An area of deep thunderstorm activity now occurring over the southwestern Caribbean is expected to push west-northwest to northwestward this week reaching the northwestern Caribbean by late Tuesday into Wednesday and then the Bay of Campeche by around Thursday or Friday. This system is then forecast to move into the western Gulf of Mexico this weekend where it will need to be watched for possible tropical development.

This activity is being caused by the Monsoon trough interacting with a westward moving tropical wave now located over the central Caribbean. This particular tropical wave which is now located along 71 West Longitude will help to sustain the thunderstorm activity that is occurring over the southwestern Caribbean now.

The reason why we aren’t seeing any sort of tropical development from the southwestern Caribbean disturbance is due to strong wind shear on the order of 30-50 knots which is leading to a very unfavorable environment for development across not only the Caribbean, but also across much of the Gulf of Mexico. The question is whether this very strong wind shear will persist throughout the next week and thus stop any development from occurring or will we see a more favorable environment develop leading to the possibility for tropical development later this week or this weekend in the western Gulf of Mexico.

Here Are My Thoughts: First things first, I still think that we will see tropical development starting in the Bay of Campeche around Friday and then spreading into the western Gulf of Mexico this weekend. Any possible tropical development has the potential to impact areas from northern Mexico northward through the Texas and Louisiana coasts.

Based on everything that I have looked at, I think that there is a 30 percent chance for tropical development in either the Bay Of Campeche around Friday or the Western Gulf Of Mexico between Saturday and Sunday.

There already is quite a bit of thunderstorm activity occurring over the southwestern Caribbean as the westward moving tropical wave near 71 West Longitude is providing a “trigger” to get things going. Large Monsoonal low pressure systems like we are going to have are not only always very difficult to forecast in terms of whether they are going to develop or not, but they are often slow to develop.

Crown Weather Services

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

1. A broad area of showers and thunderstorms has persisted over the southwestern Caribbean Sea for the past several hours. This activity is associated with a tropical wave over northwestern Venezuela and a surface trough located just east of Nicaragua interacting with a large upper-level trough. Little development of this area of disturbed weather is expected over the next few days due to interaction with Central America and the Yucatan Peninsula. However, environmental conditions could become somewhat more conducive for some limited development when the system moves into the southwestern Gulf of Mexico by the end of the week. Regardless of development, this disturbance will produce locally heavy rainfall across portions of Nicaragua, Honduras, Belize, Guatemala, and the Yucatan Peninsula through Thursday.

* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...20 percent.

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Mon Jun 11 2018

Flooding rain to eye Central America to Texas regardless of tropical storm potential in Gulf, Caribbean

An area of disturbed weather in the western Caribbean Sea may cause flooding problems along its path to the Gulf of Mexico despite a small chance to organize into a weak tropical system this weekend.

A broad area of drenching showers and strong thunderstorms is forecast to drift northwestward from the western Caribbean to the western Gulf of Mexico over the next five to seven days.

Development seems unlikely over the next few days and may not occur at all, despite sufficiently warm waters, according to AccuWeather Hurricane Expert Dan Kottlowski.

A non-tropical storm in the vicinity will create substantial wind shear from Central America and the western Caribbean to Mexico's Yucatan Peninsula.

Wind shear is the variation of wind speed and direction at different levels of the atmosphere. When wind shear is strong as it is now, it prevents a circulation from developing just above the surface of the ocean.

There is a small chance of development from the west-central Gulf of Mexico late this week to near the Texas and southwestern Louisiana coast this weekend.

"In order for development to occur, wind shear would have to diminish," Kottlowski said.

Impact from the disturbance and non-tropical storm

The same non-tropical storm will pump moisture across Central America, Cuba and the Florida Keys.

Thunderstorms over Cuba and the Keys are likely to be spotty in nature, although clouds will be noticeable at times.

Regardless of development into a named tropical system or not, drenching downpours and gusty thunderstorms are also in store close to the disturbance's path as it moves northwestward.

The disturbance may enhance the downpours enough to cause flash flooding.

During the middle days of the week, the potential for isolated flash flooding and mudslides will extend from Nicaragua to Honduras, Belize, Guatemala and southeastern Mexico.

Accuweather

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For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

200 PM EDT Tue Jun 12 2018

A large area of showers and thunderstorms located over the western Caribbean Sea just to the east of Nicaragua and northeastern Honduras is associated with a sharp surface trough. This area of disturbed weather is forecast to move westward to northwestward over Central America and the Yucatan Peninsula during the next couple of days, and little development is expected during that time due to strong upper-level winds. However, environmental conditions could become slightly more conducive for some development when the system moves into the southwestern Gulf of Mexico by the end of the week. Regardless of development, this disturbance will likely produce locally heavy rainfall across portions of Nicaragua, Honduras, Belize, Guatemala, and the Yucatan Peninsula through Thursday.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...20 percent.

200 AM EDT Wed Jun 13 2018

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Disorganized showers and thunderstorms over the western Caribbean
Sea are associated with a weak surface trough. This activity is
forecast to move westward to northwestward over Central America and
the Yucatan Peninsula during the next couple of days with no
significant development. Environmental conditions could become
slightly more conducive for some development if the system moves
into the southwestern Gulf of Mexico by the end of the week.

* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

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An area of disturbed weather in the western Caribbean Sea may cause flooding problems along its path to the Gulf of Mexico despite a small chance to organize into a weak tropical system this weekend.

A broad area of drenching showers and strong thunderstorms is forecast to drift northwestward from the western Caribbean to the western Gulf of Mexico over the next five days.

Development seems unlikely over the next couple of days and may not occur at all, despite sufficiently warm waters, according to AccuWeather Hurricane Expert Dan Kottlowski.

A non-tropical storm in the vicinity will create substantial wind shear from Central America and the western Caribbean to Mexico's Yucatan Peninsula.

Wind shear is the variation of wind speed and direction at different levels of the atmosphere. When wind shear is strong as it is now, it prevents a circulation from developing just above the surface of the ocean.

During the middle days of the week, the potential for isolated flash flooding and mudslides will extend from The Cayman Islands, Jamaica, Nicaragua to Honduras, Belize, Guatemala and southeastern Mexico.



Accuweather

NWS National Hurricane Center
200 PM EDT Wed Jun 13 2018

Disorganized showers and thunderstorms over the northwestern Caribbean Sea are associated with a surface trough. This area of disturbed weather, accompanied by strong gusty winds, is forecast to move west-northwestward over Belize and the Yucatan Peninsula later tonight, and move into the southwestern Gulf of Mexico by Thursday afternoon. No development is expected for the next day or so due to land interaction with the Yucatan Peninsula and strong upper-level winds.