Monthly Archives: October 2020

Tropical Depression 25 Forms over Northwest Caribbean

Tropical Depression Twentyfive formed over the Northwest Caribbean Sea on Friday morning.  At 11:00 a.m. EDT on Friday the center of Tropical Depression Twentyfive was located at latitude 18.1°N and longitude 84.7°W which put it about 220 miles (355 km) southeast of Cozumel, Mexico.  The depression was moving toward the northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1005 mb.

A Tropical Storm Warning was issued for the portion of the coast from Punta Herrero to Cabo Catoche, Mexico.  Tropical Storm Watches were issued for the portions of the coast from Punta Herrero tp Puerto Costa Maya and from Cabo Catoche to Dzilam, Mexico.

A distinct center of circulation was evident in satellite imagery within a broader area of low pressure over the Northwestern Caribbean Sea on Friday morning and the National Hurricane Center designated the system as Tropical Depression Twentyfive.  The government of Mexico issued a Tropical Storm Warning and Tropical Storm Watches for parts of the coast of the Yucatan Peninsula.

More thunderstorms were forming near the center of Tropical Depression Twentyfive.  Bands of showers and thunderstorms were revolving around the center of the depression.  Storms near the center of circulation started to generate upper level divergence which pumped mass away from the depression.

Tropical Depression Twentyfive will move through an environment favorable for intensification during the next 24 hours.  The depression will move over water where the Sea Surface Temperature is near 30°C.  It will move under an upper level ridge over the Northwestern Caribbean Sea.  The upper level winds are weak in the middle of the ridge and there will be little vertical wind shear.  Tropical Depression Twentyfive is very likely to strengthen into a tropical storm during the next 12 to 24 hours.  It could strengthen to a hurricane within 36 hours.

Tropical Depression Twentyfive will move around the southwestern part of a subtropical high pressure system over the western Atlantic Ocean.  The high will steer the depression toward the northwest during the next 24 to 36 hours.  On its anticipated track Tropical Depression Twentyfive could approach the Yucatan Coast on Saturday.  It will likely be a tropical storm when it approaches the coast, but it could strengthen into a hurricane by that time.  A reconnaissance plane was on its way to investigate the depression and that will provide more information about its structure and intensity.

Marie Strengthens into a Major Hurricane

Hurricane Marie strengthened into a major hurricane on Thursday.  At 11:00 p.m. EDT on Thursday the center of Hurricane Marie was located at latitude 15.6°N and longitude 122.1°W which put it about 940 miles (1515 km) west-southwest of the southern tip of Baja California.  Marie was moving toward the west-northwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 957 mb.

The circulation around Hurricane Marie was very well organized on Thursday night.  There was a small circular eye with a diameter of 12 miles (19 km) at the center of Marie.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Hurricane Marie.  Storms near the core were generating strong upper level divergence which was pumping mass away from the hurricane in all directions.  Winds to hurricane force extended out 20 miles (30 km) from the center of Marie.  Winds to tropical storm force extended out 125 miles (200 km) from the center.

Hurricane Marie will move through an environment favorable for intensification during the next 24 hours.  Marie will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Marie is likely to strengthen on Friday.  If a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could begin which would cause Marie to weaken.  Hurricane Marie will move over cooler water during the weekend.  Marie will extract less energy from the ocean which will cause the wind speed to decrease.

Hurricane Marie will move south of a ridge of high pressure over the southwestern U.S. and Eastern North Pacific Ocean.  The high will steer Marie toward the west-northwest during the next several days.  On its anticipated track Hurricane Marie will move farther away from Baja California.