Issued at 200 PM MST Wed Sep 24 2025
000 WTPZ44 KNHC 242032 TCDEP4 Hurricane Narda Discussion Number 13 NWS National Hurricane Center Miami FL EP142025 200 PM MST Wed Sep 24 2025 Narda has been feeling the impact of 20-25 kt northeasterly wind shear today. As a result, the convective structure has degraded somewhat over the past 6-12 hours. Although recent GPMI and ASCAT fixes indicate that the center is still well underneath the central dense overcast, the area of convection with cloud tops colder than -70C has shrunk significantly and the convection has become slightly more asymmetric. The latest subjective Dvorak estimates are a consensus T-5.0/90 kt from TAFB and SAB. However, the objective intensity estimates from UW-CIMSS have decreased significantly over the past 6-12 hours, and have been mostly in the 65-80 kt range. Taking into account both the subjective and objective intensity estimates, the initial intensity is nudged downward slightly to 85 kt for this advisory. Recent fixes indicate that Narda is moving slightly slower toward the west than earlier, with the current motion estimated at 265/9 kt. A general westward motion will continue over the next 24-36 h, followed by a gradual turn to the west-northwest as the cyclone is steered by a mid-level ridge to its north. A mid-level low over central California is expected to sink southward toward northern Baja California by Friday night, which will erode the ridge and induce a sharp northward turn by Saturday, along with a decrease in forward speed. The official forecast is slightly slower than the previous NHC advisory during the first 2 days, mainly due to the initial position being slightly farther east. After that time, the latest forecast is very near the previous official forecast. The official forecast is closest to the latest TVCE consensus through 60 h, and then lies in between the TVCE and HCCA from days 3-5. The aforementioned strong northeasterly vertical wind shear is expected to continue through the next 12-24 h, then decrease to moderate magnitudes by Thursday afternoon while Narda remains over warm sea-surface temperatures and within a moist environment. The NHC forecast will therefore call for continued weakening through the next 24 h, followed by some restrengthening on Friday. On Saturday, Narda is forecast to move into cooler waters and cross the 26C sea-surface temperature isotherm while reaching a somewhat drier environment. The NHC forecast shows rapid weakening over the weekend as Narda moves over progressively cooler waters. Overall, the latest NHC intensity forecast is slightly lower than the previous prediction. It should be noted that there is a healthy amount of track model spread beyond Day 3. These track differences will determine what water temperatures Narda encounters in 3-5 days, which will affect the intensity forecast (how quickly Narda weakens during that time period). FORECAST POSITIONS AND MAX WINDS INIT 24/2100Z 15.1N 112.3W 85 KT 100 MPH 12H 25/0600Z 15.3N 114.2W 80 KT 90 MPH 24H 25/1800Z 15.6N 116.7W 75 KT 85 MPH 36H 26/0600Z 16.0N 119.3W 75 KT 85 MPH 48H 26/1800Z 16.6N 121.5W 85 KT 100 MPH 60H 27/0600Z 17.3N 123.4W 90 KT 105 MPH 72H 27/1800Z 18.2N 124.4W 85 KT 100 MPH 96H 28/1800Z 20.1N 124.5W 55 KT 65 MPH 120H 29/1800Z 21.9N 123.5W 40 KT 45 MPH...POST-TROPICAL $$ Forecaster Hagen
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