Good day all!
The area of low pressure I had been monitoring off of Melbourne FL., has regenerated and is classified as Tropical Depression Dorian. As of the 5:00 a.m. advisory, the following was available from the NHC.
5:00 AM AST Sat Aug 3
Location: 28.7°N 79.2°W
Moving: N at 6 mph
Min pressure: 1013 mb / 29.91 in.
Max sustained: 35 mph
Satellite loop imagery indicates the LLC has become decoupled from the deep convection, which is located south of the LLC.
This has occurred due to a slight increase of wind shear, which appears to be most significant at just above the 500 mb level, as mid shear values are fairly low to non existent, albeit this could be an erroneous reading, given the fact the 500 mb vorticity is well displaced from the 850 mb vorticity.
Based on the forecast wind shear pattern from the GFS shear maps, wind shear is forecast to increase significantly in about 12 hours. Based on this, I am not looking for any strengthening of the depression. In fact, albeit not my call, I would not even be issuing tropical cyclone advisories on this, as it has since lost the criteria classified for a tropical cyclone.
This system is currently moving slowly to the NE, and I expect to motion to continue for the next 24-36 hours. Based on forecast steering, and current satellite motion and position, I concur with the 06Z Dynamic Model guidance TVCC/TVCN track, however I am to the left, as Dorian is currently left of the forecast track positions.
I will continue to monitor Dorian on and off this weekend, but am not expecting anything significant to occur with him.
Elsewhere, albeit the GFS 06Z run has dropped cyclogenesis in the SW Caribbean in about 8-10 days, I will be monitoring the area for possible development, based on a significant lowering of pressures as seen in the NCEP 500 mb anomaly departure maps, and the probability shown in the NCEP Ensemble guidance.
I am not as concerned at the moment about the EATL wave I was tracking the other day, as the low associated with this appears to be laden with dry air and appears fairly stable. Convection is confined to the ITCZ in the CATL.
Have a blessed weekend!
T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST
MEMBER WEST CENTRAL FL AMS
CERTIFIED SKYWARN OFFICIAL STORM SPOTTER (advanced)