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| #903748 (Received by flhurricane at: 11:07 AM 19.Sep.2017) TCDAT5 Hurricane Maria Discussion Number 14 NWS National Hurricane Center Miami FL AL152017 1100 AM AST Tue Sep 19 2017 Reports from an Air Force Reserve Hurricane Hunter Aircraft indicate that Maria regained category 5 status shortly after the last advisory, and that it is currently maintaining an intensity near 140 kt with a central pressure near 927 mb. The aircraft data suggests an outer wind maximum that could be the start of an eyewall replacement cycle, but this feature does not yet have a good signature in radar data or microwave imagery. The eye of Maria has been wobbling quite a bit, but a smoother long-term motion is 300/9. There is little change to the track forecast reasoning or the forecast track since the previous advisory. A weak ridge situated over the western Atlantic is expected to steer Maria west-northwestward through 48 hours, and on this track the center of the hurricane is forecast to pass near or over the Virgin Islands and Puerto Rico on Wednesday. After that time, the western portion of the ridge is forecast to weaken, partially due to the influence of the large circulation of Hurricane Jose off the U.S. east coast. This pattern should cause Maria to turn northwestward and then north-northwestward by days 4-5. The track guidance is tightly clustered through 72 h and fairly well clustered at 120 h, and the new track is to the left of center of the cluster mainly between the GFS and ECMWF models. Maria should remain in a generally favorable environment through 48 h, and based on this and the latest guidance the new intensity forecast keeps Maria at 135-140 kt up to the time of landfall in Puerto Rico. After crossing Puerto Rico, the upper-level winds are expected to become less favorable, and the intensity forecast shows a slow weakening that follows the upper edge of the guidance. A complication to the intensity forecast is that there will likely be fluctuations caused by eyewall replacement cycles superimposed on top of the general trends shown in the official forecast. KEY MESSAGES: 1. Maria will continue to affect portions of the Leeward Islands today and the core of the hurricane is expected to move near or over Puerto Rico and the Virgin Islands tonight and Wednesday. Everyone in these areas should follow advice from local officials to avoid life-threatening flooding from storm surge and rainfall. 2. Wind speeds atop and on the windward sides of hills and mountains and on high-rise buildings could be much stronger than the near- surface winds indicated in this advisory. FORECAST POSITIONS AND MAX WINDS INIT 19/1500Z 16.3N 63.1W 140 KT 160 MPH 12H 20/0000Z 17.0N 64.1W 140 KT 160 MPH 24H 20/1200Z 18.0N 65.7W 135 KT 155 MPH 36H 21/0000Z 18.8N 67.1W 125 KT 145 MPH 48H 21/1200Z 19.6N 68.4W 125 KT 145 MPH 72H 22/1200Z 21.5N 70.5W 120 KT 140 MPH 96H 23/1200Z 24.5N 72.0W 105 KT 120 MPH 120H 24/1200Z 27.5N 72.5W 95 KT 110 MPH $$ Forecaster Beven |
