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| #1009452 (Received by flhurricane at: 4:48 PM 24.Jul.2020) TCDAT2 Tropical Storm Gonzalo Discussion Number 13 NWS National Hurricane Center Miami FL AL072020 500 PM AST Fri Jul 24 2020 An Air Force Reserve Hurricane Hunter aircraft investigated Gonzalo earlier this afternoon and found it to very poorly organized. The aircraft even reported seeing multiple low-level swirls which is surprising given the small size of the cyclone. The highest flight-level winds measured by the plane were 41 kt while the highest believable SFMR values were right around 35 kt. Based on that data, Gonzalo`s intensity has been lowered to 35 kt. Small systems like Gonzalo are notorious for quick changes in structure and intensity, both up and down. Therefore, despite its current downswing, it is too soon to say for sure that Gonzalo will not restrengthen to some degree before it reaches the southern Windward Islands. That said, confidence in the intensity forecast is a little higher now that we have better data to base the forecast on and it does not seem likely that Gonzalo will overcome the dry air that is currently inhibiting its development. Given the current structure of the tropical storm, the NHC intensity forecast has been lowered significantly, but still allows for some slight restrengthening during the next 24 h. The new forecast is much closer to the intensity consensus, below only the HWRF model which does not appear to have a realistic initialization. Once Gonzalo reaches the eastern Caribbean, weakening is anticipated and the cyclone is forecast to dissipate within 3 days, if not sooner. Gonzalo has sped westward all day with a motion near 270/16 kt. The guidance continues to insist that Gonzalo will gain a little latitude in the near future, and a general westward to west-northwestward motion is still forecast for the next few days. The NHC track forecast has again been shifted southward, but now lies near the middle of the guidance envelope and very near the various track consensus aids. Key Messages 1. Gonzalo is forecast to bring tropical storm conditions across portions of the southern Windward Islands Saturday and Saturday night. Tropical Storm Warnings are currently in effect for some of the islands. Interests in the southern Windward Islands should monitor the progress of Gonzalo and follow any advice given by local officials. 2. Gonzalo is expected to produce heavy rain over portions of the southern Windward Islands. This could lead to life-threatening flash flooding. FORECAST POSITIONS AND MAX WINDS INIT 24/2100Z 10.0N 55.6W 35 KT 40 MPH 12H 25/0600Z 10.4N 58.0W 40 KT 45 MPH 24H 25/1800Z 11.4N 61.1W 40 KT 45 MPH 36H 26/0600Z 12.2N 64.2W 40 KT 45 MPH 48H 26/1800Z 13.1N 67.9W 35 KT 40 MPH 60H 27/0600Z 13.4N 71.1W 30 KT 35 MPH 72H 27/1800Z...DISSIPATED $$ Forecaster Zelinsky |