Weekly Synopsis

Forecast Discussion

UPDATED:  26 July 2026 6:55 p.m.

KEY MESSAGES:

• Dry air expected in the region, reducing precipitation probabilities.
• Light and variable winds may promote localized afternoon showers and possible thunder this week.
• Tropical wave on late Monday but may be without much impact.
• Mainly smooth to slight seas, becoming moderate by the end of the week.

Nowcast (Tonight):

A weak ridge is present over the northwestern Caribbean, and a slack pressure gradient is supporting light and variable winds and smooth seas. A tropical wave is analyzed to the south and west of the Cayman area, with the moisture signature also to the south of our area. Mid and upper-level cloud can be observed on Satellite imagery associated with this signature. This tropical wave had very little impact on the Cayman Islands today. An upper low is present to the south of Cuba and drifting over the Cayman area, promoting sinking air over the area tonight. Thus, deep convection is not expected, but cloud drift from Cuba with the northeaster wind-flow may result in some overnight or early morning showers over the Sister Islands. Rainfall accumulation should be negligible.

Short Term Forecast  (Monday through Wednesday):
A slack pressure gradient is resulting in light and variable winds. These light winds coupled with daytime heating may lead to afternoon showers and the possible isolated thunderstorm. However, the dry air, currently over the central Caribbean may not provide sufficient moisture for sustained deep convection, as this dry air with some light dust, may drift over the Cayman area. 
However, there is also a tropical wave that is expected to pass across the lower western Caribbean late Monday or early Tuesday. Though there may be some moisture intrusion into the dry air, this moisture may be concentrated closer to Central America. Any influence in the Cayman area may not support sustained deep convection. Also, the upper-level low would continue to drift over the Cayman area, moving southwestward, providing upper convergence which would not support upward vertical motion. Rainfall accumulation is not expected to be more than 2 mm.
Mild dust may be present late Tuesday, and drier conditions should re-establish by Wednesday.
A shortwave in the upper level can provide some support for rising air, but, with a dry atmosphere, precipitation is not expected to amount to much.   

Extended Forecast  (Thursday and Friday):

The presence of boundary layer moisture, light, easterly winds, coupled with daytime heating can result in isolated afternoon showers. The mostly dry air in the mid-levels can hinder sustained convection. With a deeper look at what can happen in the atmosphere, the wind-flow at the mid-levels can bring some increase in moisture from the south of the area, if there is moisture to be advected, and the upper-levels can provide support for deep convection. So, here is the possibility of the isolated thunderstorm, if the conditions are right. 
Now, if the Atlantic high-pressure system builds as is forecast, then the winds can strengthen, providing atmospheric aeration. In some cases, convection can be enhanced with frictional convergence, or inhibited by said aeration, depending on the depth and strength of the winds on Friday.  With this much to consider, the medium chance of showers can be maintained. 

Marine Forecast:

Smooth seas on Monday and Tuesday gradually become slight on Wednesday and moderate on Thursday and Friday. This increase in wave heights follows the pressure gradient tightening briefly over the western Caribbean as Atlantic high-pressure system gradually builds. Heavy showers and thunderstorms occurring offshore can produce choppy sea conditions.  

Forecasters
Wellington