and hurricanes, it only takes one.
Tropical disturbance in Caribbean
On Wednesday morning, the National Hurricane Center was monitoring a disturbance centered near the coast of northern Honduras. The bulk of any inclement weather, including some robust thunderstorm activity, was located to the north of land and over the western Caribbean.
The system is currently lopsided, but it was exhibiting evidence of healthy outflow, or exhaust, at its upper levels. Tropical storms and hurricanes breathe in a sense, and the more they exhale aloft, the more warm, humid air they can ingest near the surface to fuel their continued growth and maturation.
Minimal organization of this disturbance is likely through Thursday, but it will slip into the Bay of Campeche into Friday. There, it will encounter very warm sea surface temperatures — supportive of strengthening — but wind shear is moderate. Wind shear, or a change of wind speed and/or direction with height, is known for playing a tug-of-war game with tropical cyclones. High wind shear can inhibit a storm’s vertical development, often knocking storms off-kilter.
It’s impossible to be certain what may transpire with the system more than about three or four days out, but broadly it’s likely to drift northwest, toward either northern Mexico near Tamaulipas or extreme southern Texas. Localized heavy rainfall is possible if it remains intact, but any forecast beyond that is mere speculation.
The National Hurricane Center estimates a 20 percent chance of eventual development of a well-formed tropical cyclone, but it’s worth monitoring regardless.
The bigger picture
Across the Atlantic, there are signs that activity might start to pick up more notably in the next 10 days.
Weather models are focusing on more aggressive tropical waves rolling off the coast of Africa and propagating west through the MDR, or Main Development Region. The MDR, sometimes called “Hurricane Alley,” is the belt of the tropical Atlantic that can occasionally churn out long-lived powerful storms one after another.
It’s far too early to diagnose simulated waves as a potential storm, but several other current factors could aid storm formation. Wind shear seems likely to take a breather, which may allow for better vertical development of a storm. Dust from the Sahara could also thwart storm formation, but the layer of hot, dry air at the mid-levels of the atmosphere it’s embedded in, should thin with time. That may permit some tropical systems to sprout, particularly as the oceans continue to warm.
The Gulf of Mexico could also become increasingly favorable for potential storms toward the end of the month; the gulf is running about a half-degree to a degree above average in terms of sea surface temperature.
Simply stated, August came in like a lamb — but its exit may not be as mellow.