The Southwest has a very unique culture, climate, and geography. Photo by Eltiempo10 (Wikimedia Commons, Creative Commons Attribution-ShareAlike 4.0 International license, image resized). Thanks thats a big pool of warm water larger than the gulf of California and warmer than the greater Pacific Ocean. Shallow seaways spread over many of the continents, including South America, Africa, Eurasia, and North America. 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. Unless otherwise indicated, text and images on this website have Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International licenses. MacDonald, G.M. Did La Nia drench the Southwest United States in early winter 2022/23? Fall- The fall in the Southwest region is warm. Approximately 3.5 million years ago, glacial ice began to form over the Arctic Ocean and on the northern parts of North America and Eurasia. Today nearly all the glaciers in the Southwest are gone, and the climate is in an arid state. The Palmer Index is calculated from precipitation and temperature measurements at weather stations, and has been used widely for many years. 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. Also extreme dryness which means days & weeks on end without rain. A large, low-latitude desert formed along Pangaea's western margin, generating extensive dune deposits. 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. NASA Earth Observatory image by Lauren Dauphin (NASA Earth Observatory,used following NASA's image use policy). Precipitation, while sparse, peaks in the summer during the monsoonal storms, and again in the winter from storms originating in the Pacific Ocean. Left:Jaw with teeth. Light precipitation travels eastward over the Sierra Nevada and Cascade mountains after dropping heavy snowfall in areas of high elevation. However, the Southwest is located between the mid-latitude and subtropical atmospheric circulation regimes, and this positioning relative to shifts in these . How would that result in less total JulyAugust rain? Good question! Higher atmospheric moisture content has also been correlated with an increased incidence of tornados and winter storms. The warmer the air near the surface is relative to the air above it, the more potential energy it has to move up. Right:Dolichometoppus productus. (Going forward, to avoid having to say northwestern Mexico, Arizona, and New Mexico over and over, Ill refer to this area as the monsoon region.). Forecasts had all of this widespread flash flooding. Temperatures in the southwest region average greater than states up North, because there isn't as much water vapor in upper level winds to screen direct sunlight. PRI is a registered 501(c)(3) nonprofit organization. In the podcast episode 2021a generational monsoon? Zack listed some of the factors that influence how much moisture is available to the monsoon, including the position of the high-pressure area, wind patterns, and transient weather features. Photo by Santa Fe National Forest (National Interagency Fire Center on flickr, public domain). Right:Reconstruction of living animals. The Southwest has a hot desert climate, at lower elevations. The North American Monsoon is a seasonal change in the atmospheric circulation that occurs as the summer sun heats the continental land mass. Regional overview Southwest. The number of days with temperatures above 35C (95F) and nights above 24C (75F) has been steadily increasing since 1970, and the warming is projected to continue. Loess is often, though not exclusively, associated with dry areas around glaciers. An increased frost-free season length also leads to increased water demands for agriculture and heat stress on plants. Wind moves the air, promoting mixing. The cycling layers in thesandstone represent changes in the direction of prevailing winds as large sand dunes migratedacross the desert. however, the monsoons provide life-giving moisture in a region that is always dry. Accessed March 2021. https://droughtmonitor.unl.edu/DmData/DataTables.aspx. Secure .gov websites use HTTPS Sun and storm in Weld County, in the Great Plains region of Colorado, 2015. Natural variability, changes in irrigation practices, and other diversions of water for human use can influence certain drought-related measurements. Water is already scarce in the Southwest, so every drop is a precious resource. Hailstones from a storm in Limon, Colorado, 2010. Lake Powell, the lake created by Glen Canyon Dam, at two points in time about four years apart. During the Paleocene to Eocene, the Southwests climate was warm and wet, and large mammals roamed the forested landscape. Roadcut exposing lake sediments of the Eocene Green River Formation, Duchesne County, Utah. Dry air is shown in orange. Convection occurs when buoyant warm air rises (moves up) while denser cool air sinks (moves down). A lock (LockA locked padlock) or https:// means youve safely connected to the .gov website. Modified fromFigure 11 in Kirby et al. As average temperatures rise and the Southwest becomes drier with a longer annual fire season (season conducive to the ignition and spread of wildfires), the number and intensity of wildfires is expected to increase. The monsoon's intensity waned by the early Jurassic, and the rivers and floodplains were replaced by even larger deserts. The population of any industrialized and particularly wealthy country produces pollution; the majority of these emissions come from the use of petroleum. 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. Fossil plants, Late Cretaceous Fruitland Formation, San Juan Basin, New Mexico. By comparison, the average high and low temperatures for the entire United States are 17C (63F) and 5C (41F), respectively. 2021. Photo by Center for Land Use Interpretation(Creative Commons Attribution-Noncommercial-ShareAlike 3.0 license, image resized). Where the land was exposed, deposits of dust (loess) accumulated and were blown across much of the Southwest. Likewise, its not yet clear how the monsoon is changing in the warming climate, or how it will in the future. Its remnant exists today as the Great Salt Lake. The Drought Monitor is a more recent and more detailed index based on several other indices (including Palmer), along with additional factors such as snow water content, groundwater levels, reservoir storage, pasture/range conditions, and other impacts. 2. 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. Map made by Elizabeth J. Hermsen usingSimplemapprand modified in Photoshop. When you take an already highly variable phenomenon like rainfall, add in uncertain regional climate change impacts, and factor in the sparse data record, it gets difficult to make a strong case about exactly how the monsoon rainfall is changing. :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/. 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). Photo by Lane Pearman (flickr, Creative Commons Attribution 2.0 Generic license, image cropped and resized). Photograph by Bill Morrow (Flickr;Creative Commons Attribution 2.0 Generic license). Since 1980, tree mortality in forests and woodlands across the Southwest has been higher and more extensive than at any time during the previous 90 years. Maps showing the progressive closure of the Isthmus of Panama at 20 million years ago (A) and 15 million years ago (B). Andrews Glacier in Rocky Mountain National Park, Colorado, at two points in time. For example San Diego county has a population of azalea otherwise not seen for hundreds of miles to the north. contiguous U.S. (CONUS) into the Northern Plains. Scale bar = 1 centimeter (about 0.4 inches). The cities of Aspen and Lafayette, Colorado, as well as the state of New Mexico, were early adopters of the 2030 Challenge, an effort to reduce fossil fuel use in buildings so that both new and renovated buildings would qualify as carbon neutral by the year 2030. 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). However, although climate change is predicted to enhance the intensity of severe weather, there is currently no way to calculate what effect climate change will have on the frequency of specific storm eventsfor example, we might see more powerful tornados, but we do not know if we will see more of them. The summer precipitation total for the CONUS was 9.48 inches, 1.16 inch above average, ranking eighth wettest in the historical record. Map of the modern Yucatn Peninsula region showing the location of the Chicxulub impact crater. Figure by Climate.gov. There were spots that received large amounts of rain, but overall Nora was a bust. Fossil mammals adapted to colder temperatures are found in the Pleistocene of Colorado. 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. Modified from a map by Adam Peterson (Wikimedia Commons,Creative Commons Attribution-ShareAlike 4.0 International license). For temperature, the 2020 monsoon was the hottest on record for the Southwest with an average temperature of 77.1 F, significantly beating the previous record of 76.8 F in 2011 (average is 74.3 F). Time-series graph of energy-related carbon dioxide emissions from southwestern states, showing rising emissions from 1970 to around 2008, followed by a decreasing trend from 2008 to 2019. This planting zone combines saline water and alkaline soil with intense sunlight, high temperatures and varying elevations. Figures 2 and 3 show two ways of measuring drought in the Southwest: the Drought Monitor and the Palmer Drought Severity Index. Precipitation forms. Extreme high temperatures. 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. The event devastated the Southwest, shifting a densely forested landscape to one primarily covered with fast-growing herbs and ferns. During this time, the only exposed areas were islands in western Colorado and parts of New Mexico. As the Triassic period began, the Southwest moved north from the equator. Despite the areas arid climate, the dunes were surprisingly full of life, particularly in southeastern Utah. Large glaciers were found at higher elevations, and temperatures were cool. The impact vaporized both water and rock, blocking out sunlight for weeks to years, which led to a collapse of photosynthesis and food webs on land and in the oceans. Lower latitudes receive more heat from the sun over the course of a year; for each degree increase in latitude, there is approximately a 1C (2F) decrease in temperature. Extensive Permian deposits throughout the Southwest are home to a host of fossils, including terrestrial amphibians, reptiles, and synapsids. Precipitation also varies widely. The Southwest, already the driest region in the United States, has become even drier since the mid-20th century, particularly on the hottest days . Carbon dioxide emissions in Arizona rose through the last three decades of the 20th century and reached a peak in 2008. The inner canyon temperatures are extreme and hot, with a lower elevation of about 2400 feet (732 meters). The location of the Southwest and the topographical extremes across this area strongly influence its weather. The state's highest temperatures occur in the northeastern plains, where they can exceed 46C (115F). The state's mountainous areas, however, have climate characteristics that more closely follow those found in the Colorado Rockies. By early to mid-September, wind patterns have generally reverted back to the westerly pattern, bringing an end to the monsoon. As the continents moved closer to their modern positions, the Southwest experienced a hot and humid tropical climate. Left:Warm air rises. | View Google Privacy Policy. Photo by Daniel Mayer (Wikimedia Commons, Creative Commons Attribution-ShareAlike 3.0 Unported license, image resized). More on that later Now, lets take a sojourn through some North American Monsoon basics (1). Ideas and explanations found in these posts should be attributed to the ENSO blog team, and not to NOAA (the agency) itself. What is the climate in the Southwest region in summer? Soils associated with these floodplains testify to the extreme seasonality of rainfall during that time. 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! Colorado has a generally cool and continental climate with low humidity. 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. Smog (haze caused by air pollution) over Salt Lake City, Utah, 2016. The supercontinent was split by spreading along the mid-Atlantic ridge, initiating the formation of the Atlantic Ocean. 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 . Average annual temperatures for the southwestern U.S. (2015) . But El Nio leads to more tropical storms than average, youre saying, because youre not new here. It is the largest wildfire that New Mexico has ever witnessed. An official website of the United States government. Famous sheriffs like Wyatt Earp and outlaws like Billy the . Image by The High Fin Sperm Whale, created from images by NOAA National Weather Service training material (Wikimedia Commons, public domain). Southwest Asia is a region of diverse climates and is generally divided into three main climate types: arid, semiarid, and temperate. For the climate on early Earth prior to 541 million years ago, see the Introduction to Climate section. During the winter, moisture travels from the west, as storms from the Pacific Ocean move east. Brown indicates where precipitation has been less than average; green is greater than average. 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. Convective mixing forces the moisture in warm air to condense as it comes into contact with cool air, forming vapor (clouds) and precipitation (for example, rain or hail). After the end-Cretaceous bolide impact, the climate may have cooled briefly, but it soon rebounded to a warmer state. Photo of USNM P 38052 by Frederic Cochard (Smithsonian National Museum of Natural History, public domain). That's at least one part of a very big climate puzzle crossing that barrier that involves both the ocean and atmosphere. By comparison, the average high and low temperatures for the entire United States are 17C (63F) and 5C (41F), respectively. By the late Carboniferous, North America had collided with Gondwana, leading to the formation of Pangaeaa supercontinent composed of nearly all the landmass on Earth. Summer heat waves will become hotter and longer, while winter cold snaps will occur less often. Reconstruction created usingPaleomap(by C. Scotese) forGPlates. Its largely too soon to tell. Tornado Alley is identified. Every part of the Southwest experienced higher average temperatures between 2000 and 2020than the long-term average (18952020). Photo of USNM 166396 from the Cretaceous Atlas of Ancient Life(Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International license, image cropped). Photo credits: 1916 photo from USGS (public domain), 2013 photo by daveynin (flickr,Creative Commons Attribution 2.0 Generic license, image resized). Photo by James St. John (flickr,Creative Commons Attribution 2.0 Generic license, image cropped and resized). Cattle ranches throughout the southwestern states rely on rain-fed grazing forage, making them extremely susceptible to climate change and drought. Kppen climate map of the 48 contiguous states of the continental United States. One recent study explored the relationship between the monsoon and wildfires in the Southwest and northern Mexico, finding that monsoon rains were important for ending wildfires. 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 inset image is a shaded relief image that shows the edge of the crater on the Yucatn Peninsula with sinkholes in the rock surrounding it. Photo by James St. John (flickr, Creative Commons Attribution 2.0 Generic license). The American Southwest, here defined as the area between 95W and 125W and 25N and 40N, 9 covers over four million square kilometers. 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. By the end of the Cretaceous, uplift to the west was great enough that the resulting hills shed large amounts of sand and gravel in an easterly direction, pushing the shoreline eastward until sediment (combined with a worldwide drop in sea level) filled the area formerly occupied by the Western Interior Seaway. The causes of specific weather events such as tornados and severe thunderstorms are incredibly complex, although climate change has enhanced some correlated factors, such as increased wind speed and an unstable atmosphere. Rainfall, as anyone who has read the ENSO Blog before will know, is an extremely complicated thing to predict! This chart shows annual values of the Palmer Drought Severity Index, averaged over six states in the Southwest (Arizona, California, Colorado, Nevada, New Mexico, and Utah). Average temperatures found in the Southwest tend to decrease northward, which is largely the influence of latitude and elevation. Map modified from amap by Chiche Ojeda (Wikimedia Commons,Creative Commons Attribution-ShareAlike 4.0 International license, image cropped and modified). Winter- The winter in the Southwest region is mild, and hot. All of these plants, animals, and people need water to survive. We can see some hints of this relationship in my scatter-plot here. Share sensitive information only on official, secure websites. Source:FEMA National Risk Index. Ive summarized their conclusions above, and include the quotes here, but I suggest you head over to the full science report if youre in the mood for some specifics. What is the weather like in the Southwest region in summer? He pointed out that ENSO does influence Pacific tropical storms, which can supply moisture to the monsoon. Also, the occasional eastern Pacific tropical storm can increase monsoon moisture and rainfall. The impacts of the monsoon go beyond just rainfall amounts. Data source: National Drought Mitigation Center, 20213Web update: April2021. Thanks for visiting the North American Monsoon region with me! Brown indicates areas where experts forecast drought will persist or worsen. In fact, this monsoon may turn out to be the wettest on record for some places! A= Tropical (equatorial),B= Arid,C= Temperate (warm temperate),D= Continental (cold),E= polar. Data: U.S. Energy Information Administration. 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. The North Rim is 8000 feet (2438meters) to 9000 feet (2743 meters) above sea level. | View Google Privacy Policy. Sprawling development of Phoenix, Arizona, a city in the Sonoran Desert, 2009. The main features that influence the areas climate are latitude, regional topography, and a low atmospheric moisture content that leads to quick evaporation. Fig. The final ingredient is wind. Since then carbon dioxide emissions have been on a downward trend. The full time series for precipitation and temperature values is shown in Figure 2. New Mexico, Utah, and Colorado have also reduced their carbon dioxide emissions between 2008 and 2019. There is some variability in the onset and demise of the monsoon. NOAA (National Oceanic and Atmospheric Administration). Typically, a storm blows itself out once the warm air has moved up and the cool air has moved down. The Cretaceous-Paleogene boundary at Trinidad Lake State Park, Las Animas County, Colorado. Summer temperatures on the South Rim, at 7000 feet (2134 meters), are especially pleasant from 50 to about 85 F (10s to 20s C).