Atlantic disturbances 95L and 96L are expected to develop soon ”Yale Climate Connections



Nicholas is no longer, after being demoted to a post-tropical minimum on the Louisiana coast on Thursday morning (for a full account of Nicholas’ weather impacts, see the latest NOAA Storm Summary). However, two tropical disturbances in the Atlantic – 96L off the coast of North Carolina and 95L in the eastern tropical Atlantic – are expected to become tropical cyclones within the next two days.

Hurricane chasers to investigate disruption 96L off North Carolina

Intense thunderstorm activity increased Thursday morning in association with an area of ​​disturbed weather, designated 96L, located about 250 miles south-southeast of the Outer Banks of North Carolina. Satellite imagery showed that 96L had multiple surface vortices, but no well-organized surface circulation. A hurricane-chaser plane mission to 96L on Wednesday did not find the system classified as a tropical depression, but a second mission scheduled for Thursday afternoon has a better chance of finding that a tropical depression has formed.

96L has good model support for development through Saturday as it moves north to northeast at 10-15 mph, staying a few hundred miles off the mid-Atlantic coast. Conditions are marginally favorable for development, with sea surface temperatures of around 28 degrees Celsius (82 ° F), a mid-level humid atmosphere with relative humidity of around 70% and moderate to moderate wind shear. high from 15 to 25 knots. From Thursday night to Saturday, 96L will likely bring an inch to two inches of rain over the Outer Banks of North Carolina, as well as waves of 5 to 10 feet in the waters along the mid-Atlantic coast.

By Sunday, 96L is expected to turn northeast and cross past the northern limit of the Gulf Stream, where the waters are colder than 25 degrees Celsius (77 ° F). Windshear will also increase on Sunday, and 96L could then take on subtropical storm characteristics. The guiding currents favor a runway a few hundred miles off the Canadian Maritime provinces, and 96L could bring one to two inch rains over parts of Nova Scotia and Newfoundland on Sunday. The steering currents are expected to collapse on Monday, causing a slow and erratic 96L shift a few hundred miles south of Newfoundland for several days. In its tropical weather forecast for Thursday at 8 a.m. EDT, the National Hurricane Center gave 96L a 70% 2-day and 5-day development probability. The next name on the Atlantic storm list is Odette.

Figure 1. Visible satellite image of disturbance 95L in the eastern Atlantic at 11:35 a.m. EDT on September 16, 2021. The disturbance was poorly organized and had a limited amount of severe thunderstorms. (Image credit: Tropical bites)

Little change at 95L in the eastern tropical Atlantic

A tropical wave in the eastern Atlantic, about 800 miles west-southwest of the Cabo Verde Islands at 8 a.m. EDT Thursday morning, was heading west at 15 mph. This wave, which NHC has referred to as the 95L, has not been organized in recent days, despite apparently favorable development conditions. Satellite imagery showed that 95L has some degree of rotation, but a relatively poor area of ​​severe thunderstorms.

95L, with favorable conditions for development this week, has modest model support for development. From Thursday to Sunday, the disturbance will have sea surface temperatures near 28 degrees Celsius (82 ° F), predominantly moderate windshear of 10 to 20 knots and a moderately humid atmosphere with an average relative humidity of 55 to 65%. These conditions should allow the system to transform into a tropical depression by Sunday. However, the 95L is expected to face a major obstacle to further intensification by Monday, as it approaches the Leeward Islands, due to a broad low pressure trough aloft. This trough is expected to have strong wind shear and dry air, and many model predictions indicate that 95L is destroyed when it meets the trough. In its tropical weather forecast for Thursday at 8 a.m. EDT, the NHC gave 95L a 2- and 5-day development probability of 70% and 80%, respectively. The next name on the Atlantic storm list after Odette is Peter.

Bob Henson contributed to this article.

Website visitors can comment on “Eye on the Storm” posts. Please read our Feedback policy before posting. Comments are generally open for 30 days from the date of posting. Sign up to receive email announcements of new publications here. Twitter: @DrJeffMasters and @bhensonweather


Leave A Reply

Your email address will not be published.