Data from Global Precipitation Climatology Centre (GPCC) and ERSSTv5. Photo by Daniel Mayer (Wikimedia Commons, Creative Commons Attribution-ShareAlike 3.0 Unported license, image resized). Shallow seas invaded the continent, ultimately covering the whole area until the late Carboniferous. Across New Mexico, Arizona, and Utah, summer rains originate from moisture brought into the area from the Gulf of Mexico. More on that later Now, lets take a sojourn through some North American Monsoon basics (1). Sci. contiguous U.S. (CONUS) into the Northern Plains. Share sensitive information only on official, secure websites. Convective mixing stops because the vertical column of air has turned over so that the cool air is at the bottom and the warm air is at the top. 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. P. Natl. 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. There is some variability in the onset and demise of the monsoon. This fire, which started as two separate fires that merged, began in April 2022 and has since burned more than 138,000 hectares (340,000 acres) of land and over 300 homes. This chart shows the percentage of land area in six southwestern states (Arizona, California, Colorado, Nevada, New Mexico, and Utah) classified under drought conditions from 2000 through 2020. 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. Topics covered on this page: Present climate of the southwestern U.S.; Present temperature; Present precipitation; Severe weather; Regional climate variation; Past climate of the southwestern U.S.; Paleozoic; Mesozoic; Cenozoic; Future climate of the southwestern U.S.; Resources. The North American Monsoon is a seasonal change in the atmospheric circulation that occurs as the summer sun heats the continental land mass. Photo by James St. John (flickr,Creative Commons Attribution 2.0 Generic license, image cropped and resized). The pyrocumulonimbus cloud shown at the arrow was created by heat from the fire. 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 summer precipitation total for the CONUS was 9.48 inches, 1.16 inch above average, ranking eighth wettest in the historical record. Higher elevations (such as those found in the Rockies and on the Colorado Plateau) are also cooler, with approximately a 1.5C (3F) decrease in mean annual temperature for each 300-meter (1000-foot) increase in elevation. The formation of precipitation also causes electrical charging of particles in the atmosphere, which in turn produces lightning. 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. Summer temperatures on the South Rim, at 7000 feet (2134 meters), are especially pleasant from 50 to about 85 F (10s to 20s C). 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. Large lakes covered parts of northern Utah and Colorado. Figure by Ingrid Zabel for PRI's [emailprotected] project (CC BY-NC-SA 4.0 license). Climate changepast, present & future: a very short guide. Copyright 2021 Paleontological Research Institution. Data: U.S. Energy Information Administration. Photo by Dr. David Goodrich, NOAA (NOAA Photo Library ID wea04192, NOAA's National Weather Service, via flickr, Creative Commons Attribution 2.0 Generic license, image cropped and resized). Photo by James St. John (flickr, Creative Commons Attribution 2.0 Generic license, image resized). 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. Left imageandright imageby NickLongrich (Wikimedia Commons,Creative Commons Attribution-ShareAlike 4.0 International license, images cropped and resized). 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. 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. Precipitation also varies widely. Water, climate change, and sustainability in the Southwest. Forecasts had all of this widespread flash flooding. Accessed March 2021. https://droughtmonitor.unl.edu/DmData/DataTables.aspx. NOAA (National Oceanic and Atmospheric Administration). Wildfire risk map for the United States. 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). For the climate on early Earth prior to 541 million years ago, see the Introduction to Climate section. Because high mountains to the west and north act as a barrier to cold Arctic air masses, most areas of Utah rarely experience temperatures below freezing or prolonged periods of extreme cold. These oases were fed by groundwater that originated in the higher country of what is now western Colorado. (41-60 degrees.) Thick salt deposits accumulated in the northwestern Four Corners area as the seas evaporated. Download related technical information PDF, https://droughtmonitor.unl.edu/DmData/DataTables.aspx, A Closer Look: Temperature and Drought in the Southwest. 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). The daily range between maximum and minimum temperatures sometimes runs as much as 50 to 60 degrees F during the drier periods of the year. Did La Nia drench the Southwest United States in early winter 2022/23? 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). The average precipitation for the United States is 85.6 centimeters (33.7 inches). Thanks to the region's high temperatures and low precipitation levels from summer 2020 through summer 2021, the current drought has exceeded the severity of a late-1500s megadrought that previously had been identified by the same authors as the driest in 1,200 years. Kppen climate map of the 48 contiguous states of the continental United States. Wind moves the air, promoting mixing. 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). Temperature and drought data come from a network of thousands of weather stations overseen by the National Weather Service. 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. 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. 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. The Santa Catalina Mountains near Tucson, Arizona are surrounded desert in which saguaro cacti grow. The climate remained warm, despite large southern ice sheets, but it had grown much drier. Is the tropical storm season done for this part of the country? Glaciers covered most of the world's southern landmasses, which were located over the South Pole. The Central American Isthmus, which today makes up most of Panama and Costa Rica, rose out of the ocean at approximately this time, formed by undersea volcanoes. Today, most of the Southwest experiences about 17 fewer freezing days than it did over the last century. The elevation of Bear Lake is about 2880 meters (9450 feet). Inset image from the NASA Jet Propulsion Laboratory (PIA03397). As the summer heat builds over North America, a region of high pressure forms over the U.S. Southwest, and the wind becomes more southerly, bringing moisture from the Pacific Ocean and the Gulf of California. SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS. Fossil ammonoid (Nigericeras scotti) from the Late Cretaceous Greenhorn Limestone, Baca County, Colorado. In 2020, Colorado ranked 7th in the nation for solar and wind power production, and Arizona and New Mexico ranked 12th and 13th, respectively. Pangaea began to break up during the Jurassic, rifting apart into continents that would drift toward their modern-day positions. (2019)Biology Letters15: 20190114(Creative Commons Attribution 4.0 International license, images cropped, reconfigured, resized, and relabeled). Dry air is shown in orange. The Southwest is also definable, to an extent, by environmental conditions - primarily aridity. Glaciation in the Southern Hemisphere occurred during the late Devonian, while the supercontinent Gondwana was located over the South Pole, and intensified during the early Carboniferous. Bear Lake and Glacier Gorge, Rocky Mountain National Park, Colorado, 2011. February 2023 ENSO update: the ENSO Blog investigates, part 3, How the pattern of trends across the tropical Pacific Ocean is critical for understanding the future climate, January 2023 La Nia update, and the ENSO Blog investigates, part 2, Albuquerque, NM National Weather Service office, ENSO does influence Pacific tropical storms, Tucson recorded its wettest month ever this July, Monsoon causes deadly flash flood in Arizona, Images of CO2 emissions and transport from the Vulcan project, TreeFlow: Streamflow Reconstructions from Tree Rings. Also extreme dryness which means days & weeks on end without rain. Every part of the Southwest experienced higher average temperatures between 2000 and 2020than the long-term average (18952020). Average annual preciptiation for the southwestern U.S. Climate.gov image of original from Albuquerque, NM National Weather Service office. Skeleton of a juvenileCamarosaurs lentus, a type of sauropod, from the Carnegie Quarry, Jurassic Morrison Formation, Dinosaur National Monument, Utah and Colorado. 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. One especially alarming detail about the Calf Canyon fire is that it was originally set in January 2022. Lake Powell, the lake created by Glen Canyon Dam, at two points in time about four years apart. Winter will be warmer than normal, with above-normal precipitation. We are largely unaware of this precipitation because of the Southern California Chamber of Commerce and a lack of rain gauges. Unless otherwise indicated, text and images on this website have Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International licenses. Arizona's highest elevations receive an average of 65 to 76 centimeters (25 to 30 inches), with lower areas in the states southwestern portion averaging less than 8 centimeters (3 inches). Summer temperatures in this region rarely rise above 60 F during the day, while winter temperatures hover around 30 F due to the temperate . As of June 2022, it was more than 90% contained. During winter months, daytime temperatures may average 70 degrees F, with night temperatures often falling to freezing of slightly below in the lower desert valleys." In the middle Cretaceous, oceans covered most of the Southwest, with the exception of parts of Arizona and New Mexico. 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. While this will help with the ongoing drought in the southwest, in many regions the precipitation deficit has been building for a long time. Wetter-than-average monsoons (green dots) are slightly more common during La Nia years, while drier-than-average monsoons (brown dots) are slightly more common during El Nio years. :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/. Facebook Tweet Precipitation has become more variable from year to year, and heavy downpours across the U.S. have increased in the last 20 years. This chapter builds on assessments of climate change in the Southwest region from the three previous U.S. National Climate Assessments. Climate change is affecting the Southwest's water resources, terrestrial ecosystems, coastal and marine environments, agriculture, and energy supply. Photo by Jeffrey Beall (Wikimedia Commons,Creative Commons Attribution 4.0 International license, image resized). Deer mice are the most important rodent carriers of hantavirus in the Southwest. Figure by climate.gov; data from CPC Unified data. Accessed March2021. www.ncdc.noaa.gov/cag. Photo by Stefan Klein (Wikimedia Commons, Creative Commons Attribution-ShareAlike 4.0 International license, image cropped and resized). Arizona's climate is influenced by three main topographical areas: the high Colorado Plateau (about 15202130 meters or 50007000 feet in elevation), the rugged mountains to the west (27403660 meters or 900012000 feet high), and the low southwestern mountains with desert valleys (as low as 30 meters or 100 feet above sea level). 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. As a result of displacement due to continental rifting and seafloor spreading, sea level throughout the Cretaceous was much higher than it is today. 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. The current drought outlooks expect that the drought in Arizona and New Mexico will improve in the short term, but persist. Agua Caliente solar farm, Maricopa County, Arizona. The formation of precipitation also causes electrical charging of particles in the atmosphere, which in turn produces lightning. 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! All rights reserved. Although on the western edge of the North American Monsoon, California plant geography indicates it makes a large contribution to the states southern flora. Drought outlook for the Lower 48 U.S. states in August 2022. 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. At the close of the Mesozoic, global climatealthough warmer than todaywas cooler than at the start of the era. Center:As warm air rises, cool air sinks. The continued growth of Pangaea created an intense monsoonal climate, similar to that of Asia today, that affected large parts of the continent. Famous sheriffs like Wyatt Earp and outlaws like Billy the . :https://earthathome.org/de/talk-about-climate/, Digital Encyclopedia of Earth Science: What is climate? Changes include formatting and revisions to the text and images. This circulation brings thunderstorms and rainfall to the monsoon region, providing much of their annual total precipitation. 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 . The monsoon's intensity waned by the early Jurassic, and the rivers and floodplains were replaced by even larger deserts. Carbon dioxide emissions in Arizona rose through the last three decades of the 20th century and reached a peak in 2008. MacDonald, G.M. The book was adapted for the web by Elizabeth J. Hermsen, Jonathan R. Hendricks, and Ingrid Zabel in 2022. 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. Climate change can intensify multiple stresses that push a species past a survival threshold. Photo by Kenneth Carpenter (Wikimedia Commons,Creative Commons Attribution-ShareAlike 4.0 International license, image cropped and resized). The thunderstorm begins. The main features that influence the areas climate are latitude, regional topography, and a low atmospheric moisture content that leads to quick evaporation. The last glacial advance of the modern ice age peaked some 18,000 years ago. The lack of moisture in the air allows heat trapped in the earth during daylight hours to rapidly radiate away, leading to cool evenings. Resilient Bermudagrass is widely used in the region, but sufficient watering is essential in the desert climate . Regarding changes that have already occurred, the report finds modest evidence that the monsoon rainfall has intensified since the 1970s, and this has been partly attributed to greenhouse gas emissions. 2. Monsoon region averaged over all land gridpoints, 20N37N, 102W115W. A deer mouse (Peromyscus maniculatus) in Portal, Arizona, 2004. Before the Isthmus closed, the Atlantic and Pacific oceans were connected. The world warmed, and would stay warm through the Mesozoic. For example, high winter temperatures between 2000 and 2003 correlated to bark beetle outbreaks that devastated pinyon pine throughout the Southwest, leading to nearly 90% mortality at some sites in Colorado and Arizona. Las Cruces, New Mexico, 2006. The onset of stream flows from melting snow in Colorado has shifted two weeks earlier due to warming spring temperatures. In addition, temperature increases and recent drought have resulted in earlier spring snowmelt and decreased snow cover on the lower slopes of high mountains, bringing about more rapid runoff and increased flooding. Reconstruction created using basemap from the. Photo by Lane Pearman (flickr, Creative Commons Attribution 2.0 Generic license, image cropped and resized). Data source: NOAA, 20214Web update: April2021, Key Points | Background | About the Data | Technical Documentation. 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. 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. As the continents moved closer to their modern positions, the Southwest experienced a hot and humid tropical climate. This page uses Google Analytics. Photo of USNM 166396 from the Cretaceous Atlas of Ancient Life(Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International license, image cropped). Introduction The overall climate of the Southwestits weather patterns over a long period of timetends to be warm and dry. The Southwest is typically dry, hot, and humid. Right:Reconstruction of living animals. The distance between Santa Fe and Las Vegas, New Mexico, is about 65 kilometers (about 40.5 miles). The more than 16 million residents of the Southwest use carbon-rich fossil fuels to provide electricity for lighting, cooling, and appliances, to fuel their transportation and industry, and to make the products they use. For example San Diego county has a population of azalea otherwise not seen for hundreds of miles to the north. Used under a Creative Commons license. Left:Lake Bonneville's maximal extent during the Pleistocene. A .gov website belongs to an official government organization in the United States. Unless otherwise indicated, text and images on this website have Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International licenses. The event devastated the Southwest, shifting a densely forested landscape to one primarily covered with fast-growing herbs and ferns. There is also an important relationship between rainfall and temperature: usually, more rain leads to cooler conditions, and less rain leads to hotter conditions. Ornithopod-type tracks, Powell Fossil Track Block Tracksite, Jurassic Navajo Sandstone, Glen Canyon National Recreation Area, Arizona and Utah. New Mexico, Utah, and Colorado have also reduced their carbon dioxide emissions between 2008 and 2019.