This Week’s Drought Summary
A broad area of surface high pressure resulted in little to no precipitation throughout the contiguous U.S. from February 8 to 14. During this 7-day period, the most significant precipitation (more than 0.5 inch, liquid equivalent) was limited to the Cascades, Upper Mississippi Valley, northern New England, and the Florida Peninsula. Following a wet December with beneficial snowfall, a persistent area of mid-level high pressure anchored near the West Coast led to drier-than-normal conditions across the western U.S. since early January. During the second week of February, above-normal temperatures prevailed throughout the West and much of the Great Plains. Drier weather returned to Puerto Rico by mid-February, while enhanced trade wind showers resumed across the eastern side of Hawaii’s Big Island.
Based on 90-day SPI values and soil moisture indicators, a 1-category degradation was made to parts of Arkansas and adjacent northwest Mississippi. Impacts related to these worsening drought conditions include dry ponds and continued high fire danger. The previous week’s D2 areas in southwest Mississippi and adjacent Louisiana were merged and slightly expanded eastward, consistent with SPoRT soil moisture percentiles, 28-day average streamflows, and 90-day SPI values. Precipitation deficits of more than 8 inches are observed during the past 90 days across a broad area of the Lower Mississippi Valley. Statewide precipitation across Mississippi during November-December-January was the driest since 1985/86. On February 15, a statewide burn ban was issued for Louisiana. An expansion of extreme drought (D3) was made across north-central Oklahoma, based on 90-day SPI and worsening soil moisture indicators. Persistent dryness along with periods of above normal temperatures and enhanced winds this winter prompted an expansion of severe to extreme drought (D2 to D3 ) across the middle Rio Grande Valley. Despite a dry week, a reassessment of SPI values at various time scales and soil moisture indicators supported a 1-category improvement from moderate drought (D1) to abnormal dryness (D0) across the southern Edwards Plateau. According to the USDA’s National Agricultural Statistics Service, 77 percent of the topsoil moisture was rated as poor to very poor across Texas as of February 13. Nearly two-thirds of oats, winter wheat, and rangeland and pastures were rated in poor to very poor condition.