MSEAS Probabilistic Forecasts of LC Separation (Issued 29 Jun 2025)

This MIT-MSEAS PE ensemble forecast contains 195 realizations.

To define eddies, we used the 17 cm de-tided SSH contour in the deeper Gulf [Dukhovskoy et al., 2015]. Hence, for reach realization, we de-tide the SSH field and de-mean it over the region north of 22°N, west of 81.5°W, and deeper than 200 m (i.e., considering only the deep waters in the Gulf). We then extract the 17 cm contours of the resulting field, highlighting the locations of the LC and LCEs. To identify possible new LCE separation, we eliminate eddy remnants in the western Gulf by restricting to the region between 22.5°N and 27.5°N and between 89°W and 83°W. If a closed contour with an arclength of at least 200 km is fully contained in this region, this can indicate LCE detachment. We finally examine these realizations and count the number of LCE detachments.

• On June 29, 70 realizations show LCE separation, 125 show no LCE separation
• On July 2, 51 realizations show LCE separation, 144 show no LCE separation
• On July 5, 2 realizations show LCE separation, 193 show no LCE separation

Date	Number of separations	All separated realizations	All unseparated realizations	Example separated realization	Example unseparated realization
20250629	70
20250702	51
20250705	2