The US National Oceanic and Atmospheric Administration (NOAA) National Climatic Data Center (NCDC) has released their latest State of the Climate, “a collection of monthly summaries recapping climate-related occurrences on both a global and national scale.”
The title for the January 2013 summary reads “Contiugous US warmer and wetter than average for January”, noting that “Drought persists for central US” and “above-average January snow cover extent for Lower 48”.
The report notes that average temperatures for the contiguous US during January was 0°C (32.0°F), 0.8°C (1.6°F) above the 20th century average, tying with 1958 as the 39th warmest January on record.
Precipitation data showed that the January nationally-averaged total was 2.36 inches, 0.14 inches above the long-term average. However the average masked both wet and dry extremes across the country, specifically drought conditions which remained entrenched across the Southeast, Great Plains, and the mountainous West.
Below are a selection of highlights from the January State of the Climate;
U.S. climate highlights: January
- January brought warmer-than-average conditions to the eastern half of the contiguous United States, despite several cold air outbreaks. The largest warm temperature departures from average were in the Southeast, whereGeorgia and Florida both had their 11th warmest January with monthly temperatures 5.7°F and 5.6°F above average, respectively.
- Below-average temperatures were anchored in the western United States. Nevada had its ninth coolest January on record with a monthly temperature 5.9°F below average andUtah had its eighth coolest January with temperatures 7.5°F below average.
- Wetter-than-average conditions stretched from the Southern Plains to the Mid-Atlantic, where Louisiana,Mississippi, Tennessee, Michigan, and Virginia each had January precipitation totals ranking among their ten wettest. The above-average precipitation generally missed the core drought areas of the central and southeastern United States.
- Drier-than-average conditions were observed along the West Coast, the central Rockies, and parts of the Northern Plains, Southeast, and Northeast. California, Connecticut, and Florida each had one of their ten driest January.
- According to data from the Rutgers Global Snow Lab, the January snow cover extent for the contiguous U.S. was above average at 1.4 million square miles. Mountain snowpack was near-average for much on the West, with the exceptions of the Northwest where snowpack was much above average, and the Central and Southern Rockies where snowpack was much below average.
- Alaska was warmer and wetter than average. The statewide average temperature was 7.1°F above average and the precipitation total was 64 percent above average. Parts of the state had monthly temperatures more than 10°F above normal.
- According to the January 29 U.S. Drought Monitor report, 57.7 percent of the contiguous U.S. was experiencing moderate-to-exceptional drought, smaller than the 61.1 percent at the beginning of the month. Drought conditions improved in parts of the Mid-Atlantic and Mid-Mississippi River Valley.
U.S. climate highlights: Winter-to-Date (December 2012 — January 2013)
- The first two months of the winter season, December and January, were warmer than average for the contiguous United States and ranked as the 18th warmest such period on record. The two-month period had an average temperature 2.5°F above average. Much of the warmth occurred across the eastern half of the nation. The West Coast and Southwest were slightly cooler than average during the 2-month period.
- An active storm pattern in the eastern U.S. resulted inwetter-than-average conditions during the first two months of winter. Louisiana, Mississippi, Michigan, andPennsylvania each had a top ten wet period. The nationally-averaged precipitation total for the two-month period was 5.10 inches, 0.65 inch above average.
U.S. climate highlights: Last 12 months (February 2012 — January 2013)
- The 12-month period, ending in January, was the warmest such period for the contiguous U.S., with every state being warmer than average. Sixteen states, across the central U.S. and Northeast, were record warm, and 27 additional states were top ten warm. The February-January nationally-averaged temperature of 55.0°F was 2.9°F above average and the ninth warmest of any 12-month period on record for the nation.
- The nationally-averaged precipitation total of 26.95 inches for the February-January period was 2.19 inches below average. Much of the central U.S. was drier than average. , Colorado, and Missouri had a top ten dry 12-month period, while Colorado and Nebraska were record dry. Wetter-than-average conditions occurred in the Pacific Northwest and central Gulf Coast where Washington and Louisiana had a top ten wet period.