The event devastated the Southwest, shifting a densely forested landscape to one primarily covered with fast-growing herbs and ferns. The North American monsoon, variously known as the Southwest monsoon, the Mexican monsoon, the New Mexican monsoon, or the Arizona monsoon is a pattern of pronounced increase in thunderstorms and rainfall over large areas of the southwestern United States and northwestern Mexico, typically occurring between June and mid-September.During the monsoon, thunderstorms are fueled by daytime heating . Figure by climate.gov; data from CPC Unified data. | View Google Privacy Policy. Southwest Increased heat, drought, and insect outbreaks, all linked to climate change, have increased wildfires. Raucous summer thunderstorms characteristic of the monsoon season are spotty, while drizzly winter storms last longer and engulf large portions of the region. For many of us, the word monsoon conjures images of heavy rain lasting for months. Sci. Record high temperatures for the Southwest range from 53C (128F) in Arizona to 47C (117F) in Utah, while record low temperatures range from 56C (69F) in Utah to 40C (40F) in Arizona. Figure by climate.gov. Copyright 2021 Paleontological Research Institution. There is some variability in the onset and demise of the monsoon. Reconstruction created using basemap from the PALEOMAP PaleoAtlas for GPlatesand the PaleoData Plotter Program, PALEOMAP Project by C. R. Scotese (2016); map annotations by Jonathan R. Hendricks for PRI's[emailprotected]project (CC BY-NC-SA 4.0license). Thus, each Southwestern state experiences both extreme highs and lows. While the state is generally arid, its high western mountains experience more precipitation each year than the desert southwest and the high northeastern plateau do. People in the Southwest are particularly dependent on surface water supplies like Lake Mead, which are vulnerable to evaporation. Image adapted from an image by Scenarios for Climate Assessment and Adaptation, first published in The Teacher-Friendly Guide to the Earth Science of the Southwestern US. Warm, moist air from the south occasionally but infrequently moves into Colorado during the summer. Left imageandright imageby NickLongrich (Wikimedia Commons,Creative Commons Attribution-ShareAlike 4.0 International license, images cropped and resized). To provide more detailed information, each state has been divided into climate divisions, which are zones that share similar climate features. Scale bar = 1 centimeter (about 0.4 inches). Record high temperatures for the Southwest range from 53C (128F) in Arizona to 47C (117F) in Utah, while record low temperatures range from 56C (69F) in Utah to 40C (40F) in Arizona. Trees killed by bark beetles at Cameron Pass, Colorado, 2011. Yet this landscape actually supports a vast array of plants and animals, along with millions of people who call the Southwest home. Source:FEMA National Risk Index. In the middle Cretaceous, oceans covered most of the Southwest, with the exception of parts of Arizona and New Mexico. Ordovician deposits across the Southwest indicate warm, shallow seas rich in invertebrate life. Saguaro and cholla cacti in the Sonoran Desert National Monument, Arizona. Photo credits: 1916 photo from USGS (public domain), 2013 photo by daveynin (flickr,Creative Commons Attribution 2.0 Generic license, image resized). A shift in plant type to those better adapted to drier conditions further suggests a change in climate during the Permian. After the end-Cretaceous bolide impact, the climate may have cooled briefly, but it soon rebounded to a warmer state. By 2070, one can expect up to 38 more days of freeze-free weather each year. Changes include formatting and revisions to the text and images. Later in the Jurassic, the climate became more moderate; dune fields were replaced by rivers and floodplains populated by a rich dinosaur fauna (exemplified by the Morrison Formation) and large trees along rivers, streams, and grasslands. Large portions of the Southwest have experienced drought conditions since weekly Drought Monitor records began in 2000. Layers of gypsum, an evaporate, from the Permian Castile Formation, Eddy County, New Mexico. Earth 300 million years ago, during the end of the Carboniferous Period (Pennsylvanian). In New Mexico, for example, average annual precipitation ranges from less than 25 centimeters (10 inches) within the Great Plains and Basin and Range regions to more than 50 centimeters (20 inches) at the higher elevations to the northwest. In winter, daily temperatures in the southwest are cooler with highs in the 50s and 60s F, and lows in . In chapter 8.3, How is the water cycle changing and why?, the report states In summary, both paleoclimate evidence and observations indicate an intensification of the NAmerM in a warmer climate (medium confidence). The globe about 485 million years ago, near the Cambrian-Ordovician boundary. Andrews Glacier in Rocky Mountain National Park, Colorado, at two points in time. Photo by James St. John (flickr, Creative Commons Attribution 2.0 Generic license, image resized). The intensification recorded since about the 1970s has been partly driven by greenhouse gas emissions (medium confidence). In 8.4, What are the projected water cycle changes?, the summary statement is there is low agreement on a projected decrease of NAmerM precipitation, however there is high confidence in delayed onsets and demises of the summer monsoon.. Resilient Bermudagrass is widely used in the region, but sufficient watering is essential in the desert climate . In the latest Cretaceous, sea level dropped again and the western Southwest became a broad coastal plain that hosted lush forests, abundant dinosaurs, and large swamps. Right:Reconstruction of living animals. The current drought outlooks expect that the drought in Arizona and New Mexico will improve in the short term, but persist. Left:Trilobites identified asDolichometoppus productusandAlokistocare althea. Dry conditions are common throughout the Great Plains, Colorado Plateau, and Basin and Range. Mesohippusmeasured up to 70 centimeters (2 feet) at shoulder height. Notice that North America has separated from Africa and there is a spreading center in the Central Atlantic Ocean. Modified from illustrations by Wade Greenberg-Brand originally published inThe Teacher-Friendly Guide to the Earth Science of the SouthwesternUS. Map of the modern Yucatn Peninsula region showing the location of the Chicxulub impact crater. Data for Figure 2 were provided by the National Drought Mitigation Center. Moisture condenses out of the warm air as it comes into contact with cool air, forming clouds. Average Annual Temperatures in the Southwestern United States. That timeworn classic is only partially true--May and September can also be great summer months. (2) In fact, comparing 1955, a year with very similar total rainfall in Tucson as this year, to this year shows temperature between July 1 and August 23 were on average more than 2 degrees F warmer. All of these plants, animals, and people need water to survive. The thicker line is a nine-year weighted average. This planting zone combines saline water and alkaline soil with intense sunlight, high temperatures and varying elevations. On the other hand, New Mexico and northern Mexico are near or a bit below average. The long-range forecast team breaks down region by region what to expect during the summer. The coldest periods will be in late November, mid- and late December, and mid-January. The pyrocumulonimbus cloud shown at the arrow was created by heat from the fire. Acad. Water supply is an important issue in the Southwest, and communities will need to adapt to changes in precipitation, snowmelt, and runoff as the climate changes. Summer rains fall almost entirely during brief but intense thunderstorms on the Great Plains, although the occasional hurricane in the Gulf of Mexico may push heavier precipitation inland. Large lakes covered parts of northern Utah and Colorado. Since 800,000 years ago, an equilibrium has been reached between warming and cooling, with the ice caps growing and retreating primarily due to the influence of astronomical forces (i.e., the combined gravitational effects of the Earth, Sun, moon, and planets). One controversial hypothesis proposes that an area of western Coloradoone of the islands that dotted the early Carboniferous seawas, in fact, glaciated. Thanks for visiting the North American Monsoon region with me! A large, low-latitude desert formed along Pangaea's western margin, generating extensive dune deposits. Bark beetles, which normally die in cold weather, have been able to survive through the winter and reproduce, increasing tree mortality. Higher atmospheric moisture content has also been correlated with an increased incidence of tornados and winter storms. By comparison, the average high and low temperatures for the entire United States are 17C (63F) and 5C (41F), respectively. SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS. Photo by Eltiempo10 (Wikimedia Commons, Creative Commons Attribution-ShareAlike 4.0 International license, image resized). In the Southwest, climate change may impact a variety of resources, including water availability in the form of snowpack and spring streamflow, the distribution and composition of plant communities, and fire regimes. Las Cruces is located in the Basin and Range region of New Mexico. Every part of the Southwest experienced higher average temperatures between 2000 and 2020 than the long-term average (1895-2020). Copyright 2021 Paleontological Research Institution. Maps showing the progressive closure of the Isthmus of Panama at 20 million years ago (A) and 15 million years ago (B). Carbon dioxide emissions in Arizona rose through the last three decades of the 20th century and reached a peak in 2008. Photo by Stefan Klein (Wikimedia Commons, Creative Commons Attribution-ShareAlike 4.0 International license, image cropped and resized). Photo by James St. John (flickr,Creative Commons Attribution 2.0 Generic license, image cropped and resized). Photo by Udo S. Title: Monument Valley - Arizona / USA. The Southwest Region climate in the United States is often associated with extremes. Today, most of the Southwest experiences about 17 fewer freezing days than it did over the last century. Photo by Richard Stephen Haynes (Wikimedia Commons, Creative Commons Attribution-ShareAlike 4.0 International license, image resized). Photo by Jeffrey Beall (Wikimedia Commons,Creative Commons Attribution 4.0 International license, image resized). Facebook Tweet 2. Reconstruction created using basemap from thePALEOMAP PaleoAtlas for GPlatesand the PaleoData Plotter Program, PALEOMAP Project by C. R. Scotese (2016); map annotations by Jonathan R. Hendricks and Elizabeth J. Hermsen for PRI's[emailprotected]project (CC BY-NC-SA 4.0license). (2015) . Summer temperatures in this region rarely rise above 60 F during the day, while winter temperatures hover around 30 F due to the temperate . The final ingredient is wind. Photo by Kenneth Carpenter (Wikimedia Commons,Creative Commons Attribution-ShareAlike 4.0 International license, image cropped and resized). Four of western North America's major watersheds lie within its boundaries: the Colorado River basin, the Rio Grande basin, the Sacramento-San Joaquin watershed, and most of the Great Basin. This project was made possible in part by the Institute of Museum and Library Services (ARPML-250637-OMLS-22).The views, findings, conclusions or recommendations expressed in this website do not necessarily represent those of the Institute of Museum and Library Services. While thats often the situation for the Indian monsoon, the monsoon in North America behaves a bit differently. The monsoon's intensity waned by the early Jurassic, and the rivers and floodplains were replaced by even larger deserts. Drier conditions occurred through the 1920s/1930s, again in the 1950s, and since 1990, when the Southwest has seen some of the most persistent droughts on record (see Figure 3). The continued growth of Pangaea created an intense monsoonal climate, similar to that of Asia today, that affected large parts of the continent. Lake Mead, the lake created by the Hoover Dam, at two points in time about 21 years apart. Used under a Creative Commons license. For example, parts of the Colorado Rockies experience cool annual temperatures and over 8 meters (25 feet) of snowfall every year, while the dry deserts in southwestern Arizona receive only about 8 centimeters (3 inches) of precipitation a year and can experience as much as a 15C (60F) degree temperature difference between night and day. The rainy season would have been critical for Native Americans for thousands of years, and, for some Native American tribes, continues to be so. Accessed March2021. www.ncdc.noaa.gov/cag. The Southwest relies on the slow melt of mountain snowpack throughout the spring and summer, when water demands are highest. 94, 95, 96 Each assessment has consistently identified drought, water shortages, and loss of ecosystem integrity as major challenges that the Southwest confronts under climate change. Submitted by rebecca.lindsey on Thu, 09/30/2021 - 10:13. A .gov website belongs to an official government organization in the United States. The climate of the eastern plains is fairly uniform, with hot, windy summers and thunderstorms. Snowfall will be below normal in most areas that normally receive snow, with the snowiest periods in early to mid-January and early February. 4. Cycads are a group of seed plants that look superficially similar to palms, but are not closely related to them and do not produce flowers. Credits: Most of the text on this page comes from "Climate of the Southwestern US" by Ingrid H. H. Zabel, Judith T. Parrish, and Andrielle N. Swaby, chapter 8 in The Teacher-Friendly Guide to the Earth Science of the Southwestern US, edited by Andrielle N. Swaby, Mark D. Lucas, and Robert M. Ross (published in 2016 by the Paleontological Research Institution; currently out of print). The population of any industrialized and particularly wealthy country produces pollution; the majority of these emissions come from the use of petroleum. The North Rim is 8000 feet (2438meters) to 9000 feet (2743 meters) above sea level. I listened to the Southwest Climate Podcast from CLIMAS, the Climate Assessment for the Southwest, to learn more about what affects the monsoon and its rainfall, and how Monsoon 2021 is shaping up, and reached out to the podcast co-hosts, Zack Guido and Mike Crimmins, for help with this post. In Utah, areas below 1200 meters (4000 feet) receive less than 25 centimeters (10 inches) per year, while higher elevations in the Wasatch Mountains receive more than 100 centimeters (40 inches). Data source: National Drought Mitigation Center, 20213Web update: April2021. By the start of the Late Cretaceous, this inland sea, called the Western Interior Seaway, divided North America in two; the water was rich with mosasaurs, giant clams, and other marine life. The Southwest is typically dry, hot, and humid. Glaciers in the Colorado Rockies are sustained largely by avalanches and wind-blown snow. Eventually, a sheet of sea ice formed over the Arctic, and ice sheets spread over northern Asia, Europe, and North America, signaling the start of the most recent ice age. Summer heat waves will become hotter and longer, while winter cold snaps will occur less often. Cattle ranches throughout the southwestern states rely on rain-fed grazing forage, making them extremely susceptible to climate change and drought. And yet another element of the monsoon system that needs more study to resolve. Please click here to see any active alerts. Left:A petrified stump. A blog about monitoring and forecasting El Nio, La Nia, and their impacts. Most models predict a decrease in winter and spring precipitation by the middle of the century, and more frequent precipitation extremes during the last half of the century. By the end of the Permian, the southern ice sheets had disappeared. This movement of air in different directions is also the reason for the high incidence of powerful tornados that occur along "Tornado Alley" in the Great Plains, which affect eastern New Mexico and especially eastern Colorado. . In the late Ordovician (about 460 to 430 million years ago), the Earth fell into another brief but intense ice age. Global temperatures fell further in the late Miocene thanks to the formation of the Himalayas. Stages in the formation of a thunderstorm. Climate at a glance. Right: As the vertical column of air turns over, with warm air at the top and cool air at the bottom, the storm begins to dissipate. In southern New Mexico, Pleistocene fossil mammals are found that now live at higher elevations in the mountains of northern New Mexico, indicating cooler temperatures and more available moisture in the area during the late Pleistocene. Center:As warm air rises, cool air sinks. The onset of stream flows from melting snow in Colorado has shifted two weeks earlier due to warming spring temperatures. Summer- The summer in the Southwest region is hot and desert-like. Cambrian trilobites from the Bright Angel Shale (Tonto Group), Grand Canyon National Park, Arizona. In New Mexico, for example, the average difference between the daily high and low temperatures ranges from 14 to 19C (25 to 35F). Other elements involved in the ignition and growth of fires and the risks they pose to people living in the Southwest include (but are not limited to) forest management practices, development patterns, and human behavior (intentionally or unintentionally starting fires). :https://earthathome.org/de/what-is-climate/, Digital Encyclopedia of Earth Science: Evidence for and causes of recent climate change:https://earthathome.org/de/recent-climate-change/, Digital Encyclopedia of Earth Science: Climate change mitigation: https://earthathome.org/de/climate-change-mitigation/, Digital Encyclopedia of Earth Science: Climate change adaptation: https://earthathome.org/de/climate-change-adaptation/, [emailprotected]: Quick guides & FAQ: Climate and Energy:https://earthathome.org/quick-faqs/#climate, [emailprotected]: Here on Earth: Introduction to Climate: https://earthathome.org/hoe/climate/. Volcanic activity was strong. contiguous U.S. (CONUS) into the Northern Plains. The main features that influence the areas climate are latitude, regional topography, and a low atmospheric moisture content that leads to quick evaporation. By early to mid-September, wind patterns have generally reverted back to the westerly pattern, bringing an end to the monsoon. Pangaea began to break up during the Jurassic, rifting apart into continents that would drift toward their modern-day positions. Paleontological Research Institution Special Publication 38, Ithaca, NY, 200 pp. This page uses Google Analytics. The lack of moisture in the air allows heat trapped in the earth during daylight hours to rapidly radiate away, leading to cool evenings. Left:Jaw with teeth. Photo by James St. John (flickr, Creative Commons Attribution 2.0 Generic license). Low annual precipitation, clear skies, and year-round warm climate over much of the Southwest are due in large part to a quasi-permanent subtropical high-pressure ridge over the region. Fossil plants, Late Cretaceous Fruitland Formation, San Juan Basin, New Mexico. Rugose corals or horn corals (Turbophyllum) from the Mississippian Great Blue Limestone, Cache Canyon, northern Utah, near the border between the Basin and Range and Rocky Mountain physiographic provinces. Although there has so far been little regional change in the Southwests annual precipitation, the areas average precipitation is expected to decrease in the south and remain stable or increase in the north. The oceans between Gondwana and North America began to close. (1) The North American Monsoon, published in the Bulletin of the American Meteorological Society by David Adams and Andrew Comrie, provides a comprehensive overview of the North American Monsoon and related research through the late 20th century. The North American Monsoon is a seasonal change in the atmospheric circulation that occurs as the summer sun heats the continental land mass. Since then carbon dioxide emissions have been on a downward trend. Also, the occasional eastern Pacific tropical storm can increase monsoon moisture and rainfall. The first letter of each zone in the key indicates its major classification. In a broad sense, the Southwests climate is mostly dry and hot, with much of the region characterized as arid. Alaska weather and daylight varies wildly by region and season, from short-sleeves in summer to down jackets in winter; from 7 rainy days in May in Southcentral to 17 rainy days in the Inside Passage. Map of the Gulf of Mexico region before the closure of the Isthmus of Panama. Summer temperatures on the South Rim, at 7000 feet (2134 meters), are especially pleasant from 50 to about 85 F (10s to 20s C). P. Natl. Utahs distance from both the Pacific Ocean and the Gulf of Mexico prevents heavy precipitation, and much of the state is typically sunny year-round, with light to moderate winds. Despite the areas arid climate, the dunes were surprisingly full of life, particularly in southeastern Utah. It smoldered beneath the ground as a dormant holdover, sleeper, or zombie fire until April, when it flared up and grew into a wildfire, an almost unprecedented occurrence in the Southwest. The Southwest's overall average high temperature of 19.2C (66.6F) and average low of 2.8C (37.0F) are indicative of a varied climate, one much less uniform than that found in many other parts of the United States. A deer mouse (Peromyscus maniculatus) in Portal, Arizona, 2004. When you add in the sparse rain-gauge observations available in the U.S. Southwest and Mexico, it becomes even more difficult to make confident statements about the effects of the monsoon and how it can be predicted. SW Precipitation Precipitation in the Southwest has two distinct seasons. Maps modified from maps by Wade Greenberg-Brand, originally published inThe Teacher-Friendly Guide to the Earth Science of the SouthwesternUS, after figure 3 in L. Grande (2013) The Lost World of Fossil Lake. An increased frost-free season length also leads to increased water demands for agriculture and heat stress on plants. These changes to rain and snow-pack are already stressing water sources and affecting agriculture. Reconstruction created using basemap from thePALEOMAP PaleoAtlas for GPlatesand the PaleoData Plotter Program, PALEOMAP Project by C. R. Scotese (2016); map annotations by Jonathan R. Hendricks & Elizabeth J. Hermsen for PRI's[emailprotected]project (CC BY-NC-SA 4.0license). The Palmer Index is calculated from precipitation and temperature measurements at weather stations, and has been used widely for many years. Of the southwestern states, Arizona emits the most greenhouse gases, releasing 92.5 million metric tons of energy-related carbon dioxide (CO2) in 2019. Climate at a glance. These oases were fed by groundwater that originated in the higher country of what is now western Colorado. Image above: Sun and storm in Weld County, in the Great Plains region of Colorado, 2015. At the very end of the Cretaceous, the Gulf Coast experienced an enormous disruption when a large asteroid or bolide collided with Earth in what is now the northern Yucatn Peninsula in Mexico. In general, it is expected that high alpine glaciers in the Colorado Rockies will disappear as the climate continues to warm. Taken on August 15, 2016. Pacific storms lose most of their moisture as they pass over the Rocky Mountains, so much of the Southwest's winter precipitation falls as snow within the areas mountainous regions. Smog (haze caused by air pollution) over Salt Lake City, Utah, 2016. Average annual preciptiation for the southwestern U.S. (41-60 degrees.) Thus, even a small increase in temperature (which drives evaporation) or a decrease in precipitation in this already arid region can seriously threaten natural systems and society. The warmest temperatures in the Southwest are found in Arizona and New Mexico, while the coolest are found in Utah and Colorado. This map shows how the average air temperature from 2000 to 2020has differed from the long-term average (18952020). During much of the year, the prevailing wind over northwestern Mexico, Arizona, and New Mexico is westerly (blowing from the west) and dry. Extreme high temperatures. Left:Warm air rises. Natural variability, changes in irrigation practices, and other diversions of water for human use can influence certain drought-related measurements. Is the tropical storm season done for this part of the country? Agriculture accounts for more than half of the Southwests water use, so any major reduction in the availability of water resources will create a serious strain on ecosystems and populations. In southern New Mexico and Arizona, shallow marine deposits, laid down when the ice in Gondwana retreated and sea level rose, alternate with layers of dust blown in when the ice in Gondwana advanced and sea level fell. For example, the difference in annual mean temperature between Pikes Peak (4302 meters or 14,114 feet) and Las Animas (1188 meters or 3898 feet), only 145 kilometers (90 miles) to the southeast, is equivalent to that between Iceland and southern Florida! The average amount of precipitation for the United States is 85.6 centimeters (33.7 inches). Photos by Lauren Dauphin, NASA Earth Observatory (used following NASA's image use policy). But El Nio leads to more tropical storms than average, youre saying, because youre not new here. Go to the full list of resources about the climate of the southwestern U.S. Go to the full list of general resources about climate. Although there has been a fair amount of research into the monsoon, there are still far more questions than answers about how it works, and if the seasonal amount of rain, potential start date, or other characteristics can be predicted. Where the land was exposed, deposits of dust (loess) accumulated and were blown across much of the Southwest. Photo source:National Park Service (public domain). Check out Toms recent post on the drought in Arizona to understand more about how drought works in this region. Before the Isthmus closed, the Atlantic and Pacific oceans were connected. Modified fromFigure 11 in Kirby et al. The rainfall generally has a strong diurnal cycle, meaning a daily pattern of mostly dry mornings, storms developing through the day, and most rainfall occurring in the afternoon and evening. Its largely too soon to tell. Droughts also contribute to increased pest outbreaks and wildfires, both of which damage local economies, and they reduce the amount of water available for generating electricityfor example, at the Hoover Dam.1. Large glaciers were found at higher elevations, and temperatures were cool. Agua Caliente solar farm, Maricopa County, Arizona. Thanks thats a big pool of warm water larger than the gulf of California and warmer than the greater Pacific Ocean. The desert experiences large temperature extremes, especially between day and night; daily temperature may change as much as 15C (60F) during the driest parts of the year. Note that the southwestern region of the U.S. is covered by a shallow sea. We are largely unaware of this precipitation because of the Southern California Chamber of Commerce and a lack of rain gauges. See you then! Flows in late summer are correspondingly reduced, leading to extra pressure on the states water supplies. Elevation does, however, play a key role in precipitation received throughout the Southwest. Photos of YPM IP 529539 by Jessica Utrup, 2015 (Yale Peabody Museum of Natural History/YPM,CC0 1.0 Universal/Public Domain Dedication, viaGBIF.org). At any rate I'd just like to point out a potential clue to your springtime predictability barrier problem. however, the monsoons provide life-giving moisture in a region that is always dry. Photo of USNM 166396 from the Cretaceous Atlas of Ancient Life(Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International license, image cropped). The warming conditions alone can be impactful, drying out soils quicker during breaks in monsoon rainfall, for example (2). Las Cruces, New Mexico, 2006. Monsoon region averaged over all land gridpoints, 20N37N, 102W115W. Zack and Mike mention that last year was an extremely dry monsoon, and this year is extremely wet. Climate change can intensify multiple stresses that push a species past a survival threshold. Today nearly all the glaciers in the Southwest are gone, and the climate is in an arid state. Submitted by rebecca.lindsey on Thu, 09/30/2021 - 10:14. Maps and data. (2011)PLoS ONE3(7): e2791(Creative Commons Attribution license, image reorganized and resized). Dark gray is land, white and light gray are submerged areas. Photoandreconstructionby National Park Service/NPS (public domain). Southwest Asia is a region of diverse climates and is generally divided into three main climate types: arid, semiarid, and temperate.