A= Tropical (equatorial),B= Arid,C= Temperate (warm temperate),D= Continental (cold),E= polar. Unless otherwise indicated, text and images on this website have Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International licenses. 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.. Its largely too soon to tell. Moving westward, Colorado's foothills and mountainous areas experience an overall cooler climate and higher levels of precipitation. These changes threaten economic productivity, public health, and the sustainability of Indigenous communities. Here on Earth: Regional Guides to Earth Science, Earth Science of the Southwestern United States, Climate of the Southwestern United States. 2. Photo by Daniel Mayer (Wikimedia Commons, Creative Commons Attribution-ShareAlike 3.0 Unported license, image resized). For extended periods from 2002 to 2005 and from 2012 to2020, nearly the entire region was abnormally dry or even drier (see Figure 2). Data for Figures 1 and 3 were obtained from the National Oceanic and Atmospheric Administrations National Centers for Environmental Information, which maintains a large collection of climate data online at: www.ncdc.noaa.gov/cag. Did La Nia drench the Southwest United States in early winter 2022/23? The formation of precipitation also causes electrical charging of particles in the atmosphere, which in turn produces lightning. An official website of the United States government. Check out Toms recent post on the drought in Arizona to understand more about how drought works in this region. Photo of USNM 166396 from the Cretaceous Atlas of Ancient Life(Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International license, image cropped). Right:Sabalites, a palm leaf. 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. 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. Data from Global Precipitation Climatology Centre (GPCC) and ERSSTv5. Photoandreconstructionby National Park Service/NPS (public domain). At this time, the Southwest was still submerged. ; Precipitation was above-average across portions of the Great Basin and Southwest, from the southern Plains to the Great Lakes and across much of the eastern U.S. Mississippi had its wettest summer on record with Alabama, Michigan, New York and Massachusetts . Climate change is affecting the Southwest's water resources, terrestrial ecosystems, coastal and marine environments, agriculture, and energy supply. Brown indicates areas where experts forecast drought will persist or worsen. The March-April-May (MAM) 2023 temperature outlook favors below-normal. Accessed March2021. www.ncdc.noaa.gov/cag. The highest point in these mountains has a relief of 1572 meters (5157 feet) over the surrounding landscape, and the mountains are tall enough to receive snowfall. This feature provides a closer look at trends in temperature and drought in the southwestern United States. Drought outlook for the Lower 48 U.S. states in August 2022. Bark beetles, which normally die in cold weather, have been able to survive through the winter and reproduce, increasing tree mortality. In winter, rising temperatures have increased the number of frost-free days. Petrified log at Escalante Petrified Forest State Park, Jurassic Morrison Formation, Garfield County, Utah. 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). By 2070, one can expect up to 38 more days of freeze-free weather each year. This figure uses the U.S. Drought Monitor classification system, which is described in the table in the Droughtindicator. Inset image from the NASA Jet Propulsion Laboratory (PIA03397). Map by NOAA(public domain) modified for the[emailprotected]project. Fall- The fall in the Southwest region is warm. Figure by climate.gov. Winter is the driest season in New Mexico, because precipitation from eastward-traveling Pacific storms is left behind in the western mountains of Arizona and Utah. Climate.gov image of original from Albuquerque, NM National Weather Service office. As in Arizona, the desert experiences a large range of temperature on a daily basis. Photo by Bob Wick, Bureau of Land Management (flickr, public domain). 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. Wildfire risk map for the United States. We can see some hints of this relationship in my scatter-plot here. 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). As a result of displacement due to continental rifting and seafloor spreading, sea level throughout the Cretaceous was much higher than it is today. Spring- The spring in the Southwest region is cool. A value between -2 and -3 indicates moderate drought, -3 to -4 is severe drought, and -4 or below indicates extreme drought. These warmer temperatures and increased precipitation have helped bring on longer growing seasons. Shiprock, a volcanic monadnock in San Juan County, New Mexico, rises roughly 483 meters (1583 feet) above the desert plain. These increased temperatures lead to a whole host of other effects, including a decrease in snowpack, declines in river flow, drier soils from more evaporation, and the increased likelihood of drought and fires. Here at the ENSO Blog, were always curious about the role of ENSO (El Nio/Southern Oscillation, the entire El Nio/La Nia system). The climate was drier than that of the Carboniferous, and mudflats with salt and gypsum formed across the Southwestern states. The formation of precipitation also causes electrical charging of particles in the atmosphere, which in turn produces lightning. Its not over yet, but possible that the overall monsoon rainfall in Arizona will end up being the highest on record. The Southwest has a hot desert climate, at lower elevations. The warmer the air near the surface is relative to the air above it, the more potential energy it has to move up. The oceans between Gondwana and North America began to close. 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). The average amount of precipitation for the United States is 85.6 centimeters (33.7 inches). 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. Used under a Creative Commons license. The elevation of Bear Lake is about 2880 meters (9450 feet). There is some variability in the onset and demise of the monsoon. 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 population of any industrialized and particularly wealthy country produces pollution; the majority of these emissions come from the use of petroleum. Data for Figure 2 were provided by the National Drought Mitigation Center. Northwestern Mexico receives upwards of 75% of its average annual precipitation from it, and Arizona and New Mexico more than 50%, during JulySeptember. Precipitation forms. 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. Although much of the Southwest falls within the category of an arid zone, using a single label to describe the Southwest's climate would belie its diversity. While two indicators in this report present information about unusually high or low temperatures and drought on a national scale (see the High and Low Temperatures indicator and the Drought indicator), this feature highlights the Southwest because of its particular sensitivity to temperature and drought. The Palmer Index is calculated from precipitation and temperature measurements at weather stations, and has been used widely for many years. 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. Map modified from amap by Chiche Ojeda (Wikimedia Commons,Creative Commons Attribution-ShareAlike 4.0 International license, image cropped and modified). Its remnant exists today as the Great Salt Lake. 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. 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). Climate models project a significant increase in the number of days over 95F per year across the Southeast. Photo by James St. John (flickr,Creative Commons Attribution 2.0 Generic license, image cropped and resized). The book was adapted for the web by Elizabeth J. Hermsen, Jonathan R. Hendricks, and Ingrid Zabel in 2022. As of June 2022, it was more than 90% contained. Water is already scarce in the Southwest, so every drop is a precious resource. Photo of USNM P 38052 by Frederic Cochard (Smithsonian National Museum of Natural History, public domain). (2019)Biology Letters15: 20190114(Creative Commons Attribution 4.0 International license, images cropped, reconfigured, resized, and relabeled). Funnel clouds (developing tornadoes) over El Paso County, Colorado, March 29, 2019. This page uses Google Analytics. Before the Isthmus closed, the Atlantic and Pacific oceans were connected. Published June 22, 2021 Updated Aug. 23, 2022. Photo by Lane Pearman (flickr, Creative Commons Attribution 2.0 Generic license, image cropped and resized). Loess is often, though not exclusively, associated with dry areas around glaciers. By comparison, the average high and low temperatures for the entire United States are 17C (63F) and 5C (41F), respectively. Accessed March 2021. https://droughtmonitor.unl.edu/DmData/DataTables.aspx. Deer mice are the most important rodent carriers of hantavirus in the Southwest. 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. 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. Share sensitive information only on official, secure websites. So is climate change increasing monsoon variability? Source:Figure 1 from Erdei et al. Photograph by Bill Morrow (Flickr;Creative Commons Attribution 2.0 Generic license). Like the Inside Passage, the weather in Southwest Alaska is heavily influenced by ocean currents and maritime conditions. A blog about monitoring and forecasting El Nio, La Nia, and their impacts. There is a rich marine fossil record from the areas between these islands. 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. Submitted by rebecca.lindsey on Thu, 09/30/2021 - 10:15, Science & information for a climate-smart nation. 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. 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. You mentioned, if I understood correctly, that a La Nina pattern during winter months leads to an increase in the North American Monsoon in late summer. Copyright 2021 Paleontological Research Institution. The size and location of various lakes in which the Green River Formation sediments were deposited during the Eocene epoch. Tornado Alley is identified. Large lakes formed in low areas, and the Southwests most striking ice age feature was Lake Bonneville, a massive pluvial lake that covered much of Utah. Monsoon region averaged over all land gridpoints, 20N37N, 102W115W. 4. A couple of field campaigns, including the Arizona-based South-West Monsoon Project (SWAMP, 1993) and the international North American Monsoon Experiment (NAME, 2004), provided a lot of observational data and resulted in a better understanding of the mechanics of the monsoon. Summer heat waves will become hotter and longer, while winter cold snaps will occur less often. Figure by Emily Becker. The current drought outlooks expect that the drought in Arizona and New Mexico will improve in the short term, but persist. Please click here to see any active alerts. Photograph by Julia Manzerova (Flickr;Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Generic license; image resized). 2021. Warm, moist air from the south occasionally but infrequently moves into Colorado during the summer. Average annual temperatures for the southwestern U.S. Forecasts had all of this widespread flash flooding. Submitted by rebecca.lindsey on Thu, 09/30/2021 - 10:14. Because warm air can hold more moisture than cool air can, convective mixing with cool air forces moisture to condense out of warm air as vapor (clouds) and precipitation. Since the early 1900s, the Southwest has experienced wetter conditions during three main periods: the 1900s, 1940s, and 1980s. Both fires began as prescribed burns, or fires that were set deliberately with the intention of preventing the formation of future wildfires. 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. Average is based on 19792020 using CPC Unified data. A .gov website belongs to an official government organization in the United States. Yet this landscape actually supports a vast array of plants and animals, along with millions of people who call the Southwest home. I did a quick comparison of the average JulyAugust rainfall in the monsoon region with the Nio-3.4 index, using 70 years of records. The final ingredient is wind. Streamflow totals for the decade of 2001-2010 in the Great Basin, Rio Grande, and Colorado River were between 5% and 37% lower than their 20. The warm, arid Southwest region presents extreme challenges to turf grasses in low- and high-desert climates. Data source: National Drought Mitigation Center, 20213Web update: April2021. MacDonald, G.M. 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. Precipitation also varies widely. Photo by Bigmikebmw (Wikimedia Commons, Creative Commons Attribution-ShareAlike 3.0 Unported license, image cropped). Data: U.S. Energy Information Administration. 2021. 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. PRI is a registered 501(c)(3) nonprofit organization. The Sonoran Desert is located in southwestern Arizona and adjacent regions of California and Mexico. 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. Scattered pockets of drier, Mediterranean temperatures can also be found. 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. (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. Carbon dioxide emissions in Arizona rose through the last three decades of the 20th century and reached a peak in 2008. 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. National Drought Mitigation Center. Images by Lauren Dauphin, NASA Earth Observatory (used following NASA's image use policy). 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. The Southwest Region climate in the United States is often associated with extremes. Monsoon rainfall activity tends to be grouped into bursts, with periods of rainy days interspersed with drier periods, rather than rain every day. As of 2010, bark beetles in Arizona and New Mexico have affected more than twice the forest area burned by wildfires in those states. In New Mexico, climate is characterized by arid, semiarid, or continental conditions, with light precipitation, low humidity, and abundant sunshine. (2015) . Photo by Stefan Klein (Wikimedia Commons, Creative Commons Attribution-ShareAlike 4.0 International license, image cropped and resized). 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. Agua Caliente solar farm, Maricopa County, Arizona. Copyright 2021 Paleontological Research Institution. Some areas were more than 2F warmer than average (see Figure 1). The summer precipitation total for the CONUS was 9.48 inches, 1.16 inch above average, ranking eighth wettest in the historical record. Moisture condenses out of the warm air as it comes into contact with cool air, forming clouds. 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). In 2020, Colorado ranked 7th in the nation for solar and wind power production, and Arizona and New Mexico ranked 12th and 13th, respectively. NASA Earth Observatory image by Lauren Dauphin (NASA Earth Observatory,used following NASA's image use policy). Calf Canyon-Hermit Creek Fire near Holman, New Mexico, on May 8, 2022. Lake Powell, the lake created by Glen Canyon Dam, at two points in time about four years apart. What happened that make TS Nora so underwhelming? Scientists first noted the seasonal rainfall patterns in the Southwest in the early 20th century, with the circulation pattern being understood as monsoonal by midcentury. Winds and waves shape the landscape, and rain showers support lush vegetation. Cities like Phoenix, Las Vegas, Yuma, and Palm Springs have average highs over 100 F (38 C) during the summer months and lows in the 70s or even 80s. Cambrian trilobites from the Bright Angel Shale (Tonto Group), Grand Canyon National Park, Arizona. The Southwest, already the driest region in the United States, has become even drier since the mid-20th century, particularly on the hottest days . Seems likely that conditions in the GM may influence annual variations in the monsoon. That timeworn classic is only partially true--May and September can also be great summer months. All rights reserved. Scale bar = 5 centimeters (about 2 inches). Of the southwestern states, Arizona emits the most greenhouse gases, releasing 92.5 million metric tons of energy-related carbon dioxide (CO2) in 2019. The Southwest has a very unique culture, climate, and geography. 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. Las Cruces, New Mexico, 2006. 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). As the Triassic period began, the Southwest moved north from the equator. Facebook Tweet Nighttime winter temperatures in the desert can drop slightly below freezing. Despite the monsoon rainfall this year, much of the region is still in a precipitation deficit. See the Drought indicator for more information about these indices. :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/. . Zack also mentioned our good friend El Nio! 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. 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. Map made by Elizabeth J. Hermsen usingSimplemapprand modified in Photoshop. 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. The ENSO blog is written, edited, and moderated by Michelle LHeureux (NOAA Climate Prediction Center), Emily Becker (University of Miami/CIMAS), Nat Johnson (NOAA Geophysical Fluid Dynamics Laboratory), and Tom DiLiberto and Rebecca Lindsey (contractors to NOAA Climate Program Office), with periodic guest contributors. Studies show that the southwestern states' climate is changing right now and that change has accelerated in the latter part of the 20th century. Unfortunately, unpredictable winds spread the flames, which, combined with dry conditions, caused the Calf Canyon and Hermit Peak fires to grow beyond control. JavaScript appears to be disabled on this computer. The American Southwest, here defined as the area between 95W and 125W and 25N and 40N, 9 covers over four million square kilometers. Climate at a glance. A lock (LockA locked padlock) or https:// means youve safely connected to the .gov website. According to the Kppen classification system, a system of climate classification using latitude band and degree of continentality as its primary forcing factors, Central Asia is a predominantly B-type climate regime. Mesohippusmeasured up to 70 centimeters (2 feet) at shoulder height. Photo by Jeffrey Beall (Wikimedia Commons,Creative Commons Attribution 4.0 International license, image resized). [7] Pion pines are very drought tolerant and have survived dry periods in the past. The event devastated the Southwest, shifting a densely forested landscape to one primarily covered with fast-growing herbs and ferns. 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.