Issued at 200 AM PDT Mon Oct 05 2026
104 WTPZ43 KNHC 050840 TCDEP3 Hurricane Rachel Discussion Number 33 NWS National Hurricane Center Miami FL EP182026 200 AM PDT Mon Oct 05 2026 Rachel has the satellite appearance of a hurricane that recently underwent an eyewall replacement cycle (ERC), with a broad ring of outer convection while the smaller core it had yesterday is decaying within. On microwave imagery, a 0302 UTC GMI pass also showed a more prominent outer eyewall that was open on the northwest side on the 89 GHz channel. This structure suggests some dry air is also being entrained into the circulation, likely due to 15-20 kt of northeasterly vertical wind shear diagnosed by UW-CIMSS. The D-MINT intensity estimate associated with that GMI microwave pass was 83 kt, but other subjective and objective satellite estimates continue to gradually decrease, so the initial intensity is being lowered to 80 kt for this advisory. The hurricane continues to move north of due west, estimated at 280/7 kt. A mid-level ridge over the southwestern United States extends into the east Pacific and is expected to continue steering Rachel off in a general westward to west-northwestward motion over the next 2-4 days. Near the end of the forecast period, a mid- to upper-level trough is forecast to dig in to the northwest of Rachel, with the guidance showing the tropical cyclone's motion coming to a halt and potentially turning northeastward by 120 h. While both the deterministic and ensemble track guidance are tightly clustered over the first 3-4 days, the possible trough interaction results in a large increase in track spread by 120 h. The latest NHC track forecast is just a touch north of the previous one, following the blend in the latest HFIP Corrected Consensus Approach (HCCA), Google DeepMind ensemble mean (GDMI), and its newer version (WN3I). The intensity forecast for Rachel is a little interesting. Part of the recent weakening is likely due to the combination of the hurricane undergoing an ERC while there was a subtle increase in northeasterly shear over the past day. Both the GFS and EC-SHIPS guidance show this shear persisting for the next 12-24 h before diminishing below 10 kt as the hurricane continues to traverse sea-surface temperatures (SSTs) in the 26-27 C range. Thus, while a little additional weakening is shown in the short-term, the hurricane might stabilize for a bit if the shear decreases, and I can't rule out the possibility it might still develop annular characteristics in the 36-48 h time frame. Thereafter, while shear will likely remain low, SSTs decrease to around 25 C, and most of the guidance responds by showing slow weakening resuming. Rachel may start to struggle to produce organized convection by 120 h. However, this is a trickier-than-usual forecast, because during that time it may also interact with an upper-level trough which could provide some baroclinic support to help maintain convection. In fact, this possibility is shown in the simulated infrared imagery from the 00 UTC GFS and ECMWF runs. Thus, post-tropical status is not shown at 120 h quite yet. The latest NHC intensity forecast lies closest to the HCCA intensity aid. FORECAST POSITIONS AND MAX WINDS INIT 05/0900Z 20.4N 115.6W 80 KT 90 MPH 12H 05/1800Z 20.5N 116.7W 75 KT 85 MPH 24H 06/0600Z 20.6N 118.2W 75 KT 85 MPH 36H 06/1800Z 20.7N 119.7W 75 KT 85 MPH 48H 07/0600Z 21.0N 121.0W 75 KT 85 MPH 60H 07/1800Z 21.5N 122.5W 65 KT 75 MPH 72H 08/0600Z 22.0N 124.1W 60 KT 70 MPH 96H 09/0600Z 22.4N 126.7W 50 KT 60 MPH 120H 10/0600Z 22.6N 126.5W 40 KT 45 MPH $$ Forecaster Papin
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