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| #1155703 (Received by flhurricane at: 4:52 AM 03.Oct.2023) TCDAT2 Tropical Storm Philippe Discussion Number 40 NWS National Hurricane Center Miami FL AL172023 500 AM AST Tue Oct 03 2023 High clouds from a recent convective burst just southeast of Philippe`s center has obscured the low-level center for much of the night. However, surface observations and microwave imagery indicate that the center is still located near the northwestern edge of the large convective mass, and it is passing very near Anguilla in the northern Leeward Islands. Most of the stronger winds are located over the southern and southeastern portions of the circulation where a wind gust to 41 kt was reported on Antigua a few hours ago. The Leeward Islands are likely to experience strong gusty winds and heavy rains even as the center moves north of those islands this morning. The intensity of the cyclone remains 45 kt, based on earlier SFMR and dropwindsonde data from an Air Force Reserve reconnaissance aircraft. The next mission into Philippe is scheduled for later this morning. Philippe`s motion has been wobbling between west-northwest and northwest at about 7 kt. A more definitive northwestward heading is expected to begin today as Philippe moves around the western portion of a mid-level ridge over the central subtropical Atlantic. The storm`s motion should become north-northwestward to northward on Wednesday and Wednesday night as it moves between the ridge to its east and trough off the southeastern United States coast. By late in the forecast period, there is significant bifurcation in the track guidance with the GFS slowing the system down, while the ECMWF and UKMET show the cyclone moving quickly northward into Atlantic Canada ahead of a deep-layer trough. The GFS track appears to be an eastern outlier at this time. Thus, the NHC track forecast was shifted westward at days 4 and 5 to be closer to the multi-model consensus aids. Additional adjustments in the long-range track forecast may be required in subsequent advisories. Strong vertical shear is forecast to linger over Philippe during the next two to three days, and little change in strength is forecast during that time. The system could encounter a region of diffluent upper-level winds later in the period which could support some strengthening. The NHC intensity forecast shows a slightly lower peak than before as the intensity guidance and global models generally show less strengthening than before. KEY MESSAGES: 1. Tropical storm conditions are expected across Barbuda, Antigua, and Anguilla this morning. Strong gusty winds are also likely elsewhere in the Leeward Islands today. 2. Heavy rainfall from Philippe is expected to produce scattered flash flooding across portions of the Leeward and northern Windward Islands, particularly between Barbuda and Dominica, into early Wednesday. FORECAST POSITIONS AND MAX WINDS INIT 03/0900Z 18.5N 62.9W 45 KT 50 MPH 12H 03/1800Z 19.2N 63.4W 45 KT 50 MPH 24H 04/0600Z 20.6N 64.0W 45 KT 50 MPH 36H 04/1800Z 22.1N 64.4W 45 KT 50 MPH 48H 05/0600Z 23.9N 64.7W 45 KT 50 MPH 60H 05/1800Z 26.0N 64.6W 45 KT 50 MPH 72H 06/0600Z 28.3N 64.1W 50 KT 60 MPH 96H 07/0600Z 32.8N 62.3W 55 KT 65 MPH 120H 08/0600Z 38.5N 61.5W 55 KT 65 MPH $$ Forecaster Brown |
