Another Gulf of Mexico Late Season Hurricane Threat

NOAA/NCEP CFS V2 Forecasts Strongest January La Nina on Record
10/16/2020, 5:34 am EDT
La Nina’s Increasing Strength Reflected in Emerging Strong Negative Pacific North America Pattern
11/02/2020, 2:17 pm EST
Show all

Tropical Storm Zeta formed in the western Caribbean Sea earlier today. Zeta is forecast to start moving northwestward tonight and reach the northern Yucatan Peninsula tomorrow night and gain hurricane intensity into the south-central Gulf of Mexico later Tuesday. The immediate environment improves and supports the forecast track and intensity. However, a shear axis and cooler northern Gulf waters plus an approaching upper trough from the west makes the central Gulf to landfall forecast very uncertain.

  

Fig. 1-2: Tropical cyclone tracks and intensity for Tropical Storm Zeta.

Discussion: Tropical Storm Zeta is located at 17.8N/83.8W or about 290 miles south-southeast of the far west tip of Cuba. Zeta is stationary with max wind 40 mph and a central pressure of 1005 MB. Forecast confidence with Zeta is LOW. A northwest track is projected early week as a mid-level anticyclone builds over Florida and into the eastern Gulf of Mexico. Waters in the western Caribbean Sea are certainly warm enough to support intensification of Zeta. NOAA (and tropical cyclone models) forecast intensification to a hurricane once Zeta is across the northern Yucatan Peninsula and into the central Gulf of Mexico. But not all models agree. Currently, there is a 50-knot shear axis across the north-central Gulf of Mexico which will have to ease significantly if Zeta is to intensify to a hurricane. The northern Gulf of Mexico SST are below the North Atlantic 81F threshold to support hurricane development therefore Zeta should be a tropical storm at landfall. NOAA and various tropical cyclone models plus the ECM (“European Model”) and GFS (“American Model”) are confident regarding the timing of landfall…Wednesday afternoon. The ECM indicates landfall on the central Louisiana coast while the GFS is slightly to the east of the NOAA 5-day forecast track. The character of Zeta once northwest of the Yucatan Peninsula is awaited to make the best landfall and forward intensity forecast.

Fig. 3: NOAA/NHC 5-day forecast track for Tropical Storm Zeta.

Fig. 4: Morning weather satellite view of the North Atlantic basin.