Show Selection: |
#898936 (Received by flhurricane at: 10:35 PM 19.Aug.2017) TCDAT4 Remnants Of Harvey Discussion Number 11 NWS National Hurricane Center Miami FL AL092017 1100 PM EDT Sat Aug 19 2017 An Air Force Reserve Hurricane Hunter aircraft investigated Harvey earlier this evening and was unable to close off a center of circulation. The plane found a well-defined wind shift across the wave axis, and winds decreased as the plane flew south along the axis toward a pressure minimum south of 14N. Harvey has therefore degenerated into an open wave, and this will be the last advisory. Maximum surface winds, as measured by the plane, remain 30 kt. As a side note, the associated deep convection has continued to lose organization and is now oriented linearly from northeast to southwest along the wave axis. Harvey's remnants are moving quickly westward with a motion of 275/19 kt. A fast westward to west-northwestward motion is expected to continue for the next couple of days as the wave moves along the southern periphery of the subtropical ridge. A break in the ridge caused by a mid- to upper-level low over the Gulf of Mexico could cause the system to turn northwestward and slow down as it moves across the Yucatan Peninsula and into the Bay of Campeche in 3-5 days. The global models, particularly the GFS and ECMWF, deserve a lot of credit for showing Harvey dissipating, or at least not strengthening, over the Caribbean Sea. Even though the vertical shear that has been plaguing the system is expected to diminish in 24-48 hours, the system's fast motion and ambient dry air will likely keep Harvey's remnants from regenerating into a tropical cyclone in the near term. For that reason, the solutions shown by the GFS, ECMWF, and UKMET appear most reasonable, keeping the system as an open wave, or possibly regenerating to a tropical depression before it reaches Belize and the Yucatan coast. Regeneration is also possible if the remnants emerge over the Bay of Campeche. The remnants of Harvey will be monitored for signs of regeneration and for the possibility of bringing tropical storm conditions to Belize and the Yucatan Peninsula of Mexico during the next couple of days. If necessary, advisories could be resumed and tropical storm watches or warnings issued before Harvey regains tropical cyclone status. Please refer to the Atlantic Tropical Weather Outlook for this system's potential to regenerate into a tropical cyclone, beginning with the 2 AM issuance on Sunday morning. FORECAST POSITIONS AND MAX WINDS INIT 20/0300Z 14.3N 71.8W 30 KT 35 MPH...REMNANTS OF HARVEY 12H 20/1200Z...DISSIPATED $$ Forecaster Berg |