Tropical Cyclone Discussion
259 WTPA42 PHFO 032040 TCDCP2 Hurricane Nolo Discussion Number 53 NWS Central Pacific Hurricane Center Honolulu HI EP152026 Issued by NWS National Hurricane Center Miami FL 1100 AM HST Sat Oct 03 2026 Nolo continues to display a compact and nearly symmetric pattern in satellite imagery, and infrared imagery shows that cloud tops around the eye have cooled since the last full advisory. Based on the improved structure, Nolo was upgraded to a 100-kt major hurricane on the 8 AM HST intermediate advisory. Since then, HFO and JTWC each provided Dvorak estimates of T5.5/102 kt, and the highest UW-CIMSS objective numbers are around that same value. The intensity of 100 kt is therefore maintained on this advisory. The forward speed has continued to increase this morning and is now about 15 kt, with Nolo being steered quickly westward by an expanding mid-level ridge to its north. The hurricane's speed is likely to oscillate between 15 and 20 kt for much of the upcoming 5 days as ridging remains established at varying magnitudes. The track guidance remains more tightly clustered than usual for the first 3 days of the forecast, and Nolo is expected to cross the International Date Line in 24-30 hours. The model spread is a little higher on days 4 and 5. Some models, including the European, HAFS-B, GDMI, and HCCA show a continued westward trajectory, while the GFS, HAFS-A, HWRF, and COAMPS-TC show a bit of a turn toward the northwest or north. These scenarios appear to be related to how much Nolo might interact with a disturbance currently near the Marshall Islands (Invest 94W) and a longwave trough expected to move east of Japan. For now, the NHC forecast continues to favor the more westward scenario. Low shear and warm sea surface temperatures around 28 degrees Celsius should support further intensification during the next day or so, but intensity guidance suggests the period of rapid intensification is complete. In fact, recent microwave data show a moat now surrounding the eyewall, with a secondary eyewall potentially forming about 25-30 n mi out from the center. This could mean an eyewall replacement is about to occur, which typically leads to fluctuations in intensity in the short term. If the eyewall replacement occurs quickly enough, Nolo could reach a higher peak intensity in 24-36 hours before shear begins to increase. The increased shear and surrounding dry environment are likely to cause significant weakening in the 3- to 5-day forecast period, and the NHC forecast has been lowered during that time frame compared to the previous advisory. FORECAST POSITIONS AND MAX WINDS INIT 03/2100Z 23.2N 173.1W 100 KT 115 MPH 12H 04/0600Z 23.3N 175.8W 110 KT 125 MPH 24H 04/1800Z 23.8N 179.1W 115 KT 130 MPH 36H 05/0600Z 24.7N 177.6E 115 KT 130 MPH 48H 05/1800Z 25.1N 174.5E 110 KT 125 MPH 60H 06/0600Z 25.3N 170.9E 100 KT 115 MPH 72H 06/1800Z 25.6N 166.6E 90 KT 105 MPH 96H 07/1800Z 26.5N 158.5E 70 KT 80 MPH 120H 08/1800Z 27.3N 152.3E 60 KT 70 MPH