ZCZC MIATCDEP2 ALL TTAA00 KNHC DDHHMM Tropical Depression Greg Discussion Number 35 NWS National Hurricane Center Miami FL EP072017 800 PM PDT Tue Jul 25 2017 A new burst of convection has developed over the western side of the circulation of Greg during the past couple of hours, helping to maintain the system as a 30-kt depression. The current convection is expected to be relatively short lived, however, as southerly shear should increase over the cyclone due to a sharp upper-level shear axis located to its southwest. At the same time, the cyclone will continue to move into a drier and more stable airmass, and over increasingly cooler waters. Over the next 24 hours, the shear is expected to increase even further and turn out of the northwest. This will induce further weakening, and organized deep convection is expected to be sheared away from the system's circulation by Wednesday night. Therefore, the NHC forecast calls for Greg to degenerate into a remnant low by that time, but it could occur sooner. The remnant low is then likely to open up into a trough by day 4 or 5. Greg has been moving northwestward at 310/12 kt. The forecast track reasoning remains the same as the previous forecast, as low- to mid-level troughing north of the depression should maintain a northwestward or west-northwestward motion for the next 24 hours or so. After that time, the remnant low should turn westward and then west-southwestward, embedded in the low-level trade winds forced by surface high pressure to the north. Model guidance is tightly clustered through 36 hours, but then begins to spread a little, likely due to differences in the strength of the low-level ridge. The latest NHC track is near the GFS/ECMWF consensus. FORECAST POSITIONS AND MAX WINDS INIT 26/0300Z 17.2N 138.8W 30 KT 35 MPH 12H 26/1200Z 17.8N 139.7W 30 KT 35 MPH 24H 27/0000Z 18.2N 141.2W 25 KT 30 MPH...POST-TROP/REMNT LOW 36H 27/1200Z 18.3N 143.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 28/0000Z 18.0N 144.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 29/0000Z 17.0N 147.6W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 30/0000Z 16.0N 150.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 31/0000Z...DISSIPATED $$ Forecaster Latto/Cangialosi 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 12:10:14 UTC