"Although the air is dry and evaporative to an extreme, in the winter strong polar fronts from the Mediterranean can occasionally produce rain, and, in this case, snow," explained Weather.
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Xalapa National Airport is located six miles east of Xalapa, on the South side of the road Xalapa – Veracruz, and Northwest of one small lagoon. Four miles south of the airport is the hill Chavarrillo, which has 4,000 feet of elevation. The prevailing winds are from the E-SE throughout the year. Strong winds are from the North during the polar fronts season (October to May).
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Fragilariopsis kerguelensis is well preserved in the fossil record and commonly referenced as a paleoceanographic or paleoclimatic proxy. F. kerguelensis comprises the largest deposit of biogenic silica in the world (~75%) despite only accounting for 20% of global production. It is an open water species and is found in its highest abundance between the Antarctic Circumpolar Current and the Subtropical Front. This, along with its tendency to increase valve size near polar fronts, makes F. kerguelensis an ideal indicator of paleoclimate polar front or low-carbon, high-silica exporting regimes.
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Minnesota map of Köppen climate classification. University of Minnesota, Twin Cities campus Minnesota endures temperature extremes characteristic of its continental climate; with cold winters and hot summers, the record high and low span 174 degrees Fahrenheit (96.6 °C). Meteorological events include rain, snow, hail, blizzards, polar fronts, tornadoes, thunderstorms, and high-velocity straight-line winds. The growing season varies from 90 days per year in the Iron Range to 160 days in southeast Minnesota near the Mississippi River, and mean average temperatures range from 36 °F (2 °C) to 49 °F (9 °C).
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Minuano is a cold southwesterly wind that blows in the southern Brazilian state of Rio Grande do Sul and in Uruguay. It has the same name of the indigenous Minuane people in the Portuguese language (in Spanish, the name of that people is Minuán, and the same wind is called pampero in Uruguay). It is widely mentioned in the Gaúcho folklore of the region. This wind originates from cold polar fronts that come from the southwest of South America during periods of high atmospheric pressure, usually following rains caused by the shock of the cold front with warmer stationary humid air.
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Phytoplankton blooms are dominated by diatoms and grazed by copepods in the open ocean, and by krill closer to the continent. Diatom production continues through the summer, and populations of krill are sustained, bringing large numbers of cetaceans, cephalopods, seals, birds, and fish to the area. Phytoplankton blooms are believed to be limited by irradiance in the austral (southern hemisphere) spring, and by biologically available iron in the summer. Much of the biology in the area occurs along the major fronts of the current, the Subtropical, Subantarctic, and the Antarctic Polar fronts, these are areas associated with well defined temperature changes.
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Showy ladyslippers bloom during the summer in Voyageurs National Park. Daily average summer temperatures in Minnesota range from the low 70s (22 °C) in the south to the mid 60s °F (19 °C) in the north. Because summer time air masses are not as volatile as in the winter, daily high and low temperatures rarely vary more than 15 degrees (7 °C) either side of normal. While summertime around much of the country means long stretches of hot and humid weather, Minnesota is located far enough north where periods of cooler, drier polar air frequently move in behind polar fronts dropping south from Canada.
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The polar highs are areas of high atmospheric pressure around the north and south poles; the north polar high being the stronger one because land gains and loses heat more effectively than sea. The cold temperatures in the high pressure (a process called subsidence), just as the warm temperatures around the equator cause air to rise to create the low pressure intertropical convergence zone. Rising air also occurs along bands of low pressure situated just below the polar highs around the 50th parallel of latitude. These extratropical convergence zones are occupied by the polar fronts where air masses of polar origin meet and clash with those of tropical or subtropical origin.
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Near the equator, increased cloudiness is due to the presence of the low-pressure Intertropical Convergence Zone (ITCZ) where very warm and unstable air promotes mostly cumuliform and cumulonimbiform clouds. Clouds of virtually any type can form along the mid-latitude convergence zones depending on the stability and moisture content of the air. These extratropical convergence zones are occupied by the polar fronts where air masses of polar origin meet and clash with those of tropical or subtropical origin. This leads to the formation of weather-making extratropical cyclones composed of cloud systems that may be stable or unstable to varying degrees according to the stability characteristics of the various airmasses that are in conflict.
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Sibéria brasileira no sul do Brasil ("Brazilian Siberia in the South of Brazil"), Fantástico, July 18, 2006. There are frosts south of the Tropic of Capricorn during the winter (June–September). Although most of Brazil lies in the tropics, more than 60 percent of the country's population live in areas which are cooled either by altitude, sea winds or polar fronts. While the coastal cities of Rio de Janeiro, Recife and Salvador can get extremely hot, plateau cities such as São Paulo, Brasília and Belo Horizonte have mild climates, and the southern cities of Porto Alegre and Curitiba have mild winters, but while Curitiba has a warm summer due to the average elevation of , Porto Alegre has a hot summer, with an average elevation of only .
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In January 2011, the North suffered an unusual drop in temperatures due to intense polar fronts that damaged thousands of hectares of crops in the states of Sonora, Sinaloa, Chihuahua and Durango. Temperatures generated such anomalies were the lowest recorded in the last 20 years. The situation was serious because the states of Sonora and Sinaloa received damage themselves jeopardized the supply of corn in the rest of the country, and therefore the price. That is why it was considered a great success reseeding of about 300 thousand hectares of corn and a hundred thousand of sorghum in those states, both measurable success by the number of hectares of crops and restored by the time that the problem was solved (only one month).
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San Giorgio a Cremano, as with the rest of Naples is located at 40°N facing the Bay of Naples on the west side of the Italian peninsula. This location gives the region a typical Mediterranean climate with mild, wet winters caused by the outer edges of polar fronts, and warm to hot, dry summers, due to the domination of the subtropical high pressure systems, according to the Köppen classification (Csa/Csb). The west coast tends to be slightly wetter than the east coast, with the southern 'Sirocco' wind bringing higher humidity and precipitation. The proximity of the Bay of Naples sometimes moderates high summer temperatures with off-shore breezes, although temperatures in excess of 30°C are common in summer months, and July tends on average, to be the hottest month of the year.
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The Zonda wind is produced by the northeastward movement of polar fronts, and although is hot and dry at the low-lands, it is the main mechanism for snow precipitation at the high altitude chains, where it looks as viento blanco, reaching speeds sometimes over 200 km/h. Thus, instead of being a snow-eater, this wind is particularly important for this arid region, as it is connected to the buildup of the winter snow cover and accumulation over the scarce local glaciers. According to studies (conducted over the period 1967–1976), the Zonda wind most commonly starts during the afternoon (between 12 and 6 PM), and tends to last between 1 and 12 hours, though it may present itself intermittently for as long as 2 or 3 days. It is countered usually by the entrance of cold air masses moving northwestward (viento sur).
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