Hurricane Jova slowly moved ashore over Mexico’s Pacific coast at 10 pm PDT last night as a Category 2 storm with 100 mph winds. Jova was the strongest hurricane to hit Mexico’s Pacific coast since Hurricane Jimena hit Baja as a Category 2 storm with 105 mph winds in 2009. Jova was a small storm at landfall, with hurricane-force winds that extended outwards only 15 miles from the center. Thus, only a relatively small stretch of coast saw Jova’s most dangerous winds and storm surge. A much greater concern are Jova’s rains. Satellite rainfall estimates indicate that Jova had already dumped up to six inches of rain along the coast as of 2 am EDT this morning. Jova is moving very slowly and is expected to stall out over the coast on Thursday, which will lead to extremely heavy rains over the coastal mountains of Mexico. These rains are likely to accumulate to over fifteen inches in some spots, and life-threatening flash flooding and mudslides are likely in the region of Mexico between Manzanillo and Puerto Vallarta over the next three days. Recent satellite loops show the hurricane has weakened drastically since landfall, with the eye no longer apparent and much less vigorous heavy thunderstorm activity. Jova will likely weaken to a tropical storm later today.

This year’s Eastern Pacific hurricane season has been below average for number of named storms, which is typical for a La Niña year. However, an unusual number of the named storms have become hurricanes and intense hurricanes–the reverse of the situation in the Atlantic. So far in 2011, there have been 10 named storms, 9 hurricanes, 5 major hurricanes, and an Accumulated Cyclone Energy (ACE) index of 108 in the Eastern Pacific. An average year should have had 13 named storms, 7 hurricanes, 3 major hurricanes, and an ACE index of 125 by October 12. On average, the Eastern Pacific sees just two more named storms and one hurricane after October 11.

Figure 1. True-color MODIS image of Jova taken at 3:55 pm EDT October 11, 2011. At the time, Jova was a Category 2 hurricane with 100 mph winds. Image credit: NASA.

Figure 2. Rainfall forecast for Hurricane Jova from this morning’s 2 am EDT run of the GFDL model. Image credit: Morris Bender, NOAA/GFDL.

Links to follow Jova
Wunderblogger Mike Theiss is in Barra de Navidad, just north-west of Manzanillo, and received a direct hit from Jova’s eye last night. His final report; “Found a small building north of La Manzanilla directly in path of Hurricane Jova’s eye. No power, only iPhone battery and still cell service for now. We will get a direct hit here but no lights to see anything to film. Waves are large and crashing on building. Only going to get worse !! Sorry no photos yet, today was actually nice all day and right at dark wind picked up and knocked out power.”

Puerto Vallarta webcam

Tropical Storm Irwin not expected to threaten Mexico
Tropical Storm Irwin, which is headed eastwards towards the same stretch of Mexican coast Jova is affecting, is expected to dissipate before reaching the coast. It is unlikely Irwin will bring significant rains to Mexico.

Quiet in the Atlantic
Many of the computer models continue to predict that a strong tropical disturbance capable of becoming a tropical depression could form in the Western Caribbean or extreme southern Gulf of Mexico early next week. Some of the spin and moisture for this storm could potentially come from Tropical Depression 12-E, which formed in the Eastern Pacific this morning, just offshore of the Mexico/Guatemala border. TD 12-E is expected to move inland over Southeast Mexico and Guatemala over the next few days, bringing very heavy rains of 5 – 10 inches capable of causing life-threatening flash flooding and mudslides.

Jeff Masters