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| #1143890 (Received by flhurricane at: 4:41 AM 16.Jul.2023) TCDAT5 Subtropical Storm Don Discussion Number 9 NWS National Hurricane Center Miami FL AL052023 500 AM AST Sun Jul 16 2023 Don is barely a subtropical storm. As mentioned in the previous discussion, the ASCAT-C pass from around 00Z showed peak winds near 35 kt in a small area about 60 n mi east-northeast of the center. Deep convection is limited to the same region where the strongest winds were observed. The initial intensity remains 35 kt for this advisory based on the earlier ASCAT data and a blend of the latest satellite intensity estimates that range from 25 to 45 kt. The storm is currently over cool 24 degree C waters and the sea surface temperatures along the expected track over the next day or two are about a degree lower. These unfavorable oceanic conditions combined with dry air that continues to wrap into the circulation should cause Don to remain poorly organized. If the storm does manage to survive beyond 48-72 hours, the water temperatures are expected to increase a little along the forecast track, which could cause some increase in thunderstorm activity. Nonetheless, significant strengthening is not expected due to continued dry air entrainment and an increase in wind shear. The NHC intensity forecast is similar to the previous one and shows Don remaining a weak system through the forecast period. However, even though not explicitly forecast, it would not be surprising if Don becomes a remnant low at some point in the next couple of days. Don is gradually bending to the right and an eastward motion is expected later today as high pressure builds over the eastern Atlantic. A turn to the southeast is expected on Monday followed by a southward motion as the ridge shifts westward and a trough becomes established over the northeastern Atlantic. Don could stall or loop around during the middle part of the weak as the steering currents collapse. The model guidance has not changed much, and the NHC track forecast generally follows the various consensus models. FORECAST POSITIONS AND MAX WINDS INIT 16/0900Z 38.6N 48.4W 35 KT 40 MPH 12H 16/1800Z 39.3N 47.6W 35 KT 40 MPH 24H 17/0600Z 39.4N 45.6W 30 KT 35 MPH 36H 17/1800Z 38.6N 43.5W 30 KT 35 MPH 48H 18/0600Z 37.2N 41.8W 30 KT 35 MPH 60H 18/1800Z 35.8N 41.2W 30 KT 35 MPH 72H 19/0600Z 34.3N 41.3W 30 KT 35 MPH 96H 20/0600Z 32.8N 42.6W 35 KT 40 MPH 120H 21/0600Z 33.6N 44.7W 35 KT 40 MPH $$ Forecaster Cangialosi |
