Tropical Storm Polo Moving Northwest

Tropical Storm Polo continues to move northwestward parallel to the west coast of Mexico.  At 11:00 p.m. EDT on Thursday the center of Polo was located at latitude 18.4°N and longitude 106.6°W which put it about 150 miles south-southwest of Cabo Corrientes, Mexico and about 375 miles southeast of the southern tip of Baja California.  Polo was moving toward the northwest at 9 m.p.h.  The maximum sustained wind speed was 70 m.p.h. and the minimum surface pressure was 981 mb.

An upper level ridge over northwestern Mexico is producing northeasterly winds that are creating wind shear over Polo.  The wind shear is limiting thunderstorm activity on the northern side of the storm.  It is also possible that Polo is close enough to Mexico that it may be pulling some drier air into the northern half of the circulation.  Both of those factors are inhibiting intensification of Polo.

A high pressure system in the middle levels over Mexico is steering Polo toward the northwest.  The tropical storm is starting to move a little more quickly.  Numerical models are suggesting that the mid-level high will strengthen and eventually turn Polo more toward the west.  Most guidance predicts that Polo will move southwest of Baja California.  However, based on the faster motion the government of Mexico has issued a Tropical Storm Watch for a portion of southern Baja California from Santa Fe to La Paz.  A Tropical Storm Warning remains in effect for a portion of the coast from Punta San Telmo to Playa Perula.  A Tropical Storm Watch continues for the portion of the coast from Playa Perula to Cabo Corrientes.