Latest Monthly Assessment -
Despite the ongoing La Niña conditions, which are typically associated with reduced winter precipitation across California, a persistently negative Pacific North America (PNA) pattern during December promoted frequent storminess tracking south from the Gulf of Alaska to California. These storms brought widespread above-average snows to the Cascades, Sierras, coastal ranges, and to a lesser extent the Rockies, with heavy rainfall at lower elevations boosting streamflows and causing some flooding impacts. While drought conditions still blanket most of the West, the beneficial precipitation reduced the intensity of the drought across wide areas west of the Continental Divide. Further east, mostly dry conditions and much above normal temperatures caused an unusually rapid December drought expansion across the central and southern Plains, lower Mississippi Valley, and the South Atlantic states, while periods of storminess and not yet frozen streams allowed some relief across the upper Midwest. During January, the updated CPC temperature and precipitation guidance indicates a colder pattern for the northern tier, with enhanced precipitation favored for the Northwest and northern Rockies. In contrast, abnormal warmth and dryness are favored to persist across the south-central US and along the Gulf Coast. Heavy precipitation in early January coupled with the wetter signal on the monthly time scale favor continued easing of drought across the Northwest and northern Rockies, while near term precipitation events may bring localized relief to southern California and southern Arizona and New Mexico. Drought expansion is favored to continue across central Texas, Louisiana, and parts of the Florida Panhandle. Across the East, wet weather in early January may be sufficient to slow the advancement of drought, but accumulations are not expected to be sufficient to promote widespread relief. An active pattern across the upper Midwest and Great Lakes region may yield some improvements where streams remain unfrozen, but most areas have frozen soils and streams, which will delay the impacts of any precipitation that falls during January.
Drought conditions have eased substantially across Hawaii, and an anticipated continuation of storminess and enhanced trade winds favors removal of the remaining drought areas. La Niña winter months are typically dry across the Caribbean, but mixed signals in the dynamical model forecasts precludes a forecast for continued drought expansion across Puerto Rico. No drought is currently in place or forecast to develop across Alaska, with cold conditions favored during January.
Forecaster: Adam Allgood
Next Monthly Drought Outlook issued: January 31, 2022 at 3pm EST
Monthly Drought Outlook Discussion