ZCZC MIATCDEP4 ALL TTAA00 KNHC DDHHMM Tropical Depression Nine-E Discussion Number 4 NWS National Hurricane Center Miami FL EP092017 400 AM CDT Sat Jul 22 2017 The satellite appearance of the depression hasn't changed much during the past 6 hours, and the intensity remains 30 kt based on an average of Dvorak estimates from TAFB, SAB, and the UW-CIMSS ADT. Most of the convection is still removed from the center and limited to the western half of the circulation. That said, the intensity forecast thinking hasn't changed, and the environment is still expected to support strengthening throughout the forecast period. Given the current structure of the storm, significant intensification doesn't seem imminent. However, looking at the medium-term, the SHIPS-RII probability of an increase of 65 kt in 72 hours is up to 44 percent. The new intensity forecast is a little lower than the previous forecast for the first 48 h, but similar after that. The forecast remains above all of the guidance for the first two days, and near the SHIPS model after that. The initial motion is 285/11 kt. A mid-level ridge extending from the Gulf of Mexico to western Mexico is the primary steering feature for next few days, and the models are in good agreement on a steady northwestward track beginning later today. All of the global models depict the ridge strengthening after about 72 h, but the extent to which the cyclone responds by turning toward the west varies somewhat. In the models with a stronger vortex, most notably the GFS, a weak upper-level low prevents the storm from turning too sharply toward the west. A weaker modeled storm, as depicted in the UKMET and HWRF would turn almost due west. Overall, the guidance has shifted a little to the west for this advisory, so the forecast has been nudged in that direction. It now lies on the right side of the envelope, favoring the stronger solution of the GFS. FORECAST POSITIONS AND MAX WINDS INIT 22/0900Z 9.6N 96.6W 30 KT 35 MPH 12H 22/1800Z 10.1N 98.2W 35 KT 40 MPH 24H 23/0600Z 11.1N 100.1W 45 KT 50 MPH 36H 23/1800Z 12.1N 101.8W 55 KT 65 MPH 48H 24/0600Z 13.2N 103.4W 65 KT 75 MPH 72H 25/0600Z 15.1N 106.5W 85 KT 100 MPH 96H 26/0600Z 16.8N 109.9W 90 KT 105 MPH 120H 27/0600Z 18.0N 113.5W 95 KT 110 MPH $$ Forecaster Zelinsky 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: Sunday, 31-Dec-2017 12:10:18 UTC