Природа и человек в XXI веке
1. A particularly dangerous situation (PDS) is a type of enhanced wording first used by the National Weather Service'sStorm Prediction Center in Norman, Oklahoma on certain severe weather watches. It is issued at the discretion of the forecaster composing the watch and implies that there is an enhanced risk of very severe and life-threatening weather, usually a major tornado outbreak or (much less often) a long-lived, extreme derecho event, but possibly another weather hazard. On April 24, 2011, the National Weather Service office in Memphis issued the first PDS Flash Flood Watch to highlight the threat for widespread, significant, and potentially life-threatening flash flooding due to repeated rounds of severe thunderstorms.
PDS watches are quite uncommon; less than 3% of watches issued by the SPC from 1996 to 2005 were PDS watches, or an average of 24 each year. When a PDS watch is issued, there are often more PDS watches issued for the same weather system, even on the same day during major outbreaks, so the number of days per year that a PDS watch is issued is significantly lower.
2. The first PDS tornado watch was issued by Robert H. Johns for the April 2, 1982 tornado outbreak across the southern and central Great Plains. While historically applied only to Severe Thunderstorm, Tornado, and Flash Flood watches (i.e. Severe Local Storm "polygonal" events), PDS wording could theoretically be applied to other types of weather watches (i.e., Winter Storm, High Wind, Hurricane, or Fire Weather watches) when an enhanced threat for such conditions exists.
PDS tornada watches are issued when there is a higher than normal risk of multiple strong, violent tornadoes in the watch area (usually amounting to damage consistent with EF4 or EF5 tornadoes), also including significant wind and hail damage, when in addition to tornadoes. While there are no set criteria for a PDS watch to be issued, they are usually issued when the potential exists for a major tornado outbreak. They represent about 90% of PDS watches issued
3. PDS severe thunderstorm watches are issued when there is a higher than normal risk of severe thunderstorm winds capable of major structural damage (in addition to large hail and perhaps a few isolated tornadoes), usually due to a strong and persistentderecho. These watches are very rare (an average of only two each year), as the risk for tornadoes must remain low enough to not warrant a tornado watch (a normal tornado watch would be issued if the tornado risk is significant alongside the extreme wind threat).
PDS flash flood watches are issued when there is a higher than normal risk of widespread, life-threatening. These flash flooding watches are issued by the NWS Local Forecast Offices, not the Storm Prediction Center.
PDStornado warnings are currently issued on an experimental basis by five Forecast Offices in Kansas and Missouri. The criteria for a PDS warning is when a tornado on the ground has been spotted or confirmed, or a significant tornado is expected (due to radar signatures). The intention of this experimental warning may be to replace the loosely-defined tornado emergency. These are the first warnings issued with PDS wording, and like PDS flash flood watches, are issued by local forecast offices.
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Степени сравнения наречий. Виды наречий
Наречия имеют 3 степени сравнения: положительная (начальная форма), сравнительная (сравниваются два предмета между собой) и превосходная (показывает, что предмет имеет самые лучшие характеристики).
Сравнительная степень делится на два типа в зависимости от наречия:
1.Простая форма сравнительной степени - образуется с наречиями, состоящими из одного или двух слогов. В этом случае к наречию добавляется суффикс – er. Если наречие оканчивается на –y, то –y меняется на –i, при добавлении суффикса– er.
Fast – faster
Быстро- быстрее
Late – later
Поздно- позднее
2.Сложная форма сравнительной степени – образуется с наречиями, состоящими из трех и более слогов, а также с наречиями, заканчивающимися на – ly. Перед всеми этими наречиями ставится слово more:
Easily - more easily
Легко - легче
Beautifully - more beautifully
Красиво - крас И вее
Превосходная степень делится на два типа в зависимости от наречия:
1.Простая форма превосходной степени - образуется с наречиями, состоящими из одного или двух слогов. В этом случае к наречию добавляется суффикс – est. Если наречие оканчивается на –y, то –y меняется на –i, при добавлении суффикса– est
Fast – fastest
Быстро- наиболее быстро
2.Сложная форма превосходной степени – образуется с наречиями, состоящими из трех и более слогов, а также с наречиями, заканчивающимися на – ly. Перед всеми этими наречиями ставится слово most:
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Easily - most easily
Легко – наиболее легко
Beautifully - most beautifully
Красиво – наиболее красиво
Существуют слова- исключения:
Well – better – best
Хорошо- лучше – наилучшее
Badly – worse – worst
Плохо – хуже - наихудшее
Many/ much – more – most
Много – больше - наибольшее
Little – less – least
Мало – меньше – наименьшее
Нужно запомнить, что в отличии от превосходной степени сравнения прилагательного, употребление артикля the перед превосходной степенью наречия, считается ОШИБКОЙ.