000 WTNT42 KNHC 030833 TCDAT2 Hurricane Larry Discussion Number 11 NWS National Hurricane Center Miami FL AL122021 500 AM AST Fri Sep 03 2021 Larry continues to gradually become better organized. Satellite images show a fairly compact central dense overcast feature with an eye occasionally evident. Beyond the inner core, banding features are gradually becoming more distinct, especially to the south of the center. The latest Dvorak classifications at 0600 UTC was 4.5/77 kt from TAFB and SAB, and based on those estimates and the improving trend, the initial intensity is nudged upward to 80 kt. Larry is moving west-northwestward at 17 kt. There has been no change to the track forecast reasoning. A continued westward to west-northwestward motion is expected on Friday and through the weekend as the hurricane remains on the south side of a mid-level ridge. By early next week, Larry is expected to slow down and turn northwestward when it reaches the southwestern periphery of the ridge. The models are in fairly good agreement, and the NHC track forecast lies near the middle of the guidance envelope. This forecast is largely an update of the previous one. The environmental factors appear favorable for steady strengthening during the next few days with wind shear remaining low and mid-level moisture fairly high. The only slightly negative factor is marginally warm 26-27 deg C waters that Larry will be moving over during the next couple of days, which should prevent rapid intensification. All of the models are in general agreement that Larry will become a major hurricane in a day or so with continued strengthening through day 3, and the NHC intensity forecast follows suit. Some weakening is shown by the end of the forecast period when the wind shear could increase a little. This forecast is very similar to the previous one and lies near the high end of the guidance envelope. It should be noted that eyewall replacement cycles are possible, which could cause intensity fluctuations that are challenging to predict. The leading swell front from Larry is expected to reach the Lesser Antilles on Sunday, increasing the risk of life-threatening rip currents and high surf conditions on those islands early next week. Large swells are likely to spread to areas surrounding the western Atlantic later in the week as well. FORECAST POSITIONS AND MAX WINDS INIT 03/0900Z 14.6N 38.9W 80 KT 90 MPH 12H 03/1800Z 15.2N 41.1W 90 KT 105 MPH 24H 04/0600Z 16.2N 43.8W 100 KT 115 MPH 36H 04/1800Z 17.3N 46.2W 105 KT 120 MPH 48H 05/0600Z 18.6N 48.5W 115 KT 130 MPH 60H 05/1800Z 19.8N 50.5W 120 KT 140 MPH 72H 06/0600Z 21.1N 52.5W 120 KT 140 MPH 96H 07/0600Z 23.8N 55.8W 115 KT 130 MPH 120H 08/0600Z 27.1N 58.9W 110 KT 125 MPH $$ Forecaster Cangialosi