Latest Seasonal Assessment -
Near- to above-normal precipitation during the past 30 days once again prevailed across the eastern half of the Nation, leaving only moderate drought in southeastern Florida, northern North Dakota, and small areas of northern and southern Texas. Since the Dec. 11 U.S. Drought Monitor, all drought was removed from eastern Oklahoma, southwestern Missouri, and northwestern Arkansas, and was reduced in northern North Dakota. In contrast, a few areas in the eastern half of the lower 48 States measured less than half of normal precipitation since mid-December, allowing for the development of moderate drought in south Texas and the persistence of D1 in north Texas and southeastern Florida. In the West, surplus 30-day precipitation across most of the Southwest (southern California, Arizona, New Mexico, southern Colorado) and near- to above-normal precipitation in the Pacific Northwest (most of Oregon and Washington) was enough for a 1-category improvement in parts of these States. Some regions, however, observed subnormal precipitation, especially in the north-central Rockies and High Plains, and some slight expansion of dryness and drought was made in northern Colorado, southern Wyoming, and central Idaho. Fortunately, 30-day temperatures averaged near to below normal, allowing much of the precipitation to fall as snow and build the basin's snow pack and snow water content (SWC). As of Jan. 14, most major basin average WYTD SWC in the southern half of the West ranged between 80-110 percent of normal (basin average WYTD precipitation 80-120 percent), better than previous winters but not enough (yet) to make a serious dent in the long-term drought in the Four Corners Region. In the northern half of the West, basin average SWC was generally lower (60-90 percent), as was precipitation (65-90 percent).
While the El Niño Watch was still in effect (65 percent chance that El Niño was expected to form and continue through the Northern Hemisphere spring 2019), the atmospheric anomalies largely reflected intra-seasonal variability related to the Madden-Julian Oscillation, and have not yet shown a clear coupling to the above-average ocean temperatures. However, the late winter and early spring tend to be the most favorable months for coupling, so forecasters still believe weak El Niño conditions will emerge shortly, but given the timing and that a weak event is favored, significant global impacts are not anticipated during the rest of the winter even if conditions were to form. With that said, late January into February is expected to feature a strong ridge over the West and deep trough over the East, with favorable odds for subnormal precipitation in the West (above-normal temperatures) and Ohio/Tennessee Valleys (subnormal temperatures). Similar precipitation and temperature patterns are forecast for FMA, except for a tilt toward above-normal precipitation in the south-central Rockies and Plains and along the eastern Gulf and southern Atlantic Coast States. Southern Alaska is expected to be wet and mild at all periods, while El Niño typically brings subnormal rainfall to the leewards of Hawaii and the Caribbean (Puerto Rico). Accordingly, drought should persist or develop in the Northwest, California, and Great Basin, the leewards of Hawaii, and in parts of Puerto Rico, while some improvement is expected in the Four Corners Region, northern and southern Great Plains, southern Florida, and southeastern Alaska.
Forecaster: David Miskus
Next Seasonal Outlook issued: January 17, 2019 at 8:30 AM EST
Seasonal Drought Outlook Discussion