Tag Archives: Tropical Storm Rosa

Tropical Storm Rosa Nears Baja California

Tropical Storm Rosa moved nearer to Baja California on Monday morning.  At 11:00 a.m. EDT on Monday the center of Tropical Storm Rosa was located at latitude 27.5°N and longitude 116.5°W which put it about 90 miles (145 km) west-southwest of Punta Eugenia, Mexico.  Rosa was moving toward the north-northeast at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1000 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Punta Abreojos to Cabo San Quintin, Mexico.  A Tropical Storm Watch was in effect for the portion of the coast from Bahia de los Angeles to San Felipe, Mexico.

Tropical Storm Rosa was weakening as it approached the coast of Baja California.  Rosa was moving over water where the Sea Surface Temperature was near 23°C.  An upper level low west of California was producing southwesterly winds which were blowing toward the top of the circulation.  Those winds were causing significant vertical wind shear.  The effects of cool water and vertical shear were causing most of the stronger thunderstorms to occur northeast of the center of circulation.  Bands south and west of the center consisted primarily of showers and lower clouds.

The center of Tropical Storm Rosa will reach northern Baja California in a few hours.  Rosa will bring some gusty winds when when it reaches the coast, but the greater risk is locally heavy rainfall.  Rosa could drop several inches of rain and flash floods could occur.  The lower level part of Rosa’s circulation will weaken when it crosses Baja California.  However, the upper low west of California will steer the middle and upper parts of Tropical Storm Rosa over the Southwestern U.S.  Rosa, or its remnants, could drop locally heavy rain over that region during the next several days.  Flash Flood Watches have been issued for southeastern California, eastern Nevada, western Arizona, and much of Utah.

Elsewhere over the Eastern North Pacific, Tropical Storm Sergio was strengthening slowly south of Baja California.  At 11:00 a.m. EDT on Monday the center of Tropical Storm Sergio was located at latitude 11.5°N and longitude 109.5°W which put it about 790 miles (1275 km) south of the southern tip of Baja California.  Sergio was moving toward the west at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 995 mb.

Tropical Storm Rosa Develops Southwest of Mexico

Tropical Storm Rosa developed southwest of Mexico on Tuesday morning.  At 11:00 a.m. EDT on Tuesday the center of Tropical Storm Rosa was located at latitude 14.7°N and longitude 108.0°W which put it about 385 miles (620 km) southwest of Manzanillo, Mexico.  Rosa was moving toward the west-northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1004 mb.

A distinct center of circulation consolidated in an area of thunderstorms southwest of Mexico on Tuesday morning and the National Hurricane Center designated the system as Tropical Storm Rosa.  An inner rainband wrapped tightly around the center.  Several other bands of showers and thunderstorms were revolving around the core of Tropical Storm Rosa.  The circulation was symmetrical and rainbands were occurring in all parts of the tropical storm.  Storms near the core began to generate upper level divergence which was pumping mass away from Rosa.

Tropical Storm Rosa will move through an environment favorable for intensification during the next several days.  Rosa 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.  Tropical Storm Rosa could intensify into a hurricane by later on Wednesday.

Tropical Storm Rosa will move southwest of a middle level ridge over northern Mexico.  The ridge will steer Rosa in a general west-northwesterly direction during the next several days.  On its anticipated track Tropical Storm Rosa will move southwest of Baja California later this week.