During January, above-average temperatures were observed across much of the West. Several cold air outbreaks impacted the East, especially early in the month. This resulted in many states from the Southern Plains to Midwest and Southeast having monthly temperatures below average. In addition to the cold, several storms brought snow to parts of the Deep South. Most of the nation experienced near- to below-average precipitation during January with parts of the Southwest, Great Plains and Southeast being much drier than average. Above-average precipitation was observed in the Northwest, Central Plains and Northeast. The warm and dry conditions in much of the West limited snow totals for many locations, except for the Northwest and Northern Rockies. According to NOAA's National Snow Analysis, on January 1st, 41.9 percent of the contiguous U.S. had snow on the ground — the high elevations in the Northwest, much of the Central and Northern Rockies stretching into the adjacent Plains, Midwest and Northeast. An active storm pattern mid-month brought the snow cover to 53.7 percent on the 18th, the monthly peak. By the end of the month, 25.8 percent of the U.S. had snow on the ground — the Sierra Nevada and Cascade Mountains, the Northern and Central Rockies, parts of the Northern Plains, Upper Midwest and Northeast.

CONUS snow cover anomalies
U.S. Janember Snow Cover Extent Anomalies
Source: Rutgers Global Snow Lab

According to NOAA data analyzed by the Rutgers Global Snow Lab, the monthly snow cover across the contiguous U.S. was 1.33 million square miles, 35,900 square miles below the 1981-2010 average. This was the 21st smallest January snow cover extent in the 52-year satellite record and smallest since 2015. Above-average snow cover was observed in the Central and Northern Plains, Midwest, Northeast, and parts of the Mid-Atlantic. Below-average snow cover was observed for much of the West and Southern Plains.

Western US Mountain Snowpack
February 1 Mountain Snowpack
Source: USDA

Melting of winter and spring mountain snowpack provides a crucial summer water source across much of the western United States. The total annual water budget for agriculture and human use in the mountainous West is highly dependent on the amount of snow melt that will occur in spring and is proportional to the amount of snow on the ground. On February 1st, below-average snowpack, in many instances less than 25 percent of normal, was observed in the southern Cascades, Sierra Nevada Mountains, Great Basin and Southern Rockies. Above-average snowpack was observed in the northern Cascades and Northern Rockies with totals more than 180 percent of normal in parts of Wyoming and Montana. Near- to below-average snowpack was observed in the Central Rockies. In Alaska, below-average snowpack was observed across southern parts of the state with much-above-average snowpack for interior locations.


Significant Events

Savannah Snow
4 Jan Satellite View of Savannah, GA snow
Source: NASA

During the month, several large winter storms impacted the eastern United States bringing snow to every state east of the Rockies. Some locations in the South saw the largest snowfall totals in nearly three decades. The most potent of the events impacted the East on January 3rd through 5th. A low pressure system moved across the South and then up the East Coast. Snow fell as far south as Tallahassee, Florida. Savannah, Georgia received 1.2 inches of snow, the most since December 1989. Snowfall totals were much greater across the Northeast with well over one foot of snow in parts of New England. Another winter storm moved through parts of the South into the Northeast on January 12th and 13th, bringing over 6 inches of snow, in addition to ice, across the Ohio Valley into the Northeast. In the South, sleet and freezing rain impacted Arkansas, Mississippi and Tennessee. The last big storm to impact the South hit on the 17th and 18th with heavy snow stretching from Louisiana to New England. Over 3 inches of snow, which is unusual but not unprecedented, was observed in parts of northern Louisiana, Alabama, Mississippi and Georgia with over six inches of snow in parts of Arkansas, Tennessee and Kentucky. Snow totals exceeding one foot were observed from central North Carolina and Virginia, stretching into the Northeast.


Citing This Report

NOAA National Centers for Environmental Information, Monthly National Snow and Ice Report for January 2018, published online February 2018, retrieved on March 2, 2024 from https://www.ncei.noaa.gov/access/monitoring/monthly-report/snow/201801.