|
Show Selection: |
| #1114091 (Received by flhurricane at: 5:09 PM 30.Oct.2022) TCDAT5 Potential Tropical Cyclone Fifteen Discussion Number 1 NWS National Hurricane Center Miami FL AL152022 500 PM EDT Sun Oct 30 2022 This morning we were fortunate to have concurrent NOAA and Air Force Reserve Hurricane Hunter missions, which provided a wealth of flight-level, Tail Doppler Radar, and dropsonde data over the system in the central Caribbean Sea. The data indicated that a well-defined, while somewhat broad, circulation had formed with a minimum pressure of 1005 mb. A combination of SFMR winds and surface dropsonde data also suggested that the system had 35-kt winds in its northern semicircle. With that said, the satellite presentation of the system currently lacks sufficient convective organization to be considered a tropical cyclone. However, given the well-defined center and tropical-storm-force winds, there is significant risk for tropical storm conditions in the near future in portions of Jamaica and Grand Cayman Island. With the expectation that this system will likely become a tropical storm soon, advisories have been initiated on Potential Tropical Cyclone Fifteen. The estimated motion of the disturbance is off to the west-northwest at 290/9 kt. This general motion is forecast to continue for the next day or so, as an expansive mid-level ridge is currently centered north of the system and expected to move westward with the cyclone. Toward the end of the forecast period, the ridge may nose further westward as a deep-layer trough becomes established well to the the northeast, which could result in a south of due west motion when the system approaches the coast of Belize. Landfall is expected between the 72- and 96-hour forecast points. The initial NHC track forecast is roughly a blend of the latest GFS and ECMWF guidance, which is also quite close to the HCCA and TCVA consensus aids. Based on the current structure, it may take a bit longer for the convection to become sufficently organized to allow the formation of a tropical cyclone, but this is forecast to occur at some point tonight, likely during the typical diurnal maximum. After deep convection become better established, environmental conditions appear to be conducive for further intensification, especially in the 24-48 hour period when the vertical wind shear is expected to be lowest (5-15 kt) as the system traverses 29-30 C sea-surface temperatures. Mid-level relative humidity is quite low (55-60 percent), but given the relatively low shear, this may act to keep the system`s structure small with a constricted radius of maximum winds. The initial intensity forecast after 24 hours closely follows the latest HCCA and ICON intensity guidance, making the system a Category 1 hurricane in 60-72 hours. The system should weaken quickly over land and is forecast to dissipate before day 5. Based on the latest forecast, the government of Jamaica has issued a Tropical Storm Watch for Jamaica, and the government in the Cayman Islands has issued a Tropical Storm Watch for Grand Cayman Island. Key Messages: 1. Tropical storm conditions are possible within the Tropical Storm Watch areas beginning Monday for Jamaica and on Tuesday for Grand Cayman Island. 2. Interests along the coast of Central America, especially near Belize, should monitor the progress of this system. Additional watches and warnings will likely be required early this week. FORECAST POSITIONS AND MAX WINDS INIT 30/2100Z 15.7N 73.6W 35 KT 40 MPH...POTENTIAL TROP CYCLONE 12H 31/0600Z 16.0N 74.9W 35 KT 40 MPH...TROPICAL CYCLONE 24H 31/1800Z 16.3N 76.6W 40 KT 45 MPH 36H 01/0600Z 16.7N 78.8W 50 KT 60 MPH 48H 01/1800Z 17.2N 81.3W 60 KT 70 MPH 60H 02/0600Z 17.5N 83.6W 65 KT 75 MPH 72H 02/1800Z 17.4N 85.7W 70 KT 80 MPH 96H 03/1800Z 16.4N 89.5W 35 KT 40 MPH...INLAND 120H 04/1800Z...DISSIPATED $$ Forecaster Papin/Cangialosi |
