The Blob (Pacific Ocean) the surface waters of the mid-latitude Pacific Ocean flipping from a cold phase to a warm phase in a cycle known as the Pacific decadal oscillation (PDO). This poorly-understood change happens at irregular intervals of years or decades. During a warm phase, the west Pacific becomes cooler and part of the eastern ocean warms; during the cool phase, these changes reverse. Scientists believe a cold phase started in the late 1990s and the arrival of the Blob may be the start of the next warm phase. The PDO phases may also be related to the likelihood of El Nino events.
Significant weather advisory broadcast television stations have begun including significant weather advisories into their systems, however, these systems usually classify such an advisory terms such as "Heavy T-Storms", "Heavy Storms" or "Strong T-Storms" (terms used by the system prior to the inclusion of the product). The National Weather Service in the United States issues a significant weather advisory for strong thunderstorms (and occasionally, other weather situations such as downbursts) that may pose limited to no threat to life and property; it is typically issued if the hail size in a thunderstorm is one-half to one inch in diameter, and/or winds of 35 to