Amanda became the strongest May eastern Pacific hurricane on record Sunday morning as peak winds approached that of a Category 5 hurricane.
Amanda's maximum sustained winds increased to near 155 mph and its central pressure dropped to 932 millibars by 11 a.m. PDT Sunday, meaning Amanda was a very powerful Category 4 hurricane.
Amanda has continued to weaken from its peak strength, now a tropical depression, and continues to move slowly northward over the eastern Pacific.
Adolph from 2001 originally held the distinction of strongest May hurricane in the basin. At the peak of Adolph's intensity, the central pressure bottomed out at 940 millibars and winds were nearly 145 mph.
This satellite image of Amanda, courtesy of NOAA, was taken Sunday, May 25, 2014.
Amanda is also the earliest Category 4 hurricane in the eastern Pacific, ahead of Hurricane Adolph in 2001, and the second earliest major eastern Pacific hurricane on record, behind Hurricane Bud in 2012.
Adolph reached Category 4 strength on May 28, 2001.
It is unusual, in terms of climatology, to have a minimal hurricane form in the eastern Pacific in May, let alone a strong Category 4 hurricane.
Maximum sustained winds within a Category 4 hurricane range from 130 to 156 mph. On average, it takes until June 26 for the first hurricane to form in the eastern Pacific. The first major hurricane of the season typically does not form in the eastern Pacific until July 19.
There has never been a Category 5 hurricane in the eastern Pacific during May.
No hurricanes in the Atlantic have reached Category 4 strength in May. Audrey, from late June 1957, holds the record for the Atlantic's earliest Category 4 hurricane.
The warm ocean waters and a lack of strong wind shear (disruptive winds above the surface) allowed Amanda to undergo rapid intensification over the weekend. Amanda was first classified as a tropical depression Thursday afternoon.
A general weakening trend is expected to continue through the end of the week as Amanda heads into stronger wind shear and cooler water.
Amanda will remain over the open waters of the eastern Pacific, posing no direct threat to land. However, moisture from the storm could be drawn into northern Mexico, and perhaps as far north as the Southwest U.S. leading to enhanced thunderstorm activity.
Amanda is just the start of what is likely to be a busy hurricane season in the eastern Pacific.
With the onset of El Niño this summer, AccuWeather.com meteorologists expect above-normal tropical activity in the eastern Pacific this season.
AccuWeather will also be monitoring the western Caribbean and southwestern Gulf of Mexico for possible tropical development late in May and during early June.
"The western part of the Caribbean Sea is a favored area for early season tropical activity in the Atlantic basin and there is a chance a non-tropical system dips southward in this area late in the month, which could allow for some development," AccuWeather.com Tropical Weather Expert Dan Kottlowski said.
AccuWeather.com Meteorologists Courtney Spamer and Alex Sosnowski and Staff Writer Mark Leberfinger contributed content to this story.
Thunderstorms once again turn severe across the Ohio Valley and into the mid-Atlantic through Sunday night.
More summer-like conditions will return to the Boston area for a brief time before a front pushes through the region during the latter part of the weekend.
Tropical Rainstorm Matmo will bring heavy rain to Japan this weekend.
Dry weather across the western half of the country continues to spark wildfires, especially across Utah and the Northwest.
AccuWeather.com meteorologists are monitoring an area of thunderstorms east of the Philippines for potential tropical development.
Rounds of showers and thunderstorms will move through the Pittsburgh area this weekend with the threat of severe weather.