National Drought Summary -- July 18, 2019

Hurricane Barry made landfall in southern Louisiana on July 13, delivering locally heavy showers and a modest storm surge but largely sparing crops and communities in the path of the poorly organized storm. Once inland, Barry drifted northward and was quickly downgraded to a tropical storm and—by July 14—a tropical depression. Outside of Barry’s sphere of influence, locally heavy showers dotted the Southeastern and Mid-Atlantic States, sparking local flooding. Locally heavy rain also soaked portions of the North, with some of the highest totals reported across the northern half of the Plains and the upper Midwest. Many other areas of the country, including a large expanse of the West and parts of the southern Plains and the Midwest, experienced warm, dry weather. In fact, near- or above-normal temperatures dominated the country, as mid-summer heat began to build. Areas affected by Barry’s remnants, including the mid-South, remained somewhat cooler due to cloudy, showery weather. In part due to mid-July heat, short-term dryness was of great concern across the lower Midwest, where compaction, crusting, and dryness was reported in previously saturated topsoils.

By mid-July, more than 50 active Alaskan wildfires had collectively scorched well over 1.2 million acres of vegetation. In addition, record-setting heat continued to bake parts of Alaska. From July 8-10, McGrath reported a trio of daily-record highs (89, 84, and 85°F). On July 9, daily-record highs were also set in locations such as Fairbanks (87°F) and Nome (83°F). For Nome, it was the highest reading since July 7, 2014, when the temperature had reached 84°F. Given the heat and short-term dryness, abnormal dryness (D0) was broadly expanded across the Alaskan interior. In addition, moderate drought (D1) greatly increased in coverage across east-central Alaska and was introduced on the Kenai Peninsula. Meanwhile, moderate to extreme drought (D1 to D3) persisted or expanded slightly across southeastern Alaska, where a variety of impacts ranging from reduced hydroelectric power generation to fish mortality have been reported. Farther south, parts of Hawaii continued to benefit from earlier rainfall, resulting in the elimination of moderate drought (D1) from Kauai, Oahu, and Molokai. However, some severe drought (D2) was added across the northern part of the Big Island. In addition, all of Hawaii continues to deal with elevated temperatures due to unusually warm water surrounding the islands. On Maui, Kahului’s high temperatures reached or exceeded 90°F each day from June 21 to July 16. Elsewhere, there were only slight changes made to the drought depiction in Puerto Rico—the removal of abnormal dryness (D0) along part of the northern coast and a slight increase in moderate to severe drought (D1 to D2) along the south-central coast. In San Juan, Puerto Rico, significant rainfall deficits exist at many time scales. For example, San Juan received 4.46 inches (63% of normal) from June 1 – July 16 and through the 16th had a year-to-date total of 14.78 inches (57% of normal).

Heavy showers and thunderstorms sweeping across North Dakota eradicated severe drought (D2) and reduced the coverage of moderate drought (D1) and abnormal dryness (D0). In the Dakotas, daily-record amounts for July 9 totaled 3.12 inches in Williston, North Dakota, and 1.29 inches in Watertown, South Dakota. The remainder of the High Plains remained free of dryness and drought.

The Midwest remained free of drought, but several areas were being watched for possible future introduction of abnormal dryness (D0). By July 14, USDA reported that topsoil moisture ranged from 19 to 26% very short to short in Illinois, Indiana, Michigan, Missouri, and Ohio. Due to antecedent wetness resulting in soil compaction, as well as late-planted crops such as corn and soybeans exhibiting poor root development, drought-related impacts could develop very quickly during the summer of 2019. During the last 2 weeks, mostly dry weather has prevailed in a broad area centered on northern Missouri and southern Iowa; this area and other dry Midwestern pockets will be closely monitored. Meanwhile, upper reaches of the Midwest received heavy showers and thunderstorms, which resulted in a reduction in the coverage of abnormal dryness (D0) across northern sections of Michigan, Minnesota, and Wisconsin.

Abnormal dryness (D0) has begun to develop in parts of southern New England and environs. On July 14, the U.S. Department of Agriculture (USDA) reported topsoil moisture 95% short in Connecticut. Based on short-term precipitation deficits and low streamflow values, a spot of D0 was introduced in western sections of Connecticut and Massachusetts, as well as a tiny sliver of eastern New York. From June 1 – July 16, rainfall in Hartford, Connecticut, totaled just 2.71 inches (43% of normal). During the same 46-day period, Poughkeepsie, New York, received 3.85 inches (58% of normal).

Hurricane Barry erased dryness (D0) from Louisiana and nearly so from Mississippi. There was also a reduction in D0 coverage in Tennessee. Meanwhile, hot, dry weather covered much of southern Texas, leading to expansion of dryness (D0) and moderate to severe drought (D1 to D2). July 11 featured a daily-record high in Brownsville, Texas (100°F). Elsewhere in Texas, Corpus Christi posted three consecutive daily-record highs (101, 101, and 103°F) from July 11-13. Brownsville noted another daily-record high, 102°F, on July 13.

Pockets of dryness (D0) and moderate drought (D1) persisted from the Carolinas southward, with some areas receiving heavy showers and other remaining mostly dry. A couple of small areas of severe drought (D2) stretched from northwestern Florida to southwestern Georgia, including portions of southeastern Alabama. Showers associated with the remnants of Hurricane Barry were heaviest across western Alabama. In southeastern Alabama, however, Dothan’s rainfall from June 1 – July 16 totaled 4.83 inches (55% of normal). On July 14, USDA reported that topsoil moisture was 41% very short to short in Georgia and 30% very short to short in Alabama. On the same date in North Carolina, 30% of the corn for grain was rated in very poor to poor condition.

Minimal changes were made, although generally cool weather in the Northwest contrasted with hot conditions in the Southwest. A few monsoon-related showers developed in the Four Corners States—the official monsoon start date in Tucson, Arizona, based on average dewpoint temperature, was July 13, the latest onset in that location since 2005. Meanwhile in eastern Washington, moderate drought (D1) was expanded due to an evaluation of water year-to-date precipitation totals; low reservoir levels; and soil moisture shortages. On July 14, USDA rated topsoil moisture 62% very short to short in Oregon and 39% very short to short in Washington.

Heat and high humidity levels will dominate the central and eastern U.S. through week’s end, except on the northern Plains. By early next week, however, markedly cooler, drier air will arrive across the Plains and Midwest. Meanwhile, the post-tropical remnants of Hurricane Barry will spark showers in the East through Thursday, while scattered showers and thunderstorms will affect parts of the nation’s northern tier. Five-day rainfall totals could reach 2 to 4 inches in the upper Midwest and locally 1 to 3 inches east of the Mississippi River. In contrast, dry weather will prevail in the south-central U.S. and from California to the Intermountain West.

The NWS 6- to 10-day outlook for July 23 – 27 calls for the likelihood of below-normal temperatures from the central and southern Plains to the Atlantic Seaboard, excluding southern Florida, while hotter-than-normal conditions will dominate the West and the northern High Plains. Meanwhile, below-normal rainfall in the Midwest and along the northern Pacific Coast should contrast with wetter-than-normal weather along the Atlantic Coast, in the Deep South, and across the Intermountain West.