Tropical Storm Nolo

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WTPA42 PHFO 240252
TCDCP2
 
Tropical Storm Nolo Discussion Number  14
NWS Central Pacific Hurricane Center Honolulu HI   EP152026
Issued by NWS National Hurricane Center Miami FL
500 PM HST Wed Sep 23 2026
 
Nolo's convective organization has improved slightly during the past 
several hours, with persistent deep convection within a curved band 
wrapping into the circulation from the north around the western 
semicircle. The latest subjective Dvorak intensity estimates from 
JTWC and HFO are both T2.0/30 kt, while objective intensity 
estimates range from 30 to 40 kt. Given the improved convective 
organization and the higher objective estimates, the initial 
intensity was increased to 40 kt in the 2 PM HST intermediate 
advisory and is maintained for this advisory.
 
Nolo is moving west-northwestward, with an initial motion of 285/5 
kt. A weakening subtropical ridge to the north should allow 
Nolo to slow down and turn northward tonight into Thursday, followed 
by a north-northeastward motion as an upper-level trough deepens 
northwest of the Hawaiian Islands. As the trough moves westward and 
the subtropical ridge rebuilds north of Hawaii, Nolo is forecast to 
make a sharp westward turn Friday night into Saturday. The latest 
GDMI and HCCA guidance has shifted slightly to the left, taking Nolo 
farther south of the Big Island. The NHC track forecast reflects a 
blend of the previous forecast and these aids, and shows Nolo 
passing about 85 n mi south of the Big Island on Saturday, then 
about 215 n mi south of the smaller Hawaiian Islands during the 
latter portion of the weekend. However, uncertainty remains 
regarding exactly when and where the sharp westward turn will occur, 
with the ECMWF remaining on the right side of the guidance envelope 
and bringing Nolo closer to the islands.
 
Environmental conditions remain favorable for strengthening, with 
very warm sea surface temperatures and plenty of mid-level moisture 
along the forecast track. However, around 10 kt of easterly vertical 
wind shear may temper the rate of intensification during the next 24 
to 36 h. As the shear relaxes and Nolo continues to develop an inner 
core, a faster rate of intensification is forecast while the cyclone 
moves northward to north-northeastward during the next couple of 
days. These conditions could support rapid intensification, and Nolo 
is forecast to become a hurricane by Thursday night and reach major 
hurricane strength on Saturday as it passes south of the Big Island. 
The latest NHC intensity forecast hovers near the upper end of the 
guidance envelope throughout the forecast period.
 
Key Messages:
 
1. Tropical Storm Nolo is expected to strengthen into a hurricane
by Thursday night as it turns northward, potentially making its
closest approach to the Big Island of Hawaii on Saturday. A
Hurricane Watch remains in effect for the Big Island, and residents
there should follow advice given by local officials, including
evacuating if told to do so.

2. The time to prepare for significant heavy rain and flooding
impacts on the Big Island is now, as heavy rain becomes more likely
by Thursday and Friday. Periods of heavy rain are likely 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 Big Island and
Maui. Across the remainder of Hawaii, lesser rainfall totals are
expected, with isolated flooding possible.

3. Large and damaging waves are possible along the coast of the
Big Island into the weekend.

4. Interests elsewhere in Hawaii should closely monitor the latest
forecast updates and ensure that they have their preparedness plans
in place.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  24/0300Z 14.7N 155.9W   40 KT  45 MPH
 12H  24/1200Z 14.8N 156.0W   50 KT  60 MPH
 24H  25/0000Z 15.4N 155.8W   60 KT  70 MPH
 36H  25/1200Z 16.2N 155.3W   70 KT  80 MPH
 48H  26/0000Z 17.1N 155.0W   80 KT  90 MPH
 60H  26/1200Z 17.5N 155.1W   90 KT 105 MPH
 72H  27/0000Z 17.4N 156.2W  100 KT 115 MPH
 96H  28/0000Z 17.5N 158.6W  105 KT 120 MPH
120H  29/0000Z 18.9N 162.1W  100 KT 115 MPH
 
$$
Forecaster Gibbs