Issued at 200 AM MST Wed Sep 24 2025
793 WTPZ44 KNHC 240841 TCDEP4 Hurricane Narda Discussion Number 11 NWS National Hurricane Center Miami FL EP142025 200 AM MST Wed Sep 24 2025 The low-level center of Narda has been mostly obscured by a central dense overcast with cloud-top temperatures of -70 to -85C, following a brief eye feature that developed near the time of the previous advisory package. Since then, the cyclone has begun to feel the effects of increasing vertical wind shear. UW-CIMSS now analyzes 22 kt of east-northeasterly shear, and satellite imagery shows increasing outflow restriction in the eastern semicircle. Subjective Dvorak estimates from TAFB and SAB were both 5.0/90 kt, while objective estimates from UW-CIMSS ranged from 84 to 101 kt. Taking a blend of these data, the initial intensity for this advisory has been raised to 90 kt. 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 by 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 ridge created by the mid-level low. The official forecast track is very similar to the previous advisory for the next couple of days, then was shifted slightly to the left beyond 48 hours to better align with trends in the consensus guidance. Narda will remain embedded within a moist air mass and over very warm waters during the next couple of days. Despite these favorable conditions for intensification, east-northeasterly shear is forecast to increase to near 30 kt later today and tonight, which is expected to disrupt the cyclone enough to cause some weakening. Narda should emerge from the hostile shear environment on Thursday while still over warm waters and surrounded by moist mid-level air. This should allow for a period of re-intensification, with Narda forecast to peak at major hurricane strength around day 3. Sea surface temperatures will decrease rather abruptly beyond day 3, with Narda crossing the 26C isotherm prior to day 4 while also moving into a progressively drier and more stable environment. As a result, rapid weakening is forecast by days 4 and 5, with Narda expected to lose deep convection and become a post-tropical low by day 5. The official intensity forecast is similar to the previous prediction and most closely aligned with a blend of the HCCA and FSSE intensity aids. FORECAST POSITIONS AND MAX WINDS INIT 24/0900Z 15.1N 110.5W 90 KT 105 MPH 12H 24/1800Z 15.1N 112.2W 85 KT 100 MPH 24H 25/0600Z 15.2N 114.5W 80 KT 90 MPH 36H 25/1800Z 15.5N 116.9W 80 KT 90 MPH 48H 26/0600Z 15.9N 119.5W 85 KT 100 MPH 60H 26/1800Z 16.6N 121.7W 95 KT 110 MPH 72H 27/0600Z 17.6N 123.3W 100 KT 115 MPH 96H 28/0600Z 19.4N 124.3W 75 KT 85 MPH 120H 29/0600Z 21.8N 123.8W 45 KT 50 MPH...POST-TROPICAL $$ Forecaster Jelsema (CPHC)
Source link