|
Show Selection: |
| #981025 (Received by flhurricane at: 10:45 PM 04.Sep.2019) TCDAT3 Tropical Storm Gabrielle Discussion Number 6 NWS National Hurricane Center Miami FL AL082019 1100 PM AST Wed Sep 04 2019 South to southwesterly shear is affecting the overall organization of Gabrielle this evening. A recent scatterometer pass indicated that the low-level center was located on the southern edge of weakening convection, and to the south of a mid-level circulation apparent in infrared satellite imagery. This same scatterometer pass showed an expanded wind field in the northwest quadrant as well as 45-kt peak winds, and this initial intensity is in agreement with the latest subjective satellite intensity estimate from TAFB. The shear is not expected to abate for the next 48 hours, and sea surface temperatures are forecast to remain marginal through 36 hours. Therefore little to no change in intensity is expected from Gabrielle during the next couple of days. After 48 hours, shear is expected to decrease for a few days while the cyclone moves over waters warmer than 28 C. This should allow for some gradual intensification, and Gabrielle is forecast to become a hurricane by Sunday. The official intensity forecast is close to the previous one and very near the intensity from the corrected consensus HCCA. Gabrielle has been moving northwestward or 325/6 kt. This motion should continue for the next day or so as the cyclone is steered by a subtropical ridge to its northeast. After that time, a mid- to upper-level low is forecast to develop to the west of Gabrielle, which will help to increase the forward motion late this week and over the weekend. There was a notable westward shift in the guidance beyond 72 hours possibly due to the interaction of the cyclone with the aforementioned upper low. After 96 hours, an approaching mid-latitude trough will begin to turn Gabrielle to the north then northeast. The official forecast track is very similar to the previous one through 72 hours, and was shifted slightly westward thereafter. FORECAST POSITIONS AND MAX WINDS INIT 05/0300Z 21.5N 34.4W 45 KT 50 MPH 12H 05/1200Z 22.4N 35.2W 45 KT 50 MPH 24H 06/0000Z 23.7N 36.6W 45 KT 50 MPH 36H 06/1200Z 25.4N 38.3W 45 KT 50 MPH 48H 07/0000Z 27.3N 40.2W 45 KT 50 MPH 72H 08/0000Z 30.8N 44.6W 55 KT 65 MPH 96H 09/0000Z 34.0N 48.0W 65 KT 75 MPH 120H 10/0000Z 37.5N 48.0W 65 KT 75 MPH $$ Forecaster Latto |