ZCZC MIATCDEP2 ALL TTAA00 KNHC DDHHMM Hurricane Linda Discussion Number 11 NWS National Hurricane Center Miami FL EP122021 300 PM MDT Thu Aug 12 2021 There hasn't been much change to Linda's structure since this morning. The hurricane's center is embedded within a small Central Dense Overcast, and a dimple is evident in visible satellite images where an eye would be likely to form. For the most part, satellite intensity estimates have not changed from this morning, and a 1550 UTC ASCAT-A pass showed peak winds in the 55-60 kt range. Given that instrument's typical undersampling, especially for a small cyclone, the 65-kt initial intensity still seems appropriate. Linda is moving toward the west-northwest, or 300/8 kt, to the south of a mid-tropospheric ridge located over northern Mexico. This ridge, and a stronger mid-level high developing over the western United States, are expected to continue driving Linda toward the west-northwest for the next 2-3 days. By days 4 and 5, another mid-level high is forecast to develop between Hawaii and Alaska, and that feature is likely to block Linda's northward progress, and possibly even cause a south-of-due-west motion by the end of the forecast period. The track guidance is in good agreement on this scenario, and the updated NHC track forecast has been nudged southward mainly on days 4 and 5. It should be noted that this new forecast is not as far south as several of the track models, and additional southward adjustments may be required in subsequent forecasts. Various shear analyses suggest that the northerly shear affecting Linda may have decreased slightly, with the magnitude now on the order of 10-15 kt. SHIPS diagnostics indicate that this level of shear is likely to continue for another 24 hours or so, and then it could decrease further and enable some gradual strengthening. Models generally show Linda's intensity peaking and leveling off in the 36-60 hour window. After 60 hours, Linda is expected to move into a less favorable thermodynamic environment, highlighted by colder sea surface temperatures and drier, more stable air, and weakening is therefore shown on days 3-5. One important note is that further southward shifts in the forecast track would keep Linda over warmer waters and potentially slow the cyclone's weakening trend. FORECAST POSITIONS AND MAX WINDS INIT 12/2100Z 15.3N 108.7W 65 KT 75 MPH 12H 13/0600Z 16.0N 110.3W 70 KT 80 MPH 24H 13/1800Z 17.0N 112.4W 75 KT 85 MPH 36H 14/0600Z 17.9N 114.6W 80 KT 90 MPH 48H 14/1800Z 18.7N 116.8W 80 KT 90 MPH 60H 15/0600Z 19.0N 118.8W 80 KT 90 MPH 72H 15/1800Z 19.0N 120.8W 75 KT 85 MPH 96H 16/1800Z 18.6N 124.5W 65 KT 75 MPH 120H 17/1800Z 18.5N 128.3W 55 KT 65 MPH $$ Forecaster Berg NNNN