Drought Shows Some Improvement As Spring Turns Stormier
In the last week, a few swaths of precipitation occurred across the country, including the Sierra Nevada, northwest California and western portions of Washington and Oregon. Some high elevation areas of the West received precipitation as well, mostly outside of the Desert Southwest. Some areas of the Upper Midwest and Northeast received a quarter of an inch of precipitation to locally over an inch. A powerful storm moved across much of the nation from March 3rd to March 5th, delivering thunderstorms and high winds from Texas to the Midwest, Southeast and East Coast; and snowfall in the north-central U.S. This moderate precipitation will not be accounted for until next week’s drought update.
West
Precipitation fell across higher elevations of California, northern Idaho and western areas of Oregon and Washington this week. For the most part, drier weather occurred elsewhere. Recent improvements to snowpack in northeast Nevada, Idaho and southwest Montana led to localized improvements to drought conditions. Meanwhile, to the south across Utah, Arizona and New Mexico, this week’s continued dry weather led to widespread drought degradation as short- and long-term precipitation deficits grew amid soil moisture, streamflow and groundwater deficits. Drought conditions are especially bad from Phoenix westward to far southeast California, where exceptional drought developed this week.
High Plains
Some precipitation fell in mountainous areas of Colorado and Wyoming, and snow occurred Monday night into Tuesday morning in parts of the northeast Colorado plains into western and central Nebraska. Most of the High Plains region east of the Rocky Mountains did not see any changes to ongoing drought or abnormal dryness, except for southern Kansas, where abnormal dryness expanded in response to unusually dry weather in the last few months. In western Colorado, moderate and severe drought expanded in coverage due to very low snowpack and growing precipitation deficits. Extreme drought (D3) remains across southeast Wyoming, northwest Nebraska, and the southwest part of South Dakota.
Midwest
A half inch or more of precipitation fell across parts of northern Ohio, north-central Illinois and the Upper Peninsula of Michigan, while most other areas were relatively dry this week. Growing precipitation deficits, especially in the short-term, combined with low streamflow and soil moisture, led to the expansion and development of moderate and severe drought in northern Missouri, central and northern Illinois and Indiana. Luckily, much of this area recorded precipitation on March 4th, so future updates may show some improvements in this area. Elsewhere in the Midwest, low seasonal snowfall totals in parts of Minnesota are of growing concern as the transition to spring occurs.
South
A line of thunderstorms associated with this week’s powerful low-pressure systems produced widespread rain of 0.5-1 inches in central and western Oklahoma and central north Texas, though areas east of there did not receive precipitation from this storm system until after the data cutoff. Scattered drought degradations occurred in the western halves of Texas and Oklahoma, due to increasing precipitation deficits and locally decreasing streamflow and soil moisture. Groundwater and reservoir levels continued to drop in central Texas in the San Antonio area amid very large precipitation deficits, leading to the development of a small area of exceptional drought. Similar conditions in southwest Texas led to the expansion of exceptional drought along the Rio Grande to the El Paso area.
Southeast
Most areas in the region had a dry week. Short- and long-term moderate and severe drought developed or expanded across parts of the Carolinas and eastern Georgia this week, where streamflow and soil moisture dropped amid increased precipitation deficits. Smaller-scale increases in abnormal dryness and moderate drought occurred in Alabama after the dry week. Short-term moderate and severe drought expanded in south Florida, where fire danger indices have increased recently. Some improvements to short-term moderate drought occurred in central Florida following heavy rainfall that fell near the data cutoff time.
Northeast
Precipitation amounts this week varied from a quarter inch to locally over an inch from western Pennsylvania and West Virginia through New England, while mostly dry weather occurred elsewhere. Few changes were made to the drought depiction this week in the Northeast. Short- and long-term severe drought expanded a bit in central Maryland and adjacent south-central Pennsylvania, where soil moisture conditions continued to worsen alongside decreasing streamflow and increasing precipitation deficits. The entire state of New Jersey is under moderate (D1) to severe (D3) drought.
Looking Ahead
Forecast trends through the weekend and Monday indicate that California and portions of the high elevation West will receive 0.75 or more inches of precipitation, though this is mostly expected to miss New Mexico, Montana, northern Idaho, Washington and Oregon. A few other corridors of at least a half inch of precipitation are forecast across northern Nebraska, from southeast Oklahoma to South Carolina and the Florida Panhandle, and in New England. Some areas of the Southeast may receive at least 1 inch of rainfall.
Above-normal precipitation is favored in the northern contiguous U.S. and strongly favored in the western, and especially southwestern, U.S. Below-normal precipitation is favored in most of Texas, especially in far southern reaches of the state. This active storm track across the U.S. is likely to continue through at least March 20th.
