ZCZC MIATCDEP2 ALL TTAA00 KNHC DDHHMM Hurricane Aletta Discussion Number 14 NWS National Hurricane Center Miami FL EP022018 900 PM MDT Fri Jun 08 2018 Aletta's weakening phase has begun, with the eye becoming cloud filled in visible satellite imagery since the last advisory. An analysis from CIMSS at the University of Wisconsin indicates that vertical shear has increased to 15-20 kt out of the south-southwest, and a 2309 UTC SSMI/S pass confirms that the hurricane's structure is responding to that shear. All final-T numbers have decreased, and the initial intensity is set at 110 kt as a blend of the various final-T and CI numbers. This is also supported by the latest SATCON estimate. Vertical shear is forecast to strengthen during the next 36 hours, and Aletta will be moving over marginally warm sea surface temperatures, both of which should cause the cyclone to continue weakening. The new intensity models are now showing a much more significant rate of weakening, and the updated NHC intensity forecast follows suit, bringing down the winds much faster than shown in the previous forecast. The NHC forecast is near the top end of the guidance for the first 24 hours and then close to the ICON intensity consensus from 36 hours and beyond. Interestingly, the HCCA guidance weakens Aletta to a tropical storm within 24 hours, so it wouldn't be surprising if the hurricane weakens faster than shown in the official forecast. Aletta is now forecast to degenerate into a remnant low by day 3. The initial motion estimate is 285/5 kt. Since Aletta is moving around the southwestern periphery of a mid-level ridge centered over northwestern Mexico, the cyclone is expected to maintain a slow west-northwestward or northwestward motion for the next 36 hours. After that time, the weakening storm should turn back toward the west and eventually southwest as it becomes increasingly steered by the low-level trade winds and the flow around another developing tropical cyclone to the east. The new NHC track forecast is a little south of the previous forecast to account for an overall southward shift in the guidance envelope. FORECAST POSITIONS AND MAX WINDS INIT 09/0300Z 16.2N 112.3W 110 KT 125 MPH 12H 09/1200Z 16.6N 113.1W 95 KT 110 MPH 24H 10/0000Z 17.3N 114.2W 75 KT 85 MPH 36H 10/1200Z 17.7N 115.2W 55 KT 65 MPH 48H 11/0000Z 17.8N 116.3W 40 KT 45 MPH 72H 12/0000Z 17.8N 118.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 13/0000Z 17.5N 121.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 14/0000Z 16.5N 122.5W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Berg NNNN
Alternate Formats
About Alternates -
E-Mail Advisories -
RSS Feeds
Cyclone Forecasts
Latest Advisory -
Past Advisories -
About Advisories
Marine Forecasts
Latest Products -
About Marine Products
Tools & Data
Satellite Imagery -
US Weather Radar -
Aircraft Recon -
Local Data Archive -
Forecast Verification -
Deadliest/Costliest/Most Intense
Learn About Hurricanes
Storm Names
Wind Scale -
Prepare -
Climatology -
NHC Glossary -
NHC Acronyms -
Frequently Asked Questions -
AOML Hurricane-Research Division
About Us
About NHC -
Mission/Vision -
Other NCEP Centers -
NHC Staff -
Visitor Information -
NHC Library
NOAA/
National Weather Service
National Centers for Environmental Prediction
National Hurricane Center
11691 SW 17th Street
Miami, Florida, 33165-2149 USA
nhcwebmaster@noaa.gov
Disclaimer
Privacy Policy
Credits
About Us
Glossary
Career Opportunities
Page last modified: Monday, 31-Dec-2018 12:10:12 UTC