Post-Tropical Cyclone Irwin Forecast Discussion (Text)

Home   Public Adv   Discussion   Wind Probs   Graphics   Archive  

WTPZ45 KNHC 292035

Post-Tropical Cyclone Irwin Discussion Number  12
NWS National Hurricane Center Miami FL       EP102023
1100 AM HST Tue Aug 29 2023

Irwin has failed to produce any convection near its center during 
the last 15-18 h. Since it no longer satisfies the criteria of a 
tropical cyclone, Irwin is being designated as a post-tropical 
cyclone with this advisory. A recent scatterometer pass showed a 
broad area of winds at or slightly above 30 kt in the northwestern 
quadrant, and so the initial intensity remains 35 kt.

The post-tropical cyclone is moving slightly south of due west 
(260/15 kt). A general westward motion at a gradually slower forward 
speed is expected over the next several days while Irwin is steered 
by a low-level ridge over the eastern Pacific. Gradual weakening is 
forecast as the shallow cyclone spins down over cooler waters and in 
a drier, more stable environment. While some intermittent bursts of 
convection could occur during the next couple of days, the overall 
environment does not appear conducive for Irwin to regenerate to a 
tropical cyclone.

This is the last NHC advisory on Irwin. For additional information 
on the post-tropical cyclone, please see High Seas Forecasts issued 
by the National Weather Service, under AWIPS header NFDHSFEPI, WMO 
header FZPN02 KWBC, and on the web at 


INIT  29/2100Z 19.1N 130.3W   35 KT  40 MPH...POST-TROPICAL
 12H  30/0600Z 18.9N 132.4W   30 KT  35 MPH...POST-TROP/REMNT LOW
 24H  30/1800Z 18.8N 134.7W   30 KT  35 MPH...POST-TROP/REMNT LOW
 36H  31/0600Z 18.8N 136.5W   30 KT  35 MPH...POST-TROP/REMNT LOW
 48H  31/1800Z 18.9N 138.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
 60H  01/0600Z 19.0N 139.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  01/1800Z 19.0N 140.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  02/1800Z 19.0N 141.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  03/1800Z 19.5N 143.5W   20 KT  25 MPH...POST-TROP/REMNT LOW

Forecaster Reinhart

Standard version of this page

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

Contact Us

NOAA/ National Weather Service
National Centers for Environmental Prediction
National Hurricane Center
11691 SW 17th Street
Miami, Florida, 33165-2149 USA
Privacy Policy
About Us
Career Opportunities
Page last modified: Tuesday, 29-Aug-2023 20:36:05 UTC