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Updated September 17, 2005: Regardless how much some people may wish to blame some large natural phenomenon such as El Nino or Global Warming for a disaster such as has ocurred to New Orleans as a result of Hurricane Katrina, this hurricane was nothing out of the ordinary for this season at that location. What was unnatural was for so many people to live that far below water level that close to such a huge river and the ocean. If a hurricane hadn't done this, sooner or later a tsunami or a flood from upstream would have. It may also be easy to blame the current city, county, state, and federal authorities for the failure to avoid or even prepare for this disaster, but none of their predecessors avoided or prepared for it, either. For that matter, what did the people themselves do to avoid or prepare for it? El Niño's effects have turned farther to the north, bringing warmer than usual weather to Alaska, and allowing drier southern contintental influences to dominate the western United States, with widespread warmer conditions, and drier than usual conditions in the southern Rockies. As Winter arrives and Spring approaches, precipitation may come to resemble the norms for that time of year, but unusually warm weather will continue, and will become even stronger in the southwest. Updated December 27, 2004: The current winter season is somewhat reminiscent of the El Nino seasons of 1994. A cyclonic pattern, which would normally be located further south, has stabilized its location off the coast of California. This pattern tends to bring repetitious instability showers to the coast, monsoon-like moisture across the southwest and gulf states, and warmer than usual temperatures across most of the western states. Meanwhile, moisture that would normally be directed toward the northwest is shifted to southern Alaska, leaving the northwest drier than usual. As Spring arrives, temperatures and precipitation may come to resemble the norms for that time of year, but by that time, the northwest and northern Rocky Mountain states will have lost most opportunities for the bulk of their usual rain and snow, leaving them with drought conditions. Updated August 17, 2004: Hints of El Nino have appeared in the southern Pacific Ocean. If indeed, an El Nino occurs, it may counteract existing patterns of unusually widespread above normal temperatures and below normal precipitation occurring within the western United States. As Autumn arrives, above normal temperatures should disappear from the northwest and concentrate within the southwest, while precipitation generally becomes more normal. As winter sets in, El Nino could bring drier than usual conditions to the northern Rocky Mountains. Updated December 15, 2003: El Nino and La Nina remain silent, and the region of warmer than usual temperatures has expanded across the southeastern states, even though it remain strongest in the southwest United States. Drier than normal conditions now favor Florida and the eastern gulf coast. Wetter than usual weather has arrived in the Pacific northwest, including the northern California coast, and the western gulf coast and as far inland as Oklahoma. Warmer than usual weather will withdraw form the southeast, but will expand northward into Canada and eastward as far as the western great lakes while increasing in intensity in the southwestern states, especially in northern Arizona and nearby regions by late winter. This will recede to the west of the plains as spring arrives, but will remain intense in the southwest. As winter sets in, drier than usual conditions will appear in California, pushing the northwest's wetter weather further north. The region of wetter weather in Texas will eventually drift away into Mexico early in the spring. Updated August 7, 2003: El Nino and La Nina are currently silent, allowing the region of warmer than usual temperatures to fluctuate in size and strength, but remain centered in the southwest United States. Drier than normal conditions remain centered around the Great Basin. The region of warmer than usual temperatures will eventually increase and spread along the northern Pacific coast including Alaska, and along the Mexican border and Gulf coast, but a gap between the two will allow more normal temperatures between the them. As the southerly winds carrying the warmth into Alaska return, colder than usual weather will occur in the northern plains by the end of winter. Drought conditions will disappear from the western states by winter, replaced by more typical precipitation patterns, with periods of wetter than usual weather possible in the northwest, Rocky Mountains, and the south by spring.
Another Unique Gift Idea for KidsUpdated April 22, 2003: El Nino continues to bring warmer than usual temperatures to most of the United States, but now especially along the Mexican border and Gulf of Mexico. Jet streams bringing moisture from unusually warm parts of the Pacific Ocean temporarily favor wetter than usual weather for the northern Pacific coast, including Canada and southern Alaska. These jet streams continue diverging to the north and south near the coast, strongly encouraging unstable air there, causing more than usual moisture to fall along the coast, leaving more normal precipitation for inland areas. However, as El Nino progresses northward, the moist jet streams will leave the Pacific coast behind and focus farther north into Alaska. This will allow warmer than usual temperatures to increase and spread, and drier conditions to develop in the western states, especially around the Great Basin.
Updated December 18, 2002: A full-blown El Nino effect continues, now beginning to bring warmer than usual temperatures to the northern United States, especially between the Rocky Mountains and the Great Lakes. Jet streams bringing moisture from unusually warm parts of the Pacific Ocean bring potentially wetter than usual weather to the Pacific coast, except in the northwest. This jet stream is diverging to the north and south near the coast, strongly encouraging unstable air there, causing most of the moisture to fall along the coast, leaving less than usual for the mountains inland. Drier than usual weather in the northwest states, and particularly in the Rocky Mountains will decrease and move westward. Drier than usual weather around the Great Lakes will intensify and move toward the eastern seaboard. Tropical moisture in the south has intensified and will spread westward to include the Pacific southwest.
Updated July 13, 2002: A full-blown El Nino is in effect, bringing warmer than usual temperatures to the southern United States, but especially in the southwest and inland Pacific coastal states. Lower pressures generated by inland heat draws marine air and fog onshore along some coasts, making the weather unusually damp and cool. Otherwise, the El Nino effect encourages drier than usual weather in the northwest states, and more than usual tropical moisture in the southwest and midwest states.
Updated January 6, 2002: A new La Nina effect is combining Wind and Ocean currents bringing the potential for slightly warmer than usual weather along the Pacific coast and across the southern half of the United States. This effect should eventually spread up the coast to Alaska. a local region of drier that usual weather in central California should subside.
Updated September 4, 2001: Southeasterly wind patterns once again encourage warmer than usual temperatures from eastern California eastward across the U.S., especially along the Mexican border, as far as Texas and Oklahoma. More or less normal conditions seem to be favored elsewhere in the west.
Updated February 3, 2001: Southeasterly wind patterns continue to encourage warmer than usual temperatures from southern California eastward across the U.S., especially along the Mexican border, and drier than usual weather in the southwest. More or less normal conditions seem to be favored elsewhere.
Updated December 22, 2000: The La Nina effect has been tentatively rebuilding in the western Pacific Ocean, but with little effect for North America so far, and is expected to weaken. Regional climate patterns favoring low pressure troughs near southern California encourage cooler than usual weather along the southern coast, and warmer than usual weather in southeastern California and eastward into Arizona, New Mexico, and beyond. This effect may shift westward, removing the cooling effect from the coast. Patterns favoring high pressure near the Pacific Northwest will encourage slightly cooler than usual weather between the Cascade Mountains and the northern Rocky Mountains. This will also encourage wetter than usual weather in the Pacific Northwest and southern Idaho to end. These patterns don't seem to particularly favor wetter or drier than usual weather. However, the two pattern may come into conflict in Nevada and Utah, encouraging instability showers and thunderstorms.
Updated October 15, 2000: The La Nina effect has faded into "La Nada", a term now used to describe a lack of El Nino or La Nina influence. While this occurs, forecasting relies more heavily on weaker regional and local influences, as well as longer and shorter term influences, and becomes less certain as a result. Yes, El Nino and La Nina actually made it easier to forecast weather trends, as long as forecasters paid proper attention to them. As Autumn progresses, the southwest, especially around the southern Colorado River, has become increasingly warmer and drier than usual. Slightly wetter than usual weather has been pushed further north and east into the Rocky Mountains. As Winter approaches, slightly wetter than usual weather will also occur from the Columbia River, northward.
Updated September 4, 2000: The La Nina effect remains weak, so most of the southwest remains slightly warmer than usual, but especially in the area around Las Vegas. Wetter than usual weather continues over much of Arizona, New Mexico, and Colorado. Slightly drier than usual weather is being experienced in Oregon and surrounding areas.
Updated May 25, 2000: The La Nina effect appears to continue decreasing, so that the wetter than usual weather which had been in the northwest has migrated to northern California. This decrease has also allowed almost the entire nation to become slightly warmer than usual, with noticeably warmer weather in the desert southwest from southern Nevada into the Gulf of California. As Summer begins and progresses and La Nina fails, Unusually wet weather should disappear from the Pacific coast entirely, while the unusual heating of the Gulf of California encourages more than the usual amounts of tropical moisture to spread northeastward from there into Arizona and New Mexico and areas nearby. This pattern is somewhat reminiscent of El Nino, but it's a bit too early to be certain.
Updated March 30, 2000: La Nina continues to encourage slightly warmer than usual temperatures east of the Sierra Nevada and drier than usual weather southward from the Grand Canyon. This effect will decrease, allowing slightly warmer than usual temperatures to increase and spread throughout the region while the wetter weather withdraws to the northwest states and the drier weather moves to eastern Arizona, New Mexico, and especially The Plains.
Updated December 23, 1999: The effect of La Nina has weakened some in the western U.S. as the official beginning of winter arrives, but this is expected to be temporary, with La Nina strengthening again after January. Until La Nina's effect strengthens, typical winter-time weather patterns may be expected over much of California and Nevada, and some other areas nearby, except for cooler than normal weather along the north and south coast. Weather over Oregon, Washington, Montana, and northern Idaho are expected to remain wetter than normal, and become colder than normal. Drought conditions have weakened but continue in Arizona and New Mexico. As La Nina regains strength, wetter than normal weather should spread slightly, and the southern drought should intensify and spread farther.
Updated October 24, 1999: La Nina continues to dominate weather patterns of the Pacific coast this autumn, and is expected to continue at least through early winter. This means that weather will be somewhat erratic, but a region of high pressure off the coast will encourage subtropical moisture to encounter winter storms approaching the northern coast, while discouraging tropical storms from forming near the Mexican coast and approaching California from the south. This is expected to bring wetter than usual weather to the Pacific Northwest, hotter and drier than usual weather to the southern deserts, and slightly cooler than usual weather to the southern coast.
Updated August 21, 1999: La Nina's influence continues to dominate weather in and near California, pushing tropical moisture and heat approaching from the Gulf of California further eastward, but occasionally allowing sub-arctic moisture to approach from the Gulf of Alaska. These effects will generally increase as autumn begins, bringing cooler and wetter weather to the coast, especially in the northwest. A southeasterly flow, from central Mexico, may bring hotter and drier weather to the southern deserts.
Updated July 20, 1999: So far, midsummer has seen a strong influence of La Nina, alternating hot dry weather with brief periods of thunderstorm activity, including a storm which recently produced, "tornado-like", winds which caused damage in several areas. The future of this La Nina's influence is uncertain, with some climatologists predicting that it will continue this winter, while others claim that it is already dissipating. Downstrike expects winter-type weather to arrive early, but to have extended gaps during which milder weather will dominate.
Updated May 13, 1999: Although we are only about a month shy of the beginning of Summer, the Spring Thaw has not properly occurred, due to consistently unseasonably cool weather. Periods of warmer temperatures, up to about 80 degrees Fahrenheit in the mountainous areas of California, have been limited to the brief southerly wind flows which occur ahead of cold fronts which bring longer-term cooling afterward. This is the result of the jet stream bringing most of our weather from the Gulf of Alaska since Spring began. Cold fronts from the Gulf of Alaska are beginning to encounter stronger resistance from high pressure in the California area and are encountering less moisture from subtropical sources, which is normal for this time of year, but is being augmented by the effect of La Nina. On the other hand, La Nina is also allowing these cold fronts to persist past their normal season, so weather along the north coast will be wetter and cooler for at least part of this summer, but drier elsewhere. La Nina will inhibit the formation of monsoons in the Gulf of California, causing weather in southern California to be hotter and drier than usual, for at least part of the Summer. Although cooler air masses arriving from the northwest may have limited moisture in them, the cooler air will create instability as it passes over land which has been heated by the summer sunshine, leading to unusually frequent thunderstorm activity in northern California, especially in mountainous areas. Drought has not yet begun so far this year, and is not likely this Summer, in northern California, due to the unusual snow pack which remains in the mountains. As unusually hot and dry conditions occur in southern California, the snow pack may melt rapidly, with periods of flooding possible, with the possibility of drought beginning afterward.
Updated April 6, 1999: So far, this winter has not lived up Downstrike's expectations. Although the weather was quite dry during December and January, with a major cold spell during December which ruined much of California's orange crop, the weather became milder and wetter by February. This shows significant fluctuations in the factors controlling our climate, with the major players being a mostly maritime polar airflow in December and maritime subtropical airflow in February. Downstrike now believes that such fluctuations are likely to continue this year, starting with a more continental influence in March. This should bring relatively drier weather in all but the northwestern edge of California, with temperatures remaining unusually mild in most areas. This influence should continue into April.
Entered September 4, 1998: Downstrike suspects that drought is already returning to California. Although a major upper-level low pressure system is bringing thunderstorms to much of the state as Downstrike writes this, many of them are producing dry lightning due to hot and dry surface and mid-level conditions. Most other storm systems we have had this summer, have simply fizzled. This is very reminiscent of the weather of 1972, 1977, 1987, 1992, and 1994. These very dry years were offset by very wet years either directly before or following, if not both. Downstrike observed this trend without ever hearing about El Nino, until 1986, much less about La Nina, until 1997. During these observations, when there were two wet years back-to-back, as we have just had, they were followed by at least two dry years, with at least one displaying extreme temperatures. So Downstrike expects as much this time as well. Downstrike also observed that years of extreme temperatures follow similar patterns. So that, while 1997 saw mostly normal temperature ranges, 1998 first saw extremely mild winter temperatures, followed by extremely hot summer temperatures. This is very reminiscent of 1987 and 1988, which were followed by extremely cold winter temperatures in 1989. So Downstrike expects something similar for 1999. These patterns should combine to make 1999 a drought year with very cold winter weather, similar to what occurred in 1972 - in California and adjoining areas. Downstrike hasn't had the opportunity to grow up in another area and observe the climatary patterns there, so wouldn't presume to predict them. Isn't Downstrike's neck stretched out far enough already? |
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