By AccuWeather senior meteorologist
Updated Jun. 11, 2021 5:16 PM EDT
"All is relatively quiet" across the Atlantic basin right now, as AccuWeather Chief Broadcast Meteorologist Bernie Rayno pointed out, but that could change in the coming days.
That's why AccuWeather meteorologists continue to monitor the tropics with their focus glued on the western Gulf of Mexico for potential development and impact in a flood-weary area of the United States that has been inundated by round after round of torrential rainfall over the past several weeks. A tropical system could brew gradually in the region and become a threat to the U.S. around the middle of June. There are a few other areas of concern worth noting, AccuWeather forecasters say.
It is unlikely that explosive tropical development will occur in the western Gulf due to environmental conditions, but there is likely to be some tropical feature of interest in the form of a weak disturbance or a tropical depression, AccuWeather forecasters say. The possibility exists that a system could gradually develop into a named storm over the western part of the Gulf of Mexico over the days spanning June 15-19. The next name on the 2021 Atlantic hurricane season list is Bill.
On Thursday, AccuWeather meteorologists raised the risk from a low to medium chance of tropical development in the zone -- and the potential area over which a threat could emerge was expanded farther to the north in the Gulf of Mexico, creeping closer to within a hundred miles of the Texas and Louisiana coastlines, on Friday.
AccuWeather meteorologists have been cautioning about development toward mid-June in the western Gulf and the northwestern Caribbean since the start of the month.
"With at least marginally favorable environmental conditions expected, there is a low to medium chance for tropical development in the western part of the Gulf of Mexico next week," AccuWeather Senior Meteorologist Rob Miller said.
Water temperatures over the Gulf of Mexico range from the low to middle 80s F, which is plenty warm enough to support a tropical system. A typical threshold for development is considered to be around 80 F, according to AccuWeather meteorologists.
CLICK HERE FOR THE FREE ACCUWEATHER APP
Wind shear has been decreasing across the region and is expected to remain relatively low through much of next week. Low wind shear can create a favorable environment for tropical systems to take shape, especially when other conditions can act as catalysts for formation.
Dust, another factor along with dry air, is associated with that sometimes impedes tropical storm formation, has blown thousands of miles to the west from the Sahara Desert in northwestern Africa. However, it seems to be settling over the southern part of the Caribbean -- well south of the zone of interest.
If a system develops, there are several possibilities for its future track that AccuWeather forecasters are considering for late next week. The scenarios encompass a wide range spanning a landfall in northeastern Mexico to a strike along the central Gulf Coast of the U.S., Miller said.
Steering winds are forecast to remain light in the region. Should a tropical system slowly take shape, it could linger over the western Gulf, wander ashore in northern Mexico before too long or perhaps drift northward over the western Gulf and maybe inch closer to the western or central Gulf Coast of the U.S.
People who live along the Gulf Coast from Mexico to Texas, Louisiana, Mississippi, Alabama and the Florida Panhandle should continue to monitor the situation. AccuWeather will continue to provide updates on this zone and other areas of concern in the tropics.
AccuWeather forecasters say that disruptions to petroleum operations cannot be ruled out in the western and northern Gulf of Mexico next week.
There is a chance for heavy rain from this feature, whether it's strong enough to warrant a name or not, to inundate parts of coastal Texas, Louisiana and Mississippi. Those places have been hit hard with torrential rain and flooding in recent weeks. Some communities, like Victoria, Texas, and Lake Charles, Louisiana, have been soaked by around 2 feet of rain since May 1. Close to a dozen river gauges in eastern Texas and Louisiana remained in moderate and major flood stages on Friday, according to the National Weather Service.
Even if nothing more than a poorly organized, weak tropical feature were to form, seas and surf can build and a plume of drenching showers and thunderstorms may expand northward and perhaps westward along the Gulf Coast of the U.S. next week.
The Gulf of Mexico is not the only zone near North America that AccuWeather meteorologists are monitoring.
On this image, captured Friday, June 11, 2021, the region surrounding Central America has trended much more busy in terms of showers and thunderstorms since the start of the week in response to the formation of the Central American gyre. (CIRA at Colorado State/GOES-East)
There are two areas that will be under close scrutiny for potential tropical development over the eastern Pacific in the next few days, according to Miller.
The first is a broad area of low pressure spinning just south of the southern coast of Mexico Friday. Showers and thunderstorms were erupting in the vicinity of the disturbance.
"Environmental conditions remain favorable, and some slow development into a tropical depression or storm is possible as this low drifts northward," Miller explained.
Another area in the eastern Pacific that has a medium chance of development over the next few days was located about a thousand miles off the coast of Mexico. This feature is not expected to affect land.
Even apart from those two budding disturbances in the East Pacific, the general weather pattern will trigger locally flooding rainfall and gusty winds across portions of southern Mexico into Central America into early next week.
"Formation of the Central American gyre seems to be underway," AccuWeather Senior Meteorologist Rob Miller said.
Rayno echoed that a gyre will help to set the pattern into motion, and while the concept may sound complex, it's actually quite simple, he explained. "There's a little weakness in the jet stream that's going to be coming on south heading into this weekend," Rayno said. He went on to explain that the northwesterly flow of air associated with that plunge in the jet stream will clash with an easterly flow of air over the Caribbean. That collision will help to create a general counter-clockwise circulation in the area.
Unsettled weather with showers and thunderstorms can easily erupt in the pattern. Any time complexes of thunderstorms form and linger over warm waters, there is the potential for a tropical system to organize gradually.
"This particular gyre seems to be centered over southern Mexico, Guatemala and Belize with showers and thunderstorms erupting in southern Mexico, the upper part of Central America, the southwestern Gulf of Mexico, the northwestern part of the Caribbean and over the eastern Pacific along the southern coast of Mexico," Miller explained.
Thousands of miles to the northeast, there is another area that AccuWeather meteorologists have been monitoring this week for potential development this weekend to early next week.
A non-tropical storm is forecast to become stationary along a stalled front off the coast of the Carolinas this weekend.
"Should the storm linger long enough over the warm waters of the Gulf Stream, there is a low chance for this storm to acquire some tropical characteristics," Miller said.
Steering breezes would eventually direct this storm away from the U.S. and out to sea where weakening is likely as it tracks over cooler waters during the middle of next week.
Seas and surf along the mid-Atlantic and southern Atlantic coast can remain agitated due to the proximity of the front and a bubble of high pressure offshore that can create an onshore breeze. The frontal zone will also generate a broad zone of showers and thunderstorms that will extend well inland over the Eastern states into next week.
AccuWeather's team of expert meteorologists predicts a very active year in terms of the number of named systems. AccuWeather forecasters have also warned of the potential for several direct impacts on the U.S. The team is calling for anywhere from 16 to 20 named storms, with seven to 10 expected to strengthen into hurricanes. AccuWeather forecasters anticipate three to five direct impacts on the U.S. this hurricane season.
The 2020 Atlantic hurricane season set a record with 30 named systems, 14 of which strengthened into hurricanes. There were a record 12 landfalls in the U.S. last year. For comparison, an average hurricane season yields around 14 named storms, with about seven that go on to strengthen into hurricanes, based on data over the 30-year period from 1991 to 2020.
MORE WEATHER NEWS:
Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier, Spectrum, FuboTV, Philo, and Verizon Fios.
No comments:
Post a Comment