A Pacific Hurricane Update: Hurricane Kay (2022)

Though I usually only post on Atlantic tropical cyclones, this post will describe a significant eastern Pacific tropical cyclone, Hurricane Kay.

Storm Active: September 4-9

Around September 1, a disturbance formed in the Gulf of Tehuantepec, off the Pacific coast of southeastern Mexico. The atmosphere in the region was extremely humid and ocean waters were warm, giving the system ample fuel for developement. There was some wind shear present and the disturbance was very large, so it consolidated only slowly over the next few days as it moved generally westward. Satellite imagery indicated that it developed into Tropical Depression Twleve-E around midday on September 4.

It didn't take long for the depression to strengthen into Tropical Storm Kay. Kay had quite a large radius of maximum winds and an impressive satellite signature on the southern side, with curved bands extending hundreds of miles to the south and west. However, the center of circulation was nearly exposed from under cloud cover on the northern side. The storm experienced slow and steady intensification for the next day. By September 5, Kay had managed to wrap convection nearly around its center and a partial eyewall was complete. This lead to a faster increase in winds and the storm was upgraded to a hurricane that afternoon.

Kay gradually turned toward the north over the next day. Even though the center was far from land, southern Baja California experienced intermittent gale conditions from the storm's outer bands. Later on the 6th, the cyclone developed a distinct eye. Kay reached its peak intensity of 105 mph winds and a central pressure of 967 mb early on September 7, just in time for it to encounter cooler waters. This led to a slow diminishing of deep convection near the center, and consummerate drop in winds. Nonetheless, Kay remained a formidable storm as it moved closer to the central Baja California peninsula.

By early on September 8, most thunderstorm activity south and west of the center had died off over cold water. In fact, the heaviest rain associated with Kay was in bands stretching northwestward from the Gulf of California, where the water was much warmer than on the Pacific side and supported stronger storm activity. The system was still a minimal hurricane when it made landfall midway up the peninsula that afternoon. The center of Kay moved north-northwest generally parallel to Baja California's coastline and emerged over water again as a tropical storm. By September 9, the core of the storm was just a swirl of clouds, with flooding rains continuing farther north in far northwestern Mexico and southern California. It turned west under the influence of a ridge sitting over the southwestern United States as it weakened. Later that day, it was classified as post-tropical. The remnants of Kay slowly spun down and the moisture it carried northward brought additional showers to southern California over the next couple of days. Kay was one of only a few cyclones on record to directly affect California.

The image above shows Kay at peak intensity on September 7.

Kay brought beneficial rain to Baja California, southwestern Mexico, and southern California without bringing impacts that are too severe.