weekly

Forecast Discussion

UPDATED: June-16-2026 8:21pm

Key Messages:

• Dry and warm conditions can persist as a ridge of high-pressure remains dominant over the Caribbean, keeping shower chances relatively low.
• Brief periods of showers are likely on Thursday and Sunday as a series of tropical waves traverses across the northwestern Caribbean.
  

Nowcast (Tonight):

Fair conditions would persist as a ridge of high-pressure remains the dominant weather pattern across the northwestern Caribbean, following a short rainy interlude due to a passing tropical wave this morning. Brief showers may occur overnight or during the early morning hours as some cloud can advected into the Cayman area from convective activity over Cuba.

Short Term Forecast (Wednesday through Friday):

During the day on Wednesday drier and more stable conditions would dominate during the daylight hours. Moderate southeasterly winds and seas would persist, though some fresh gusts are possible. 
Another fast-moving tropical wave should pass south of the Cayman area but can still supply a few cloudy spells with showers on Thursday, possibly during the evening and into Friday morning. Thunderstorm activity is possible as the GFS model suggests upper diffluence. Now, because the mid-levels may be quite dry, rainfall accumulations are not expected to be significant. 
Daytime temperatures are expected to maintain near the 90s°F, with heat indices near low 100s. 
As for the mid-levels, an easterly wind flow will persist. The tropical wave interacts with the Panamanian low and an intense mid-level low develops over the Nicaragua-Honduras area. 
An upper low near the Bahamas, should migrate south-westward, supporting strong north-northeasterly (upper-level) winds over the Cayman area through Thursday, and veering to south-south easterly from late Thursday. During this time, the upper levels are not supportive of any deep convection.  

Long Term Forecast (Saturday and Sunday):

A plume of dust is expected on Saturday, which may require a Dust Advisory. Another tropical wave, which can bring a few showers on Sunday morning with the low possibility of thunderstorms. However, the models do not agree upon the accumulation of rainfall, as there is a large variability as the GFS suggests upper-level convergence, as well as mid-level convergence, but the ECMWF suggests upper diffluence. 

Marine Forecast:

Moderate seas prevail through the period as winds remain moderate with fresh gusts at times as the ridge of high-pressure remains the dominant feature over the Caribbean. During the occurrence of thunderstorm activity, sea conditions can become quite choppy.

Forecaster: Wellington