Disturbances Bring Heavy Rain Threat to Parts of the Caribbean

No tropical issues for the mainland U.S. in the week ahead

Two disturbances we’ve been tracking this week – one in the western Caribbean and the other passing just north of Puerto Rico and the U.S. Virgin Islands today – will bring the threat of heavy rainfall to Central America and the Greater Antilles but neither will be a concern for the mainland U.S.

The easternmost disturbance – designated Invest 94L – is accompanied by a pouch of blustery weather, and while the worst weather will move just north of the U.S. Virgin Islands and Puerto Rico today, the system will usher in rich tropical air and enhance the heavy rain and flood threat for the islands into the weekend.

The runway for 94L is short and by late weekend it will get dismantled by a wall of wind shear. Though development is unlikely, the heavy rain threat will persist for parts of Haiti, the Dominican Republic, and eastern Cuba into early next week.

Narrow development window in the western Caribbean

Meanwhile in the western Caribbean a large area of storminess associated with a sprawling area of low pressure will be moving inland across Central America and southern Mexico this weekend. The low-pressure area – now designated Invest 95L near the northern coast of Honduras – is slightly better organized today, but thunderstorms remain disorganized.

Total rainfall forecast across Central America through next Tuesday, October 22^nd from the European forecast model. Models show widespread totals of 6-12 inches (150-300 mm), with localized amounts approaching 18 inches (450 mm) or more across parts of southern Mexico. Credit: Pivotal Weather

There’s a narrow window for a short-lived tropical depression to form before the system moves inland tomorrow. Regardless, heavy rainfall leading to a widespread flood threat is the upshot for northern Honduras, Belize, Guatemala, and southern Mexico into the first part of next week.

No new candidates for now

As we discussed in yesterday’s newsletter, the Atlantic should quiet down noticeably next week.

Forecast low-pressure tracks through the end of October from the European model ensemble system showing very little activity in the Atlantic behind the two systems we’re tracking today. As we discussed in yesterday’s newsletter, the Atlantic will remain in a suppressed phase until around the first week of November. Credit: Weathermodels.com

By late October, the number of tropical waves leaving Africa drops off considerably as the west African monsoon retreats southward toward the equator for the winter months.

We continue to watch for mischief along stalled fronts or activity within the Central American Gyre like we’re seeing today in the western Caribbean. For now at least the fall fronts are moving which means we’ll stay shielded from tropical trouble for the foreseeable future.