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#1110987 (Received by flhurricane at: 4:39 PM 07.Oct.2022) TCDAT3 Tropical Storm Julia Discussion Number 6 NWS National Hurricane Center Miami FL AL132022 500 PM EDT Fri Oct 07 2022 Julia`s low-level center has been exposed for much of the day, after the burst of deep convection from this morning was stripped away by northerly shear. Convective cells have been regenerating in the proximity of the center, but much of the activity still lacks organization due to the shear. This morning`s Air Force Reserve reconnaissance mission measured a peak 925-mb flight-level wind of 50 kt, which reduces to an intensity between 35 and 40 kt. Given that the pressure did not drop, and the convection has not increased in organization, the initial intensity remains 35 kt. Julia has gained some latitude today, but overall it`s moving quickly toward the west, or 280/16 kt, to the south of strong mid-level ridging. The storm has been moving a little faster than was forecast during the past day or so, and global model guidance suggests that the current speeds should be maintained for the next 12-24 hours. Some deceleration is expected as Julia approaches the coast of Nicaragua, but because the storm has been moving faster than expected, it`s now forecast to reach the coast of Nicaragua early Sunday morning. The updated NHC prediction lies very near or along this morning`s forecast, but it`s just a little faster to account for recent models trends. Shear guidance from SHIPS and the GFS insists that the north-northwesterly shear affecting Julia should abate soon, or at least take on a more easterly component during the next day or so, which should favor more intensification. Ocean waters will also be plenty warm, and upper-level divergence over the system may increase as well. The NHC intensity forecast most closely follows a blend of the SHIPS guidance and the HCCA consensus aid, showing Julia reaching hurricane strength by 36 hours, about the time it passes the Colombian islands offshore of Nicaragua. Even though 65 kt is the peak intensity shown in the forecast, additional strengthening beyond that value is possible before Julia reaches the coast of Nicaragua. Julia is now expected to dissipate over Central America by Monday (72 hours). Various model solutions depict Julia`s leftover vorticity moving over the eastern Pacific waters, over the Bay of Campeche, or both after that time, but it is unclear at this time if that will lead to genesis of a new tropical cyclone. We`ll continue to monitor model trends and update the forecast as needed. Regardless of new development, the set up is likely to lead to heavy rains over Central America for several days, which could cause life-threatening flash floods and mudslides, especially in areas of mountainous terrain. Key Messages: 1. Julia is forecast to strengthen into a hurricane by Saturday evening or Saturday night while it moves over the southwestern Caribbean Sea, and a Hurricane Warning is in effect for portions of the Nicaragua coast and the offshore Colombian islands. Hurricane-force winds and a dangerous storm surge are expected in areas where the core of the system crosses the islands and moves onshore in Nicaragua. 2. Life-threatening flash flooding and mudslides are expected across portions of Central America this weekend. FORECAST POSITIONS AND MAX WINDS INIT 07/2100Z 13.0N 74.7W 35 KT 40 MPH 12H 08/0600Z 13.1N 77.3W 45 KT 50 MPH 24H 08/1800Z 13.0N 80.1W 55 KT 65 MPH 36H 09/0600Z 13.0N 82.5W 65 KT 75 MPH 48H 09/1800Z 13.2N 85.0W 50 KT 60 MPH...INLAND 60H 10/0600Z 13.5N 87.5W 30 KT 35 MPH...INLAND 72H 10/1800Z 14.3N 89.8W 25 KT 30 MPH...POST-TROP/INLAND 96H 11/1800Z...DISSIPATED $$ Forecaster Berg |