Tropical Low Brewing in the Caribbean Father’s Day Weekend

Chances continue to increase for a tropical low to develop in the Caribbean for Father’s Day weekend. The time-frame for any tropical formation is Sunday-Tuesday.

So the big question on everyone’s minds, will we have a tropical storm in the Gulf of Mexico?

Infrared Satellite of the northwestern Caribbean valid for 17:00Z.

The answer is much more complicated than a simple “yes” or “no”. Storminess is beginning to increase across the northwestern Caribbean, however a disturbance has not been detected yet and Wilkens Weather is not expecting tropical development over the next 24 hours. Several factors are analyzed when forecasting tropical weather including sea surface temperatures (SST), vertical wind shear, and tropical atmospheric moisture. The sea surface temperatures in the southern Gulf are around 28°C, indicating favorable conditions for development. Atmospheric moisture, explained in a previous blog here, surges into the southern Gulf this weekend providing ideal conditions for tropical development. The third and final key ingredient meteorologists are monitoring is vertical wind shear. Light winds are vital to sustain and strengthen the structure of tropical systems.

Wind Shear Friday.
Friday morning analysis of deep-layer wind shear across the Caribbean and Atlantic via CIMSS

Currently, there is 40 knots of wind shear across the northwest Caribbean prohibiting any tropical development. The GFS and ECMWF both hint at weakening wind shear over the weekend in the Caribbean, allowing for the possibility of a low pressure system to develop. As this disturbance slides west across the Yucatan Peninsula this weekend, it will begin to encounter strong wind shear across the Gulf of Mexico. However by Monday evening, the ECMWF model weakens wind shear to 15-20 knots across the southern Gulf supporting the possibility for tropical development. When analyzing wind shear and forecasting hurricanes, meteorologists typically look for 20 knots or less. Therefore, it’s very unlikely we will see any tropical system in the Gulf of Mexico until next week.

Once a low pressure system forms, we will have a much better idea of where this system will track. With three-five days out, models continue to differ on timing, strength, and track of this possible tropical low. Friday morning’s run of the U.S. GFS model is forecasting a broad low pushing into the northern Gulf Monday into Tuesday. However, the European ECMWF model has been fairly consistent on a westward track into the Bay of Campeche.

Another tropical wave, Invest 92L, is also in the spotlight as chances have increased for development over the past 24 hours. Invests, short for investigations, are disturbances with model tracking. In the Atlantic basin, these disturbances are labeled with an L and a given number 90-99. The National Hurricane Center is predicting a 30% chance for a tropical system to form over the next 48 hours. Initial tropical track guidance shows the wave nearing Trinidad and Tobago within 96 hours (4 days).

Track guidance.png

The largest threat for marine operations is tropical weather. As we’ve mentioned in our last blog, it’s important to remember that despite a tropical system forming, there is still a risk of hazardous winds and seas affecting marine operations.