Sentences with phrase «active storm pattern»

Not exact matches

Usually our star follows a predictable pattern, becoming more and less active (as measured by flares, sunspots, and magnetic storms) on an 11 - year cycle.

For the entire Northern Hemisphere, there is evidence of an increase in both storm frequency and intensity during the cold season since 1950,1 with storm tracks having shifted slightly towards the poles.2, 3 Extremely heavy snowstorms increased in number during the last century in northern and eastern parts of the United States, but have been less frequent since 2000.11,15 Total seasonal snowfall has generally decreased in southern and some western areas, 16 increased in the northern Great Plains and Great Lakes region, 16,17 and not changed in other areas, such as the Sierra Nevada, although snow is melting earlier in the year and more precipitation is falling as rain versus snow.18 Very snowy winters have generally been decreasing in frequency in most regions over the last 10 to 20 years, although the Northeast has been seeing a normal number of such winters.19 Heavier - than - normal snowfalls recently observed in the Midwest and Northeast U.S. in some years, with little snow in other years, are consistent with indications of increased blocking (a large scale pressure pattern with little or no movement) of the wintertime circulation of the Northern Hemisphere.5 However, conclusions about trends in blocking have been found to depend on the method of analysis, 6 so the assessment and attribution of trends in blocking remains an active research area.

Current work1 has provided evidence of the increase in frequency and intensity of winter storms, with the storm tracks shifting poleward, 2,3 but some areas have experienced a decrease in winter storm frequency.4 Although there are some indications of increased blocking (a large - scale pressure pattern with little or no movement) of the wintertime circulation of the Northern Hemisphere, 5 the assessment and attribution of trends in blocking remain an active research area.6 Some recent research has provided insight into the connection of global warming to tornadoes and severe thunderstorms.7, 8