Tropical Storm Warning in effect for Dominica, schools closed

Prime Minister of Dominica Roosevelt Skerrit announced the closure of the schools on October 20, 2023 due to the adverse weather with Tropical Storm Tammy

Tropical Storm Warning in effect for Dominica, schools closed
Tropical Storm Warning in effect for Dominica, schools closed

Roseau, Dominica: Dominica has been placed under a Tropical Storm Warning as TS Tammy approaches the Leeward Islands. TS Tammy is expected to produce storm total rainfall amounts of 3-6 inches, with maximum amounts of 10 inches, across portions of the northern Windward into the Leeward Islands.

Those rains may produce flash and urban flooding and isolated mudslides in the higher terrain.

DOWASCO urges the public to be prepared. Ensure that you have enough water stored for emergency use as flash flooding poses a threat to our water systems and may result in temporary interruption of service. Some of our systems will also be shut down to protect the water supply.

Store at least one gallon of water per person in your household or more if there are children or elderly persons in your family. Store water in safe, food-grade containers that can be covered securely.

The schools in Dominica have been closed due to adverse weather. PM Roosevelt Skerrit announced the closure of the schools on October 20, 2023. However, the day will remain working day in the country.

Weather in Caribbean

Summary of models and why a track slightly more west/south that puts more islands in direct impact is still very reasonable. Also Puerto Rico and Virgin Islands may have to deal with Tammy more directly and for longer if it does come more west.

The recon aircraft is finding the center slightly south of 13.5N and Tammy is staying west. This location is south and west of where the models and many of their ensembles had it in last night’s forecasts.

These model results were used to make the recent track forecasts so the new model runs this morning will have the new data and likely will shift a bit more west closer to those ensemble tracks which were more south and west.

The hurricane models like HAFS-A & HAFS-B, UKMET show this more south and west track then slow down north of Puerto Rico.

The GFS and Euro(ECENS) are different and many of their tracks take Tammy more east and north much faster. But a fair number of their tracks take the south and west track and slow down north of Puerto Rico.

These more southerly tracks are closer to the current location of Tammy east of Barbados(in other words their forecast from last night is closer to reality).

Canadian model ensemble tracks are more directly into the islands and slow down NW to N of Puerto Rico

COAMPS hurricane model tracks are more directly into the islands. Waiting to see if the new 11am does reflect any of the new model data or if the afternoon updates will reflect this. These small changes west could mean more impacts to islands like St. Lucia in central to north Windwards.

Track nudged slightly east. NHC says models came in slightly more east. Tammy has continued on a WNW 290 degree motion at slower 10mph. This caused the forecast to be slower, keeping Tammy affecting the islands longer. Rainfall totals were increased as well.

The low level and mid-level circulation is better aligned tonight as it slowed down to 10mph. This will give it a chance to strengthen. Already deep thunderstorms have popped up over the center last hour or so. This is seen on Barbados radar. To the south are large areas of moderate to strong thunderstorms.

There are some robust rainbands in there with lots of lightning in the ones east of Trinidad and Tobago. Some light to moderate rainbands are around Saint Lucia, St Vincent and near Barbados. The wind shear is less tonight and more convection is starting to gradually form in the previously drier western side of Tammy. This needs to be watched.

NHC thus raised its intensity forecast a bit making Tammy a solid category 1 as it passes near or over the Leewards. It is expected to be near 65-70mph as it nears Dominica and Guadeloupe.