Issued at 800 PM MST Tue Sep 23 2025
463 WTPZ44 KNHC 240252 TCDEP4 Hurricane Narda Discussion Number 10 NWS National Hurricane Center Miami FL EP142025 800 PM MST Tue Sep 23 2025 Narda appears to have strengthened since the previous advisory, with an eye, albeit cloud-filled and cold, periodically evident in visible and infrared satellite imagery. The cyclone continues to experience easterly vertical wind shear, with outflow restricted in the eastern semicircle. This is evident in satellite imagery and confirmed by the latest UW-CIMSS shear analysis, which indicates 19 kt of easterly shear. Subjective Dvorak estimates from TAFB and SAB were 4.5/77 kt and 5.0/90 kt, respectively, while objective estimates from UW-CIMSS ranged from 80 to 93 kt. Taking a blend of these data, and accounting for the improved satellite presentation, supports raising the initial intensity to 85 kt for this advisory. Narda is estimated to be moving just south of due west, or 265 degrees, at 11 kt. A general westward motion is expected to continue during the next couple of days as the cyclone is steered by a strengthening subtropical ridge to its north and northwest. A turn toward the northwest is expected around day 3 as a mid-level low over southern California erodes the eastern portion of the subtropical ridge. A more northward motion with a decrease in forward speed is forecast by days 4 and 5 as the cyclone moves into the weakness in the subtropical ridge created by the mid-level low to its north. The official forecast track is very similar to the previous advisory and remains close to the middle of the track guidance envelope. Narda will remain embedded within a moist air mass and over very warm waters during the next couple of days. Shear will hold at moderate levels tonight, which may allow for some slight strengthening, and this is reflected in the intensity forecast. The easterly shear is then forecast to increase to near 30 kt on Wednesday, and this is expected to disrupt the cyclone enough to cause some weakening. Narda should move out of the moderate to strong easterly shear while remaining over warm waters and surrounded by moist mid-level air on Thursday. This environment should allow for a period of re-intensification, with Narda forecast to peak at major hurricane strength around day 3. Sea surface temperatures will gradually decrease late in the forecast period, with Narda crossing the 26C isotherm around day 4. The cyclone will also be moving into a much drier mid-level airmass and a more stable environment, which should result in steady weakening by day 4 and rapid weakening by day 5. The official intensity forecast is most closely aligned with the HCCA intensity aid. FORECAST POSITIONS AND MAX WINDS INIT 24/0300Z 15.3N 109.4W 85 KT 100 MPH 12H 24/1200Z 15.2N 111.0W 90 KT 105 MPH 24H 25/0000Z 15.2N 113.3W 80 KT 90 MPH 36H 25/1200Z 15.4N 115.6W 80 KT 90 MPH 48H 26/0000Z 15.8N 118.1W 85 KT 100 MPH 60H 26/1200Z 16.3N 120.3W 90 KT 105 MPH 72H 27/0000Z 17.1N 121.9W 100 KT 115 MPH 96H 28/0000Z 19.0N 123.4W 85 KT 100 MPH 120H 29/0000Z 21.5N 123.0W 55 KT 65 MPH $$ Forecaster Jelsema (CPHC)
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