Tropical Storm Andres Forms in the Northeast Pacific; Not a Threat to Mexico

By Jeff Masters
Published: 02:43 PM GMT die 28o May, anno 2015

The Northeast Pacific's first named storm of 2015 is here. Tropical Storm Andres formed at 11 am EDT on Thursday, in the waters about 690 miles southwest of Manzanillo, Mexico. The first named storm of the Northeast Pacific hurricane season usually forms by June 10, so we are nearly two weeks ahead of climatology. According to the database of Eastern Pacific storms maintained by NOAA's Office for Coastal Management, the formation of a tropical storm in May in the Eastern Pacific is not uncommon, though--33 named storms have formed in May in the 45 years since accurate satellite records began in 1970. Sea surface temperatures (SSTs) are unusually warm in the region, at least 2°F (1.1°C) above average, thanks in large part to the intensifying El Niño event underway in the Eastern Pacific. Andres will likely be able to take advantage of these warm waters and become a hurricane this weekend, but the storm will stay well out to sea and not affect any land areas for at least the next five days.

Figure 1. Latest satellite image of Andres.

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. Accurate records of Eastern Pacific tropical cyclones began in 1970. The 2015 version of Tropical Storm Andres formed in a typical location for a May tropical storm.

NOAA predicts an above-average Eastern Pacific hurricane season: 18.5 named storms
Andres is the first salvo 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.

Guest forecaster at the NHC: President Obama
Sharp-eyed readers may have noticed an unexpected name at the bottom of this morning's NHC discussion of Tropical Storm Andres. Signing the forecast discussion, along with forecaster Dan Brown, was President Barack Obama. The president visited NHC this morning to receive the annual presidential briefing on the upcoming hurricane season. This was the first time Obama was onsite at NHC for the briefing. Pictured at right: NHC director Rick Knabb, President Obama, NHC/TAFB chief Hugh Cobb, Secretary of Commerce Penny Pritzker, and NOAA Administrator Kathryn Sullivan.

Jeff Masters

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About The Author
Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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