Andres Becomes the Farthest West Major Hurricane on Record for May in the NE Pacific

Hurricane Andres became only the fifth major May hurricane on record in the Northeast Pacific on Sunday, when it intensified into a 125 mph Category 3 storm in the waters about 800 miles southwest of the tip of Mexico's Baja Peninsula. Its unexpected intensification continued Sunday evening, with Andres reaching Category 4 strength with 140 mph winds at 11 pm EDT. According to the database of Eastern Pacific storms maintained by NOAA's Office for Coastal Management, Andres' emergence as a major hurricane at longitude 118.8°W marks the farthest west a major hurricane has been in the Northeast Pacific in May in the 45 years since accurate satellite records began in 1970, and comes well before the usual July 19 formation date of the first major hurricane of the Northeast Pacific hurricane season. This unusually early and far westerly intensification was made possible, in part, by sea surface temperatures (SSTs) that are very warm, at least 2°F (1.1°C) above average--thanks in large part to the intensifying moderate-strength El Niño event underway in the Eastern Pacific. The other May major hurricanes were Adolph (2001), Alma (2002), Bud (2012), and Amanda (2014). The strongest was Hurricane Amanda, which peaked as a top-end Category 4 hurricane with 155 mph winds on May 25, 2014. The earliest Category 5 storm on record in the Eastern Pacific was Hurricane Ava of 1973, which peaked at 160 mph winds on June 6, 1973. Both years (2014 and 1973) had ocean temperatures that were unusually warm along the path of these intense hurricanes: at least 0.4°C above average. Andres will stay well out to sea and not affect any land areas.


Figure 1. MODIS image of Hurricane Andres taken at approximately 2 pm EDT May 31, 2015. At the time, Andres was intensifying into a Category 3 storm with 125 mph winds. Image credit: NASA Worldview.


Figure 2. Tracks of all May tropical storms and hurricanes in the Eastern Pacific Ocean according to the database maintained by NOAA's Office for Coastal Management. The 2015 version of Hurricane Andres became a major hurricane on Sunday afternoon at 5 pm EDT May 31 (large orange X) farther west than any previous May major hurricane has existed in the Northeast Pacific (accurate records of Eastern Pacific tropical cyclones began in 1970.) The previous record was 115.4°W by Hurricane Alma of 2002.

Tropical Depression 2-E forms in the Northeast Pacific
Hurricane Andres now has a companion--Tropical Depression 2-E, which formed Sunday afternoon about 380 miles SSW of Zihuatanejo, Mexico. TD 2-E is suffering high wind shear due to the upper-level outflow from Hurricane Andres, but will likely see lower wind shear by Tuesday and become Tropical Storm Blanca as Andres moves off to the west. Intensification into a major hurricane is predicted by NHC by the end of the week. TD 2-E will not be a threat to any land areas this week, but it is too early to say if it will miss the coast of Mexico next week or not. The usual appearance of the second named storm of the Northeast Pacific hurricane season comes on June 25.

NOAA predicts an above-average Eastern Pacific hurricane season: 18.5 named storms
Andres and TD 2-E are the first salvos in what is likely to be a very busy Northeast Pacific hurricane season. NOAA's pre-season prediction for the Eastern Pacific hurricane season, issued on May 27, calls for 15 - 22 named storms, 7 - 12 hurricanes, 5 - 8 major hurricanes, and an ACE index 110% - 190% of the median. The mid-point of these ranges gives us a forecast for 18.5 named storms, 9.5 hurricanes, and 6.5 major hurricanes, with an ACE index 150% of average. The 1981 - 2010 averages for the Eastern Pacific hurricane season are 15 named storms, 8 hurricanes, and 4 major hurricanes.

I'll have a new post late morning on June 1--the beginning of the Atlantic hurricane season.

Jeff Masters