Meanwhile Moderate Drought (D1) was expanded from northwestern Nevada eastward across north-central Utah and into portions of northwestern and central Colorado, despite the arrival of some much-needed rain and snow. Even with the precipitation, which totaled a half inch or less at lower elevations to locally more than an inch (liquid equivalent) in the mountains, additional detailed assessment led to a general increase in drought designation. Water-year precipitation is running 50 percent of normal or less from northwestern and central Nevada eastward into Utah and Colorado. In particular, snow-water equivalent percentile rankings range from: 3rd to 15th percentile in east-central Nevada; 10th to 30th percentile in Utah’s central Wasatch and less than the 20th percentile in the Uinta Mountains; and 3rd to 30th percentile in northwestern and central Colorado. Further illustrating the dryness are the 3- and 6-month Standardized Precipitation Indices, which both depict D1 (or worse) conditions in the newly-expanded Moderate Drought (D1) region.
Across the southern Rockies and Southwest, no changes were made to the current drought classification. Precipitation in the shorter term (60 to 90 days) has been generally sufficient to prevent drought intensification, with current snow-water equivalent in the 40th percentile or higher over much of Arizona and New Mexico.
Alaska, Hawaii, and Puerto Rico: In Alaska, bitterly cold conditions continued, with temperatures averaging more than 20°F below normal. Snow continued to fall across the southern half of the state, with no concerns for drought. In Hawaii, much of the state was dry, although rain was reported on Kauai. With the ongoing dryness and reports of pastures in very poor condition, Extreme Drought (D3) was expanded northward on the Big Island, while Abnormal Dryness (D0) was expanded to encompass all areas from Oahu to the Big Island. On Puerto Rico, light to moderate showers (1-2 inches, locally more) fell across the northeastern quarter of the island, with no drought concerns at this time.
Looking Ahead: A moisture-laden storm system will provide widespread, locally heavy rain from central and eastern Texas into the Delta and Southeast, although rain is expected to diminish as a trailing cold front sweeps across Florida. Rain will also fall in the Mid-Atlantic and Northeast, with snow likely in northern New England. Meanwhile, the last in a rapid succession of Pacific storms will bring additional rain and mountain snow to the Northwest as well as the central and northern Rockies. Generally dry weather is expected to return to California and the Southwest. The NWS 6- to 10-day outlook for January 31 – February 4 calls for above-normal temperatures over much of the contiguous U.S., with cooler than normal conditions confined to southern Florida. Drier-than-normal weather is expected from the central and southern Rockies into California and from the southern Delta into the southern Atlantic Coast. Meanwhile, above-normal precipitation is anticipated from the central Corn Belt into the Great Lakes Region.
Author: Eric Luebehusen, U.S Department of Agriculture
D0 ... Abnormally Dry ... used for areas showing dryness but not yet in drought, or for areas recovering from drought.
Drought Intensity Categories
D1 ... Moderate Drought
D2 ... Severe Drought
D3 ... Extreme Drought
D4 ... Exceptional Drought
Drought or Dryness Types
S ... Short-Term, typically <6 months (e.g. agricultural, grasslands)
L ... Long-Term, typically >6 months (e.g. hydrology, ecology)