Tropical Storm Elsa Forms, Forecast To Bring Heavy Rainfall, Gusty Winds To Region On Friday

After being tracked for several days as Invest 97L, and then Potential Tropical Cyclone Five, and then Tropical Depression Five, Tropical Storm Elsa has formed less than 1,000 kilometers east-southeast of Trinidad and Tobago. Elsa is now the earliest 5th named storm on record, breaking 2020’s record with Edouard forming on July 6th.

Based on available forecast data, this system is expected to traverse the Windward Islands on Friday morning through the afternoon as a strong tropical storm.

Specifically for Trinidad and Tobago, while direct impacts are not expected, periphery impacts such as an atypical wind regime, feeder bands (strong showers, thunderstorms, and gusty winds associated with Tropical Storm Elsa), and agitated seas are likely on Friday into Saturday.

The Latest From The National Hurricane Center

Tropical Storm Elsa’s Forecast Track as of 5:00 AM 1st July, 2021. (National Hurricane Center)

At 5:00 AM AST on July 1st, the center of Tropical Storm Elsa was located near latitude 9.4 North, longitude 48.8 West. Elsa is moving toward the west near 41 KM/H. An even faster motion to the west-northwest is expected over the next 24 to 36 hours. On the forecast track, the system will pass near or over portions of the Windward Islands or the southern Leeward Islands on Friday, move into the eastern Caribbean Sea late Friday and Friday night, and move near the southern coast of Hispaniola on Saturday.

The center of Tropical Storm Elsa is located approximately less than 1,000 kilometers east-southeast of Trinidad and Tobago.

Maximum sustained winds have increased to near 65 KM/H with higher gusts to 83 KM/H. Some additional strengthening is forecast during the next couple of days. Tropical-storm-force winds extend outward up to 165 kilometers from the center. The estimated minimum central pressure is 1006 millibars.

Tropical Storm Elsa’s Forecast Track as of 5:00 AM Thursday 1st July 2021. (National Hurricane Center)

Tropical Storm Elsa’s Watches & Warnings

Tropical Storm Elsa’s Tropical Storm Watches and Warnings as of 5:00 AM Thursday 1st July 2021. (National Hurricane Center)

A Tropical Storm Warning is in effect for St. Vincent and the Grenadines, Barbados, Martinique and St. Lucia.

A Tropical Storm Watch is in effect for Guadeloupe.

A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours.

Other Alerts Issued For Several Islands

A number of other alerts are in effect for several islands across the Lesser Antilles, though some may not be under direct threat from Tropical Depression Five’s eventual track as Tropical Storm Elsa.

Trinidad and Tobago, Grenada and its dependencies.

There are no alerts, watches, or warnings in effect for Trinidad and Tobago as of June 1st, 2021. However, the Trinidad and Tobago Meteorological Service issued a statement on Wednesday afternoon advising, “It is likely that feeder band activity associated with the system will produce periods of rain/showers and isolated thunderstorm activity with possible gusty winds on Friday (2nd July 2021) into Saturday (3rd July 2021) over Trinidad and Tobago.”

Grenada’s Meteorological Office has issued a Severe Weather Advisory for Grenada and its dependencies. The Advisory warms of cloudy to overcast conditions with showers (which may become heavy) and thundershowers, accompanied by gusty winds by Friday afternoon. The likelihood of significant impacts is greater for the sister isles of Carriacou and Petite Martinique. According to the advisory, potential impacts are expected to be most significant across the northern section of the state, with a medium chance of flash flooding; downed trees and powerlines, landslides, and rockfalls.

St. Vincent and the Grenadines

In addition to a Tropical Storm Watch, St. Vincent and the Grenadines (SVG) also have a yellow-level marine advisory warning of above normal swells and gusty winds. SVG’s National Emergency Management Organization NEMO is also warning of lahars, mudflows, and flooding.

According to NEMO, “It is expected that whenever rain falls, there will be significant steaming, particularly in the valleys where Pyroclastic Density Currents have come down.  The Pyroclastic Density Currents can result in warm or hot mudflows, which will also steam.  This means that it would not be unusual to have significant steaming in some or all of the valleys on the volcano.  Also, while this steaming would be mainly focused in the upper parts of the valleys, due to the fact that the mudflows can also steam, the steaming can extend all the way down the valley to the coastline.”

Barbados

Alerts in effect from the Barbados Meteorological Service for Barbados as of Thursday morning.

There are several advisories in effect for Barbados over the next 72 hours, concerning excess rainfall, marine interests, severe thunderstorms, and wind.

In addition to the Tropical Storm Warning, the Barbados Meteorological Service has issued a High Surf Advisory, a Small Craft Advisory.

Martinique, Guadeloupe and the French Antilles

Alerts in effect from Meteo France for the French Antilles (Meteo France)

Dominica

While this country is not under any tropical storm watches or warnings at this time, the Dominica Meteorological Service has placed the country under a flood warning until 6:00 AM Thursday as Invest 95L continues to move westward, but still producing heavy rainfall in the region.

The Met Service in that country is warning of “tropical storm-like conditions with winds gusting to tropical storm force from Friday afternoon. Rainfall amounts of 60 mm to 100 mm (2.5 in to 4 in) in moderate to heavy showers are projected with waves near 4.0 m/13.0ft.” A Small Craft Warning is in effect for Dominica.

Tropical Storm Elsa’s Tropical Storm Watches and Warnings as of 5:00 AM Thursday 1st July 2021. (National Hurricane Center)

According to the National Hurricane Center, interests elsewhere in the Windward Islands, Leeward Islands, the Virgin Islands, Puerto Rico, the Dominican Republic, and Haiti should monitor the progress of this system. Warnings and additional watches will likely be required tonight and on Thursday.

Tropical Storm Elsa: Hazards Affecting Land

Tropical Storm Elsa’s probabilities for tropical-storm-force winds as of 5:00 AM Thursday 1st July 2021. (National Hurricane Center)

WIND: Tropical-storm conditions are expected in portions of the Windward and the southern Leeward Islands within the warning area on Friday. Tropical storm conditions are possible in the watch area on Friday.

RAINFALL: The system will produce rainfall totals of 3 to 6 inches with maximum totals of 8 inches on Friday across the Windward and the southern Leeward Islands, including Barbados. This rain may produce isolated flash flooding and mudslides.

Additional island-specific impacts have been mentioned above.

Tropical Storm Elsa probabilities for hurricane-force winds as of 5:00 AM Thursday 1st July 2021. (National Hurricane Center)
Tropical Storm Elsa‘s probabilities for hurricane-force winds as of 5:00 AM Thursday 1st July 2021. (National Hurricane Center)

This system is of no direct threat to Trinidad and Tobago at this time.

Important Note: The current forecast is based on Tropical Storm Elsa moving just south or across Barbados on Friday, then across the Windward Islands. Adjustments in track southward, as noted in this advisory, may increase rain chances for T&T but tropical-storm-force winds are forecast to remain across the northern half of Elsa’s core, thus posing no direct threat to T&T at this time.

Tropical Storm Elsa’s Forecast Discussion

Tropical Storm Elsa (Weathernerds.org)

The tropical cyclone’s cloud pattern became a little better organized overnight, with convective banding features 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 set at 35 kt in agreement with Dvorak estimates from SAB and TAFB, and just slightly above the maximum winds from an earlier scatterometer pass, making the cyclone a tropical storm. 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.

Tropical Storm Elsa’s Forecast Track as of 5:00 AM 1st July, 2021. (National Hurricane Center)

The storm has been accelerating westward overnight, and the initial motion is around 275/22 kt. A strong subtropical ridge is situated to the north of the storm, and this feature should steer the system quickly to the west-northwest for the next 3 days or so. There is significant uncertainty in the track forecast from days 3-5. 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, and within the latter suite of guidance. 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, the fast forward motion could result in some decoupling of the low- and higher-level circulation which would limit strengthening. Also, the potential interaction of the storm with the mountainous landmasses 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 and on the lower end of the guidance suite.

Key Messages:

  1. Tropical storm conditions are expected beginning early Friday in portions of the Windward and the southern Leeward Islands. Heavy rainfall from the system will move quickly across the Windward and the southern Leeward Islands, including Barbados, on Friday. Isolated flash flooding and mudslides are possible.
  2. 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.
  3. 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.

Forecast discussion by NHC Forecasters Pasch.

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