Climatology

Subcategories:
  • No categories
Clear

Entry Category: Climatology

Climate and Weather

Officially classified by climatologist Wladimir Köppen as having a humid sub-tropical climate, Arkansas is indeed humid, but numerous weather extremes run through the state. Humid sub-tropical is classified generally as a mild climate with a hot summer and no specific dry season. The Köppen classification is correct in that regard, but the state truly has four seasons, and they can all range from fairly mild to incredibly extreme. The topography of the land and its proximity to the plains to the west and the Gulf of Mexico to the south play a crucial role in its climate and weather. In the United States, warm, moist air travels into the plains from the Gulf of Mexico and interacts with cool, dry …

Climate Change

The spring of 2019 brought record flooding along the Arkansas River from Van Buren (Crawford County) to its confluence with the Mississippi River in the east. Historic crests occurred at Dardanelle (Yell County), Morrilton (Conway County), Toad Suck Lock and Dam near Conway (Faulkner County), and Pendleton (Desha County) between May 30 and June 6. In July 2019, the National Weather Service reported that the remnants of Hurricane Barry dumped 16.17 inches of rain on Dierks (Howard County), the most rain ever measured in a twenty-four-hour period (1:00 p.m. July 15 through 1:00 p.m. July 16) in Arkansas; the three-day total of 16.59 inches was the most rain associated with a tropical system in recorded state history. Murfreesboro (Pike County) …

Derechos, Squall Lines, Downbursts/Microbursts, and “Rogue” Winds

While Arkansas makes national news far more often for its tornadoes, the state suffers its fair share of what are commonly known as straight-line winds. For example, on June 5, 2014, a weather event originating in Colorado crossed northeastern Arkansas, killing two people, derailing a train in Craighead County, and leaving thousands without power. A derecho (pronounced “deh-REY-cho”) is an event that consists of winds that create a swath of damage that extends for more than 240 miles, has minimal wind gusts of at least fifty-eight miles per hour (mph) for most of this swath, and includes multiple hurricane-force (seventy-five mph or greater) gusts. Derechos originate from what are commonly called “bow echoes,” named for their curved radar signature. About …

Tornado Outbreak of 1952

The tornado season of 1952 was a particularly eventful one throughout the state. Twenty-six tornadoes were reported to have touched down in Arkansas from January to November that year. While twenty-six is well below the modern average of about thirty-nine tornadoes per year in Arkansas, an unusually large number of these storms in 1952 were EF-3 and stronger on the Enhanced Fujita Scale used to rate the strength of tornadoes (the ratings go from EF-0 to EF-5). Of the twenty-six tornadoes in this outbreak, at least five were rated EF-4. Among these tornadoes, the most deadly and most widely reported was the March 21, 1952, EF-4 tornado that struck White County on March 21. Over the course of the year, …

Tornado Outbreak of March 1, 1997

The tornado outbreak of March 1, 1997, was one of the deadliest in the history of the state of Arkansas. Sixteen tornadoes tracked across the state, killing twenty-five Arkansans. Several of the tornadoes had unusually long tracks, traveling between fifty and seventy-five miles. There was also a higher than statistically expected number of tornadoes of F3 strength or higher—that is, tornadoes with wind speeds in excess of 158 miles per hour. Of the sixteen tornadoes, four were responsible for all fatalities in the state, as well as much of the property damage. All sixteen tornadoes were produced by four supercell thunderstorms, with the four killer tornadoes being spawned from two such storms that formed ahead of a cold front. The …

Tornadoes

Tornadoes—destructive, violently spinning vortices of air extending from high within severe thunderstorms to the surface of the earth—are more common in the United States than anywhere else on the planet. They are particularly prevalent in the area known as “Tornado Alley,” where the proper ingredients come together: a combination of warm, moist air from the Gulf of Mexico pulled northward by storm systems dragging strong continental cold air from Canada. While Arkansas is not normally included on maps of the infamous Tornado Alley, which is usually considered to stretch from north Texas northward through Oklahoma, Kansas, and Nebraska, the state has suffered many devastating tornado outbreaks. In January 1999, Arkansas recorded the most tornadoes on any individual January day in …

Tropical Cyclones

aka: Tropical Storms and Depressions
As defined by the National Hurricane Center, a tropical cyclone is a “rotating, organized system of clouds and thunderstorms that originates over tropical or subtropical waters and has a closed low-level circulation.” Types of tropical cyclones are classified in terms of wind speed: A tropical depression is a tropical cyclone with maximum sustained winds of 38 miles per hour (mph) or lower. A tropical storm is a tropical cyclone with maximum sustained winds of 39 to 73 mph. A hurricane is a tropical cyclone with maximum sustained winds of 74 mph or higher. A major hurricane is tropical cyclone with maximum sustained winds of 111 mph or higher. Given the landlocked, central location of the state of Arkansas, it may …

Weather in the Civil War

Drought, flooding, bone-chilling winters, and intense summer heat all had an impact on the civilian and military populations of Arkansas during the Civil War, affecting military campaigns, access to food and supplies, and health conditions throughout the state. The Civil War was fought just after the end of a meteorological period that climate historians often call the Little Ice Age. This era, lasting roughly from 1300 to 1850, featured frequent climatic shifts, with bitterly cold winters switching to periods of heavy spring flooding, often followed by mild winters and subsequent droughts. While the trend toward cooling that characterized the Little Ice Age had moved toward warming by the 1860s, Civil War Arkansas would be plagued by temperature fluctuations that could …