Nationwide
On January 9 and 10, a low-pressure system tracked along the Gulf Coast, resulting in widespread precipitation (1 to 2.5 inches, liquid equivalent) from eastern Texas and the Lower Mississippi Valley east to the Florida Panhandle.
On the northern extent of this storm, snow blanketed areas from Oklahoma and Arkansas to north Georgia. This precipitation during the second week of January supported drought improvement. However, drought expanded and intensified for the Florida Peninsula, eastern North Carolina, west-central Texas, and the Southwest. During the first two weeks of January, multiple Arctic surface highs shifted south from Canada and temperatures (January 1-13) averaged 4-8 F below normal for much of the Great Plains, Middle to Lower Mississippi Valley, and Southeast. A very dry start to the wet season continued to affect southern California with worsening drought conditions, periodic Santa Ana winds, and large wildfires.
The West
Severe drought (D2) was expanded to include all of southern California due to the very dry start to the water year to date (WYTD) from October 1, 2024, to January 13, 2025.
The D2 coverage coincides with where WYTD precipitation has averaged less than 5% of normal. A number of locations, including San Diego, are having their driest start to the water year. The D2 covers Los Angeles and Ventura counties, affected by periodic Santa Ana winds drying out vegetation and large wildfires. Following the two wet winters, the large reservoirs throughout California are at or above normal.
Based on 90-day SPI, declining soil moisture, and low snow water equivalent, a one-category degradation was warranted for parts of Arizona and southwestern Utah. Idaho received a mix of improvements and degradations, and the depiction is generally consistent with the 2024-2025 WYTD precipitation and snowpack. Eastern Washington and much of Oregon are drought-free, but low snowpack supports moderate drought (D1) along the northern Cascades of Washington.
A 1-category improvement was justified for a portion of central Montana, based on 90-day SPEI along with snow water equivalent (SWE) above the 75th percentile. As of January 14, SWE was above normal (period of record: 1991-2020) across the southern Cascades along with eastern Oregon and southwestern Idaho. SWE varies for the Sierra Nevada Mountains, and those numbers are beginning to decrease after a drier-than-normal start in January. SWE remained well below normal across the Four Corners Region.
The High Plains
The Central High Plains continued to have worsening drought conditions, and moderate drought (D1) was expanded across portions of southwestern Nebraska using the 60-day Standardized Precipitation Index (SPI), soil moisture below the 10th percentile, and the NDMC short-term blend. Although light precipitation (less than 0.5 inch, liquid equivalent) fell across parts of south-central to southeastern Kansas, this precipitation was too low to justify any improvements. Elsewhere, across the Central to Northern Great Plains, no changes were made as early to mid-January is a dry time of year. D1 was expanded across southwestern Colorado due to low snow water equivalent and 60-day SPI.
The South
More than 1 to 1.5 inches of precipitation (liquid equivalent) supported improvements for portions of eastern Texas, Arkansas, Louisiana, and Mississippi.
The small areas of severe drought (D2) were discontinued in northeastern Mississippi due to 28-day average streamflows near the 20th percentile, soil moisture recovery, and a consensus of SPIs in D1 at worst. In addition, there is no support for maintaining D2 in the NDMC short- and long-term blends. Precipitation during the first two weeks of January slightly reduced extreme drought (D3) across south-central Tennessee.
For central Texas, which received generous precipitation for this time of year, low 28-day streamflows (below the 20th percentile in D1 and 10th percentile in D2) precluded a larger area for a 1-category improvement. D2 to D3 drought was expanded across the Edwards Plateau of Texas due to 28-day average streamflows below the 10th and 5th percentile, respectively. — UNL Drought Monitor
