National Hurricane Center Monitoring Two Systems, Additional Waves
BY: WEATHER TEAM | BocaNewsNow.com
BOCA RATON, FL (BocaNewsNow.com) (Copyright © 2023 MetroDesk Media, LLC) — The National Hurricane Center Friday is monitoring Tropical Storm Bret, Tropical Storm Cindy, and multiple tropical waves in the Atlantic, Caribbean and Gulf. None are expected to impact the United States mainland — at least for now.
We start with the Tropical Storm Cindy update:
Cindy is continuing to show signs of improvement based on satellite imagery. Deep convection with cold cloud tops of less than -80 degrees C are near the estimated low-level center, an indication the vertical wind shear is likely weakening. The initial intensity has been increased to 40 kt based on a blend of the 3.0 and 2.5 subjective Dvorak satellite intensity estimates from TAFB and SAB, respectively.
The reasoning behind the intensity forecast is unchanged. SHIPS model guidance indicates that Cindy will remain embedded within an area of weak vertical wind shear for the next day or so, shielding it from the surrounding drier mid-level airmass. Given the relatively conducive environmental and oceanic conditions, gradual strengthening is expected. Beyond 48 h, the deep-layer shear is forecast to increased which, in combination with the dry air, will likely weaken Cindy early next week. The official intensity forecast is very similar to the previous prediction.
Cindy is moving west-northwestward at 13 kt. This motion is expected to continue during the next several days as Cindy moves around the southwest periphery of a subtropical ridge. The track guidance for the cyclone has shifted northward in the 3-5 day range, and the NHC track forecast has been nudged northward as a result. This track still keeps Cindy well to the northeast of the northern Leeward Islands.
FORECAST POSITIONS AND MAX WINDS
INIT 23/0900Z 12.1N 46.9W 40 KT 45 MPH
12H 23/1800Z 12.9N 48.7W 45 KT 50 MPH
24H 24/0600Z 14.3N 51.2W 50 KT 60 MPH
36H 24/1800Z 16.0N 53.9W 50 KT 60 MPH
48H 25/0600Z 17.7N 56.5W 50 KT 60 MPH
60H 25/1800Z 19.4N 59.0W 45 KT 50 MPH
72H 26/0600Z 20.9N 61.4W 40 KT 45 MPH
96H 27/0600Z 23.5N 65.0W 35 KT 40 MPH
120H 28/0600Z 25.7N 67.3W 30 KT 35 MPH…POST-TROP/REMNT LOW
This is the Tropical Storm Bret update:
Bret’s center is now over the southeastern Caribbean Sea, but convective activity extends more than 300 n mi to the east across the Windward Islands and adjacent Atlantic waters. An Air Force Reserve Hurricane Hunter aircraft measured peak 850-mb flight-level winds of 60 kt and SFMR winds of 49 kt to the north of the center on its last pass before heading back to base, and the initial intensity is therefore maintained at 50 kt. The plane had found that Bret’s central pressure had dropped again, back down to 1001 mb.
Bret continues to move quickly westward, or 270/16 kt, to the south of an area of high pressure located over the western Atlantic. The subtropical ridge is expected to continue steering Bret quickly westward across the eastern and central Caribbean Sea during the next couple of days. There are no changes to the track model guidance, or the track forecast reasoning, and the official NHC forecast is a little faster than the model consensus aids, hedging toward the GFS and ECMWF solutions.
Bret is approaching an upper-level trough located over the eastern Caribbean Sea, and the resulting deep-layer shear over the storm is analyzed to be about 25 kt out of the west-southwest. Even stronger shear and a dry mid-level environment are expected to cause Bret to gradually weaken during the next couple of days, with global model fields showing the system degenerating into a trough over the central Caribbean Sea some time over the weekend. The NHC forecast shows dissipation by Sunday, but some model fields suggest it could happen earlier than that.
KEY MESSAGES:
- Bret is moving westward over the southeastern Caribbean Sea, but trailing rainbands with embedded gusty winds continue to affect portions of the Windward Islands. These conditions should gradually subside through the day.
- A Tropical Storm Warning remains in effect for St. Vincent and the Grenadines, St. Lucia, and Martinique.
FORECAST POSITIONS AND MAX WINDS
INIT 23/0900Z 13.4N 62.9W 50 KT 60 MPH
12H 23/1800Z 13.6N 65.2W 45 KT 50 MPH
24H 24/0600Z 13.8N 68.6W 40 KT 45 MPH
36H 24/1800Z 13.9N 72.1W 35 KT 40 MPH
48H 25/0600Z 13.9N 75.6W 30 KT 35 MPH
60H 25/1800Z…DISSIPATED
