Tropical Depression 5 Becomes Tropical Storm Elsa Overnight

In its 5 a.m. Thursday update of the Atlantic Basin, the National Hurricane Center upgraded tropical depression 5 to Tropical Storm Elsa.

Elsa is the earliest-known fifth named storm on record for the Atlantic basin in the satellite era (1966-present), breaking the record formerly held by Edouard on July 6, 2020.

Notice the beginning of an eye in Elsa at the 5 o’clock position and slight rotation.

Eastern Gulf Probabilities

At 5 a.m. Thursday 7/1/2021, forecasters believe that the eastern Gulf has up to a 30% chance of experiencing tropical-storm-force winds by late this week or early next.

The tropical cyclone’s cloud pattern became a little better organized overnight. Convective banding features are becoming more evident over the western and southwestern portions of the circulation.

Upper-level outflow is well-defined to the west of the system, and restricted over the eastern semicircle. The current intensity is 35 knots, making the cyclone a tropical storm.

The storm has been accelerating westward overnight, and the initial motion is around 22 knots. A strong subtropical ridge should steer the system quickly to the west-northwest for the next 3 days or so. However, there is significant uncertainty in the track forecast from days 3-5.

Disagreement Among Models, High Uncertainty

The ECMWF model turns the cyclone northward after interacting with Hispaniola while the other models such as the GFS, HWRF, and U.K. Met take Elsa across western Cuba and into the southeastern Gulf of Mexico. The official forecast is similar to the previous one last night. However the discrepancy in the models makes confidence in this track lower than usual.

Some intensification is likely for the next day or two, since Elsa is expected to be in an environment of warm sea-surface temperatures, fairly low vertical wind shear, and high mid-level relative humidity.

However, potential interaction of Elsa with the mountainous land masses of the Greater Antilles later in the forecast period could disrupt the circulation somewhat. Therefore the official intensity forecast, like the previous one, is quite conservative.

Key Messages

  1. Tropical storm conditions are expected beginning early Friday in portions of the Windward and southern Leeward Islands.
  2. Heavy rainfall from the system will move quickly across the Windward and southern Leeward Islands, including Barbados, on Friday. Isolated flash flooding and mudslides are possible.
  3. There is a risk of wind and rainfall impacts in portions of the Virgin Islands, Puerto Rico, Hispaniola, Cuba, the Turks and Caicos and the southeastern Bahamas through early next week. Interests in these areas should monitor the system’s progress and updates to the forecast.
  4. Interests in Florida should monitor updates to the forecast for this system, but it is too soon to determine what if any impacts could occur there next week given the uncertainty in the long-range forecast.

There is no forecast threat to the Houston area. Just beware in case you are traveling in the Caribbean or to Florida this week or next.

Posted by Bob Rehak at 6am on 7/1/2021 based on NHC information

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