Good evening everyone!
After some continued slow strengthening today, Tropical Storm Chantal now has maximum sustained winds of 65 MPH.
As of the 5:00 p.m. EDT advisory from the NHC, the following information was available on Chantal:
5:00 PM AST Tue Jul 9
Location: 15.2°N 63.7°W
Moving: WNW at 26 mph
Min pressure: 1006 mb / 29.71 in
Max sustained: 65 mph
NHC WATCHES AND WARNINGS
Satellite imagery this evening indicates Chantal has become fairly ragged, and this can be attributed to NWLY shear of about 15-20 knots at the moment. This is pretty much verified, as the storm is tilted toward the SE based on vorticity maps.
A combination of the wind shear, and Chantal’s fast forward speed will continue to pose a battle for the system as it continues to head toward Hispaniola.
Based on current motion in satellite imagery, and current steering, the forecast track for Chantal has initially shifted very slightly westward, and may put her crossing of Hispaniola, slightly south of the center of the Island.
However, based on the current run of the 12Z forecast steering layers maps (Valid 00Z tonight), even though I pretty much concur with the official forecast track, I prefer the track shape from the Bahamas, to point of landfall, of that between the TVCC / TVCN and AVNI Dynamic Model Guidance. Of course as fluctuations in storm strength, and steering occur, subtle changes to track will most likely occur between now and by the time the system reaches the Bahamas.
Based on this, and if nothing changes much, Tropical Storm Watches could go up for the Florida Peninsula, up to just north of the SC border as early as Fri. morning.
Based on the current wind shear product, and the last update of the Zonal Shear forecast, Chantal may only strengthen slightly more, and become a 70 mph Tropical Storm prior to crossing the Hispaniola coastline. Once she traverses Hispaniola, I do expect some disruption of the system, however with her fast forward speed, and small COC, she may not too much trouble recovering as she enters the Bahamas, especially with a slow down in forward motion. As steering becomes weak and she slows int he Bahamas, timing will depend on how strong she may become. Based on the Zonal Shear, the upper level environment becomes the most conducive prior to a second landfall in the SEUS. Based on the brief time frame, I concur with the NHC intensity forecast, albeit any further slowing just prior to landfall, or improvement of the upper level pattern, I would not rule out a 60 mph storm.
I will continue to monitor Chantal for any significant changes, and will have another update in the morning.
Elsewhere, the GFS has dropped the solution of developing Dorian next week. However, I will continue to monitor the EATL for any development during next week.
T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST
MEMBER WEST CENTRAL FL AMS
CERTIFIED SKYWARN OFFICIAL STORM SPOTTER (advanced)