Sentences with phrase «heavy precipitation trends»

Moreover, local heavy precipitation trends may not accurately reflect changing patterns happening at a larger, regional level.

The flooding continued the heavy precipitation trend of 2010, which was the wettest year on record.

Not exact matches

With flooding in parts of the Mississippi Valley and a strong Pacific storm coming into the Northwest, we examined the trend in the number of days each year with heavy precipitation at 244 individual sites in the U.S..

However, combined measuring stations around the world suggest there has been a global trend towards more frequent and intense hot extremes since the 1950s, as well as more heavy precipitation events.

These variability trends indicate that the frequency of extremes (more drought events and more heavy precipitation events) has increased whereas the mean has remained approximately the same.

This apparent inconsistency says little about the overall trend in the heaviest precipitation events, but a lot about the weaknesses of single - point measurements for detecting trends in extreme precipitation.

As a consequence, even in regions or states where there is a strong increasing trend in heavy precipitation, the trend at an individual precipitation gauge that represents the official total for a city may be equivocal, flat, or even down.

Percent changes in the amount of precipitation falling in very heavy events (defined as the heaviest 1 percent of events) from 1958 to 2012 show a clear national trend toward a greater amount of precipitation being concentrated in very heavy events.

Of course, many individual locations show strong increasing trends in the heaviest precipitation events.

Snowfall varies across the region, comprising less than 10 % of total precipitation in the south, to more than half in the north, with as much as two inches of water available in the snowpack at the beginning of spring melt in the northern reaches of the river basins.81 When this amount of snowmelt is combined with heavy rainfall, the resulting flooding can be widespread and catastrophic (see «Cedar Rapids: A Tale of Vulnerability and Response»).82 Historical observations indicate declines in the frequency of high magnitude snowfall years over much of the Midwest, 83 but an increase in lake effect snowfall.61 These divergent trends and their inverse relationships with air temperatures make overall projections of regional impacts of the associated snowmelt extremely difficult.

Observed U.S. trends in heavy precipitation (Kunkel et al. 2013)

Projections of future climate over the U.S. suggest that the recent trend towards increased heavy precipitation events will continue.

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.

This trend is driven by daily highs and lows, availability of water and heavy precipitation in a single day.

While there has been a recent increase in the number of landfalling US hurricanes, the increase in tropical cyclone - associated heavy events is much higher than would be expected from the pre-1994 association between the two, indicating that the upward trend in heavy precipitation events is due to an increase in the number of heavy precipitation events per system.

The widespread trend of increasing heavy downpours is expected to continue, with precipitation becoming less frequent but more intense.13, 14,15,16 The patterns of the projected changes of precipitation do not contain the spatial details that characterize observed precipitation, especially in mountainous terrain, because the projections are averages from multiple models and because the effective resolution of global climate models is roughly 100 - 200 miles.

There is a clear national trend toward a greater amount of precipitation being concentrated in very heavy events, particularly in the Northeast and Midwest.

Many climate studies assess trends and projections in heavy precipitation events using precipitation percentile (or quantile) indices.

... «stations experiencing low, moderate and heavy annual precipitation did not show very different precipitation trends,»... «deserts / jungles are neither expanding nor shrinking due to changes in precipitation patterns.»