Advisories

000
WTPA44 PHFO 110234
TCDCP4
 
Post-Tropical Cyclone Lowell Discussion Number  60
NWS Central Pacific Hurricane Center Honolulu HI   EP122026
Issued by NWS National Hurricane Center Miami FL
500 PM HST Thu Sep 10 2026
 
It has now been roughly 24 hours since Lowell produced more than 
just patches of deep convection on its northeast side. This activity 
has lacked much organization over this time span, with continued 
westerly vertical wind shear keeping the low-level circulation 
exposed. Given that Lowell has lacked organized convection near its 
center for about a day, and with most of the global and 
hurricane-regional model guidance not showing a return of deep 
convection for at least another 24 h, Lowell is being declared a 
post-tropical cyclone this advisory. The maximum sustained winds 
remain 45 kt, however, based on scatterometer data received after 
the prior advisory. 

The post-tropical low is still moving westward at 270/12 kt. Much of 
the forecast reasoning has not changed despite the cyclone's status 
change, with a deep-layer cutoff low expected to pick up the 
post-tropical low, pinwheeling it around to the northwest, west, 
then southward in the 24-72 h period. There continue to be 
differences in the model guidance on how sharp of a cyclonic turn 
around the upper-level low there will be, but ultimately the 
guidance shows the post-tropical low being deposited back south 
after the upper-level feature bypasses it to the east in 72-96 h.  
 
As mentioned above, most of the model guidance does not show deep 
convection returning near the post-tropical cyclone for the next day 
or so. However, an upper-level cutoff low is still forecast to drop 
southward and induce some sheared convection this weekend. However, 
given the disorganized state of the post-tropical cyclone, this 
brief period of favorable convective forcing does not appear to last 
long enough for the system to redevelop into a tropical cyclone, 
especially given that the GFS and ECMWF-based SHIPS guidance shows 
vertical wind shear remaining in the 30-40 kt range. After the 
upper-level cutoff passes it by to the east, the low is expected to 
slowly fill, with much of the model guidance showing the low opening 
up into a trough by 120 h, which is now reflected in the NHC 
forecast.

This is the final advisory on Lowell unless regeneration occurs. For 
additional information on the post-tropical low please see High Seas 
Forecasts issued by the National Weather Service, under AWIPS header 
NFDHSFEPI, WMO header FZPN01 KWBC, and on the web at 
ocean.weather.gov/shtml/NFDHSFEPI.php

 
KEY MESSAGES:
 
1. Post-storm safety: Follow advice of local officials and avoid
areas of downed power lines and flooding. Ensure generators are
properly ventilated and placed outside at least 20 feet away from
dwellings and garages to avoid carbon monoxide poisoning. During
clean up, be careful when using chainsaws and power tools. Drink
plenty of water to avoid heat exhaustion.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  11/0300Z 29.0N 169.9W   45 KT  50 MPH...POST-TROPICAL
 12H  11/1200Z 29.2N 171.3W   40 KT  45 MPH...POST-TROPICAL
 24H  12/0000Z 30.6N 172.0W   40 KT  45 MPH...POST-TROPICAL
 36H  12/1200Z 32.7N 172.8W   45 KT  50 MPH...POST-TROPICAL
 48H  13/0000Z 34.0N 175.0W   40 KT  45 MPH...POST-TROPICAL
 60H  13/1200Z 33.6N 176.7W   35 KT  40 MPH...POST-TROPICAL
 72H  14/0000Z 32.9N 177.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
 96H  15/0000Z 31.5N 176.6W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  16/0000Z...DISSIPATED
 
$$
Forecaster Papin