Invest 92L

Invest 92L is located near 45N-25.5W moving quasi-stationary. Estimated surface winds are near 35 knots with a minimum central pressure near 1000 millibars. This morning satellite imagery showed a well-define circulation but with little associated deep convection. There is evidence of slight weakening as the winds have dropped, pressure has risen and ST numbers are down from 3.0 to 2.5. The disturbance is moving within a weak steering environment due to the upper trough it is embedded within, but should start moving towards the east over the next 24-48 hrs. Despite low vertical shear, the system continues to move over 16-18C waters and will likely weaken as it heads east. The storm will continued be monitored until then.

There is still some debate over whether 92L was a subtropical storm or not yesterday, June 2. The system had clusters of organize deep convection near its center of circulation with the highest winds, 45 knots, also found near its center. Subtropical numbers from the Satellite Service Division peaked at ST 3.0 (45 knots) yesterday which is derived from analyzing subtropical cloud patterns seen on satellite imagery. Finally, probably the most striking peace of evidence was the warm-core seen on microwave imagery from AMSU, which indicated tropical characteristics. Here we clearly see a subtropical storm but Invest 92L was moving over waters near 16C and the NHC states average sea surface temperature that helps lead to subtropical cyclogenesis is 24C (75F). In every tropical weather outlook they stressed the point of the sea surface temperatures and was probably the likely cause for the lack of classification.

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Gulf of Mexico

Broad mid-upper level flow covers the central Gulf of Mexico and is helping to generate scattered showers and thunderstorms across the region. While there has been evidence of some surface reflection south of Louisiana over the past 12 hrs this system remains in an environment unfavorable for tropical cyclogenesis. In addition the models show this system developing as a non tropical entity along the US Gulf Coast and moving northeast across the SE United States. The area will continue to be monitored. Regardless of development, heavy rains are expected over the northern Gulf coast from central Louisiana to the Florida Panhandle.

Elsewhere

Much of the global models continue to show enhanced vorticity over the SW Caribbean over the upcoming days and the GFS, NOGAPS and ECMWF develop a low pressure area somewhere in the Western Caribbean between 3-6 days. Despite the models having an inconsistent date and point of formation, vertical shear is expected to be favorable in that part of region. The ECMWF has the strongest solution around the next MJO upward pulse. This will be monitored.

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