Most of the U.S. Is Experiencing Record-Low Drought Levels

Frederic J. Brown/AFP/Getty Images
Frederic J. Brown/AFP/Getty Images

This winter, relentlessly wet weather patterns bathed the United States with much-needed water. As a result, drought levels in the United States are at their lowest since Y2K, according to an analysis released by the United States Drought Monitor (USDM). Only 5.4 percent of the country is experiencing drought conditions right now, the lowest level on record since the USDM began a weekly analysis of abnormally dry conditions on January 4, 2000.

The USDM’s job is to measure the severity of a region’s dryness based on data like observed rainfall, soil moisture, streamflow, and water levels in lakes and reservoirs. This precipitation data is categorized on a five-point scale that ranges from “abnormal dryness,” the lowest category, to “exceptional drought”—reserved for the worst and longest-lasting drought conditions.

About 12 percent of the country is experiencing “abnormally dry” conditions, usually indicative of fleeting dryness that can often be remedied with a decent afternoon of soaking rain. The regions still thirsting for water are mostly in the southeastern United States, where widespread severe drought conditions persist over central and southern parts of Florida. The worst drought conditions exist there and over the mountains of northern Georgia, a tiny area that’s seen a rainfall deficit of 8 to 12 inches since last fall. But drought conditions across the rest of the country are largely scattered and limited in both scope and duration.

A major contributing factor to these delightfully low drought levels is California’s incredible reversal in fortunes this past winter. The state endured a devastating, years-long drought that abruptly came to an end after a steady train of storms rolled ashore and produced copious amounts of rain and snow. Much of central and northern parts of California have seen rainfall amounts of 1 to 2 feet above normal over the past six months. The Sierra Nevada mountain range in particular has seen more than 100 inches of snow this season, erasing previous years’ snowfall deficits and building up a significant reserve of meltwater to replenish downstream reservoirs when the warmth of summer takes hold.

Ironically, areas that were too dry not too long ago are now trying to cope with too much rainfall. North Carolina was hit especially hard toward the end of April, when a slow-moving storm system dropped more than 6 inches of rain across some of the most populated parts of the state. The heavy, steady rain mostly erased the state’s rainfall deficit in one weekend, but it also caused some major flooding problems. Raleigh, North Carolina, for example, found itself in a “flash flood emergency” on April 25, 2017, after excessive rains swelled local waterways beyond their banks and threatened homes, businesses, and major thoroughfares. When it comes to rain, as with everything in life, moderation is the goal.

Storm Leaves Homes Along Lake Erie Covered in Up To Three Feet of Ice

Houses along Lake Erie's shoreline were pummeled with sheets of icy water during a storm last week.
Houses along Lake Erie's shoreline were pummeled with sheets of icy water during a storm last week.
John Normile/Getty Images

This past weekend, lakeside residents of Hamburg, New York, awoke to find their neighborhood transformed into a full-scale replica of Frozen’s ice-covered kingdom, Arendelle.

According to CNN, gale force winds produced giant waves that sprayed the houses along Lake Erie with sheets of water for two days straight, covering them in layers of ice up to three feet thick.

“It looks fake, it looks surreal,” Hamburg resident Ed Mis told CNN. “It’s dark on the inside of my house. It can be a little eerie, a little frightening.”

While the homeowners are anxious for the ice to melt, they’re also concerned about what could happen when it does.

“We’re worried about the integrity, of structure failure when it starts to melt, because of the weight on the roof,” Mis said.

He added that this is the worst ice coating he’s seen since he moved to the area eight years ago—but it’s not because they’ve had a particularly harsh winter. In fact, just the opposite is true. According to The Detroit News, warm winter temperatures have caused ice cover on the Great Lakes to drop from 67 percent in 2019 to less than 20 percent this year.

“Lake Erie typically has significant ice cover by this time of the year, and that protects the shoreline from these battering storms,” The Weather Channel’s winter weather expert Tom Niziol explained in a video.

The phenomenon has created another unforeseen issue for Hamburg’s coast, too: Tourism. The local police department posted a message on Facebook on Sunday, March 1, asking people to keep off both the “extremely unsafe and unstable” ice and people's private property.

[h/t CNN]

What is Lake-Effect Snow?

Tainar/iStock via Getty Images
Tainar/iStock via Getty Images

As you probably guessed, you need a lake to experience lake-effect snow. The primary factor in creating lake-effect snow is a temperature difference between the lake and the air above it. Because water has a high specific heat, it warms and cools much more slowly than the air around it. All summer, the sun heats the lake, which stays warm deep into autumn. When air temperatures dip, we get the necessary temperature difference for lake-effect snow.

As the cool air passes over the lake, moisture from the water evaporates and the air directly above the surface heats up. This warm, wet air rises and condenses, quickly forming heavy clouds. The rate of change in temperature as you move up through the air is known as the "lapse rate"; the greater the lapse rate, the more unstable a system is—and the more prone it is to create weather events.

Encountering the shore only exacerbates the situation. Increased friction causes the wind to slow down and clouds to "pile up" while hills and variable topography push air up even more dramatically, causing more cooling and more condensation.

The other major factors that determine the particulars of a lake-effect snowstorm are the orientation of the wind and the specific lake. Winds blowing along the length of a lake create greater "fetch," the area of water over which the wind blows, and thus more extreme storms like the one currently pummeling the Buffalo area. The constraints of the lake itself create stark boundaries between heavy snow and just a few flurries and literal walls of snow that advance onto the shore. The southern and eastern shores of the Great Lakes are considered "snow belts" because, with winds prevailing from the northwest, these areas tend to get hit the hardest.

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