Advisories

000
WTPA42 PHFO 260248
TCDCP2
 
Hurricane Nolo Discussion Number  22
NWS Central Pacific Hurricane Center Honolulu HI   EP152026
Issued by NWS National Hurricane Center Miami FL
500 PM HST Fri Sep 25 2026
 
The satellite appearance of Nolo has changed little since the last 
advisory. However, WSR-88D radar data from South Point, Hawaii, 
indicates that the eye has contracted to a diameter of about 35 n 
mi. While this suggests some strengthening has occurred, the 
Doppler velocities have changed little since the last advisory. 
Based on a blend of earlier aircraft data, satellite intensity 
estimates, and radar velocities, the initial intensity is held at 
90 kt. Shear analyses show that Nolo is being affected by 10-15 kt 
of southeasterly shear, and this may be helping to advect dry air 
into the circulation as seen in the radar data.

The initial motion is now 010/3. The guidance is in excellent 
agreement that Nolo should stall and then turn westward in the next 
12 h or so as mid- to upper-level ridge builds westward north of 
the Hawaiian Islands.  The track guidance has shifted southward 
since the last advisory, and the first 60 h of the forecast track 
are near the northern edge of the guidance envelope.  After 60 h, 
the hurricane is forecast to turn northward between the ridge and 
the mid- to upper-level trough currently northwest of Hawaii. By 
120 h, there is some divergence in the track guidance due to how 
the tropical cyclone and the trough interact. For now, this portion 
of the forecast track is similar to the previous track.

Due to the shear and the apparent dry air entrainment, the new 
intensity forecast has a slower development rate during the first 
12-24 h. From 24-72 h, the HAFS models continue to forecast Nolo to 
become a major hurricane. However, the SHIPS models forecast no 
strengthening whatsoever, and instead they forecast the cyclone to 
slowly weaken through the forecast period.  This portion of the 
intensity forecast will lean towards the HAFS models, but it has 
increasing uncertainty. After 72 h, weakening is expected due
to the forecast strong southwesterly shear east of the 
aforementioned trough.
 
 
Key Messages:
 
1. Nolo is expected to remain south of the Big Island of Hawaii
through Saturday before turning westward and moving away from the
island. Tropical storm conditions are expected to begin on the Big
Island tonight with hurricane conditions possible on Saturday,
particularly in areas of steep terrain. Residents should follow
advice given by local officials, including evacuating if told to do
so. 
 
2. The time to finish preparations for significant heavy rain and
flooding impacts on the Big Island is now as heavy rain increases in
both coverage and intensity late today. Periods of heavy rain are
expected to continue across the Big Island and Maui through the
weekend. Life-threatening, catastrophic flooding and mudslides are
possible, especially in areas of steep terrain across the eastern
and southern portions of the Big Island and Maui. Across the
remainder of Hawaii, lesser rainfall totals are expected, with
isolated flooding possible.
 
3. Large and damaging waves are likely along portions of the
Big Island's coastline into the weekend.
 
4. A Tropical Storm Watch is in effect for Maui County where
tropical storm conditions are possible beginning on Saturday.
Interests elsewhere in Hawaii should closely monitor the latest
forecast updates and ensure that they have their preparedness plans
in place. Regardless of the exact track of Nolo, strong and gusty 
winds are expected for all of the Hawaiian Islands through the 
weekend.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  26/0300Z 16.9N 155.3W   90 KT 105 MPH
 12H  26/1200Z 17.1N 155.5W   90 KT 105 MPH
 24H  27/0000Z 17.1N 156.4W   95 KT 110 MPH
 36H  27/1200Z 16.9N 157.9W  100 KT 115 MPH
 48H  28/0000Z 16.9N 159.8W  110 KT 125 MPH
 60H  28/1200Z 17.7N 161.7W  120 KT 140 MPH
 72H  29/0000Z 19.1N 163.2W  115 KT 130 MPH
 96H  30/0000Z 22.0N 164.5W   90 KT 105 MPH
120H  01/0000Z 23.6N 165.5W   65 KT  75 MPH
 
$$
Forecaster Beven