The tropical Atlantic Ocean is brimming with activity, making up for weeks of quiescence. Tropical Depression 8 in the Gulf of Mexico is flirting with tropical storm intensity as it drifts northwest, set to impact the western Gulf Coast, particularly Texas, with heavy rains and the potential for some wind and storm surge threats as well.
Meanwhile, nearly 2,000 miles to the east, Tropical Storm Gonzalo is drifting west toward the Windward Islands. As of Thursday morning, the storm was getting closer to hurricane intensity.
If thats not enough storminess for coastal residents to worry about, a third tropical system could soon materialize off the west coast of Africa, meaning that the sudden spate of storminess is unlikely to end anytime soon.
[NOAA predicts Atlantic hurricane season will be unusually active]
Most pressing as of Thursday morning was the disturbance lurking in the Gulf of Mexico, with little in its way other than its own disorganization so far to inhibit strengthening. Tropical storm watches are already up for the Texas Coastline, where the system will likely make landfall this weekend.
If the system is named in the coming day, Hanna is up next. If its a named system, it would obliterate the previous record for the earliest H storm in an Atlantic hurricane season, currently held by Tropical Storm Harvey. That storm formed on August 3, 2005.
The record-busy start to the 2020 hurricane season has already featured the earliest “C”, E”, and “F” storms on record Cristobal, Edouard, and Fay. Gonzalo became the earliest G storm early Wednesday, beating out Tropical Storm Gert, which struck Mexico after forming in the Bay of Campeche on July 24, 2005.
On average, a seasons seventh named storm doesnt spring up until mid September.
A homegrown tropical threat could soon become Tropical Storm Hanna
Close to home, all eyes Thursday morning were on the area of disturbed weather in the middle of the Gulf of Mexico. The system is a tropical depression, the precursor to a tropical storm.
On satellite imagery, a mass of shower and thunderstorm activity was readily apparent over the central Gulf, a discernible broad swirl already steering isolated showers and thunderstorms as they pinwheel into areas between Florida and Louisiana. Counterclockwise inflow near the surface was feeding the brewing system, while outflow exiting the storm aloft fanned out clockwise. Its clear that the system, dubbed Tropical Depression 8, is becoming more organized. However, it is doing so at a slow pace, which limits its potential intensity at landfall.
A scatterometer onboard the MetOp satellite, which provides information about winds near the Earths surface, revealed a coherent low-level closed circulation on Thursday morning, which is a sign that the depression is becoming more organized. It was lacking in strength temporarily, with relatively weak winds of less than tropical storm intensity (39 mph or greater).
The forecast from the National Hurricane Center shows the storm making landfall along the central Texas coastline later Saturday into early Sunday as a tropical storm.
With ample warm water and calm upper-level winds leaving the tropical depression undisturbed, there is a chance it could ultimately strengthen more than currently anticipated, and become a strong tropical storm.
The official forecast calls for its sustained winds to peak at 50 mph, but if it grows stronger there would be an increase the threat of at least low-end storm surge flooding along the Texas coast.
The main threat from this storm is heavy rain and potential flooding. The heaviest rain looks to fall between Corpus Christi and Matagorda Bay and then southwestward toward the Rio Grande, though some heavy rains will be possible for places like Houston and Galveston, too.
Texas has been hit hard by the coronavirus pandemic, with Houston, Galveston and Corpus Christi all seeing an increase in cases, hospitalizations and fatalities during the past month. This need for precautions against the spread of covid-19 adds another layer of complexity to the task of preparing for this storm.
A widespread 3 to 5 inches of rain is a safe bet, with higher totals not out of the question.
Gonzalo may become the first Atlantic hurricane of 2020
On Wednesday, Tropical Storm Gonzalo formed over the open Atlantic about 1,200 miles east of the Windward Islands. Its slowly churning west, but the diminutive system was fighting off dry air originating over the Sahara Desert, which is attempting to choke the system from the north.
Dry air has eroded the western side of Gonzalos incipient eyewall structure, leaving it susceptible to further disruption and potential weakening.
It looks like #Gonzalo’s convective diurnal max did not go smoothly.
An AMSR2 microwave pass (0450 UTC) suggests Gonzalo ingested dry air from the west, choking off convection on 89GHz w/ Arc clouds seen on 37GHz. This leaves Gonzalo’s fragile core unprotected & susceptible. pic.twitter.com/Qz8l0lns2j
— Philippe Papin (@pppapin) July 23, 2020
On Thursday morning, the system had a small doughnut of 65 mph winds at its center; tropical storm force winds exceeding 39 mph only extended outwards 35 miles. According to the National Hurricane Center, Gonzalo is expected to continue gradual strengthening if it can outrun the pernicious affects of the encroaching Saharan Air Layer and could become the Atlantics first hurricane of 2020.
Gonzalos minuscule size makes it especially sensitive to subtle changes to its surrounding environment. Predicting its intensity will be a challenge as it drifts westwards towards the Windward Islands. A hurricane watch is up for Barbados, St. Vincent, and the Grenadines. Thats where winds surpassing 60 or 70 mph are possible, along with 2 to 4 inches of rainfall. Localized totals could top half a foot.
Uncertainty abounds after Gonzalo enter the Caribbean. A wide range of possibilities is supported by computer models, ranging between full dissipation to further strengthening.
A long season ahead
At the same time, a third tropical wave will exit the coast of Africa on Friday, and is projected to develop as it moves west this weekend.
Atmospheric scientists have warned that this season could be particularly active. This is due to factors ranging from a developing La Niña event in the tropical Pacific Ocean, which tends to favor a more active Atlantic season, to above average sea surface temperatures in the so-called main development region of the Atlantic. The warmer than average waters can provide more fuel for stronger, wetter storms that inflict more damage.
[NOAA predicts Atlantic hurricane season will be unusually active]
Warm waters also help enable tropical cyclones to rapidly intensify. Climate scientists have found the incidence of rapidly intensifying storms could become more frequent as waters continue to warm due in large part to human-induced climate change.
Andrew Freedman contributed to this report.