Tag Archives: Tropical Storm Marty

Tropical Storm Marty Develops South of Baja California

Tropical Storm Marty developed over the Eastern North Pacific Ocean south of Baja California on Monday morning. At 5:00 a.m. EDT on Monday the center of Tropical Storm Marty was located at latitude 20.0°N and longitude 111.0°W which put it about 210 miles (340 km) south-southwest of the southern tip of Baja California. Marty was moving toward the west at 15 m.p.h. (24 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1000 mb.

The circulation of former Hurricane Grace developed into Tropical Storm Marty south of Baja California on Monday morning. Although the surface circulation of former Hurricane Grace dissipated when it moved across central Mexico during the weekend, the circulation in the middle and upper troposphere remained intact. New thunderstorms began to form when the middle and upper parts of the circulation moved over the Eastern North Pacific west of Mexico. Downdrafts in those thunderstorms transported momentum down to the surface and a low level circulation spun up. More thunderstorms formed near the low level center on Monday morning and the National Hurricane Center designated the system as Tropical Storm Marty.

The circulation around Tropical Storm Marty was well organized. Thunderstorms near the center of Marty were generating upper level divergence that was pumping mass away from the tropical storm. Bands of showers and thunderstorms were revolving around the center of Tropical Storm Marty. Winds to tropical storm force extended out 70 miles (110 km) from the center of Marty.

Tropical Storm Marty will move through an environment somewhat favorable for intensification during the next 24 hours. Marty will move over water where the Sea Surface Temperatures are near 27°C. It will move under the southern part of an upper level ridge centered near Baja California. The ridge will produce easterly winds that will blow toward the top of Marty’s circulation. Those winds will cause vertical wind shear. The wind shear will inhibit intensification, but it will not be strong enough to keep Tropical Storm Marty from getting stronger during the next 24 hours. Marty will move over cooler water on Tuesday and there will be less energy available to the tropical storm.

Tropical Storm Marty will move south of a subtropical high pressure system over the Eastern North Pacific Ocean. The high will steer Marty toward the west during the next several days. On its anticipated track Tropical Storm Marty will move farther away from Baja California.

Elsewhere, the circulation of former Hurricane Linda was approaching Hawaii. At 2:00 a.m. EDT on Monday the center of former Hurricane Linda was located at latitude 21.0°N and longitude 154.8°W which put it about 115 miles (185 km) east of Wailuku,, Hawaii. It was moving toward the west 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 1006 mb. The circulation of former Hurricane Linda will bring gusty winds and locally heavy rain to parts of Hawaii during the next several days.

Marty Intensifies and Mexico Issues a Tropical Storm Watch

Tropical Storm Marty intensified on Sunday and the government of Mexico issued a Tropical Storm Watch for a portion of the west coast.  At 2:00 p.m. EDT on Sunday the center of Tropical Storm Marty was located at latitude 15.0°N and longitude 102.8°W which put it about 235 miles (380 km) southwest of Acapulco, Mexico.  Marty was moving toward the north-northeast at 6 m.p.h.  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 997 mb.  A Tropical Storm Watch has been issued for the portion of the coast from Acapulco to Lazaro Cardenas, Mexico.

The structure of Tropical Storm Marty improved on Sunday morning.  A long rainband stretched around the southern and eastern sides of the circulation and more thunderstorms developed near the center or circulation.  Marty is over water where the Sea Surface Temperature (SST) is near 30°C, which means there is a lot of energy in the upper ocean.  However, an upper level trough extends from the western Gulf of Mexico across northern Mexico.  The upper level trough is causing westerly winds, which could already be producing vertical wind shear over the northern half of the circulation of Tropical Storm Marty.  Very warm SSTs mean that the potential for intensification exists, but the vertical wind shear will limit how much intensification actually occurs.  If the upper level winds get stronger, they could shear the top half of the circulation away from the bottom half and cause Marty to dissipate.

The upper level trough is beginning to steer Marty toward the north-northeast and the tropical storm is likely to move in that direction over the short term.  The ultimate track of Marty will be determined by the vertical integrity of the circulation and the strength of the vertical wind shear.  If the wind shear is not too strong and the upper and lower portions of the circulation remain together, then the trough will steer all of Marty toward the northeast.  In that case it could make landfall on the Mexican coast in several days.  However, if the vertical wind shear blows then top off of the circulation, then the upper level portion will move northeast toward Mexico, while the lower part of the tropical storm is left behind.  The upper half of the circulation could still bring heavy rain and the potential for floods to parts of Mexico, even if the surface circulation does not make landfall.