Ernesto hits the Yucatan with 85 mph winds

Ernesto is tropical storm again, after making landfall Tuesday night at 11 pm EDT just north of the Belize/Mexico border as a Category 1 hurricane with 85 mph winds. We have few good weather observations near the landfall location, though an automated weather station on Banco Chinchorro Island just off the coast of Mexico reported a minimum pressure of 979.4 mb. A personal weather station at the Margarita del Sol Costa Maya Resort recorded sustained winds of 42 mph, gusting to 49 mph, and a pressure of 988 mb in the west eyewall of Ernesto before the station failed. No other weather stations were in the eyewall, and we did not have a hurricane hunter aircraft in the storm at landfall to measure the winds, due to technical issues. Belize radar shows that Ernesto's eyewall has collapsed, but the storm has remained well-organized during its passage over the Yucatan Peninsula. Infrared satellite loops show that Ernesto's heavy thunderstorms are mainly affecting Mexico.


Figure 1. Hurricane Ernesto at 10:45 pm EDT August 7, shortly before landfall. Image credit: Belize National Meteorological Service.


Figure 2. True-color MODIS image from NASA's Terra satellite of Tropical Storm Ernesto, taken at 12:15 pm EDT August 7, 2012. At the time, Ernesto had top winds of 65 mph. Image credit: NASA.

Forecast for Ernesto
Both radar and satellite loops show that Ernesto had a south of due west (260°) motion this morning, and it is no longer clear if the storm will re-emerge over the ocean on the west side of the Yucatan Peninsula. Even if Ernesto does move out over water again, it will be very close to the coast, limiting intensification potential. The official NHC forecast still calls for Ernesto to attain Category 1 hurricane strength over the Bay of Campeche. Ernesto's main threat will be heavy rainfall threat in the mountainous regions along its path through Mexico.

92L
A tropical wave in the Eastern Atlantic (Invest 92L) is disorganized, with satellite loops showing limited heavy thunderstorm activity and a modest amount of spin at mid-levels of the atmosphere. A large amount of dry air to the west and north of 92L is interfering with development, as seen on water vapor satellite loops. Wind shear is a moderate 10 - 20 knots. None of the reliable computer models develop 92L. The GFS model predicts 92L will reach the Lesser Antilles Islands on Saturday, but the other major models show a much slower motion with no threat to the islands for at least six days. In their 8 am Tropical Weather Outlook, NHC gave 92L a 30% of developing into a tropical cyclone by Friday morning.

A tropical wave predicted to move off the coast of Africa on Thursday night is predicted to develop by both the GFS and ECMWF models.

Jeff Masters