Show Selection: |
#979759 (Received by flhurricane at: 4:36 AM 28.Aug.2019) TCDAT1 Tropical Storm Erin Discussion Number 7 NWS National Hurricane Center Miami FL AL062019 500 AM EDT Wed Aug 28 2019 GOES-16 shortwave infrared imagery and recent microwave overpasses show that Erin`s surface center has once again become exposed to the north of a rather amorphous deep convective mass. Erin`s severely tilted structure is in response to persistent moderate west-northwesterly shear, indicated in the UW-CIMSS shear product. Subjective satellite intensity estimates from TAFB and SAB support maintaining an initial intensity of 35 kt for this advisory. A series of microwave images during the past several hours indicate that the initial motion is estimated to be north-northwestward, or 330/5 kt, within the mid-level southerly flow produced by a mid-latitude shortwave trough approaching the northeastern United States, and the Bermuda high to east-southeast. A turn toward the north while accelerating is forecast later today and Erin is expected to reach Nova Scotia, with a north-northeastward heading, by the end of the week. Only a minor adjustment, a bit slower than the previous advisory, was made in order to hedge closer to the TVCA multi-model consensus. Statistical-dynamical intensity guidance show that the shear should diminish somewhat today while the system remains over warm oceanic sea surface temperatures. This, should allow for some slight strengthening at that time. Thereafter, baroclinic processes associated with the aforementioned mid-latitude trough and significantly decreasing sea surface temperatures should cause Erin to acquire extratropical characteristics, and complete the transition in 36 hours, as the Florida State Cyclone Phase Evolution forecast and global models unanimously predict. Minor adjustments were made to the forecast wind radii based on the RVCN consensus radii model. FORECAST POSITIONS AND MAX WINDS INIT 28/0900Z 32.4N 72.3W 35 KT 40 MPH 12H 28/1800Z 33.9N 72.2W 40 KT 45 MPH 24H 29/0600Z 36.6N 70.8W 35 KT 40 MPH 36H 29/1800Z 40.7N 67.8W 35 KT 40 MPH...POST-TROP/EXTRATROP 48H 30/0600Z 45.3N 63.9W 30 KT 35 MPH...POST-TROP/EXTRATROP 72H 31/0600Z...DISSIPATED $$ Forecaster Roberts |