January 2018 Climate and Hydrology Summary

January 2018

Tulsa: January 2018 was the 56th warmest (37.5°F, tied 1981; since 1905), the 11th driest (0.26"; since 1888), and the 12th least snowy (Trace, tied 18 other years; since 1900) January on record.

Fort Smith: January 2018 was the 46th coldest (38.1°F, tied 1983; since 1883), the 65th wettest (2.23", 1966; since 1883), and the 29th least snowy (Trace, tied 18 other years; since 1884) January on record.

Fayetteville: January 2018 was the 19th coldest (33.8°F; since 1950), the 27th driest (1.71"; since 1950), and the 10th least snowy (Trace, tied 16 other years; since 1950) January on record.

Fayetteville: Daily records set or tied this month include a daily rainfall record.

Using the radar-derived estimated observed precipitation from the RFCs, rainfall totals for January 2018 ranged from around 0.10” to near 3” from northwest to southeast across most of eastern OK and northwest AR. A narrow swath of higher rainfall, around 3” to around 5”, occurred across far southeast OK into west central AR. This corresponds to less than 5% to 90% of the normal January rainfall for most of the area northwest to southeast across eastern OK and northwest AR. Isolated portions of southeast OK and west central AR had 90% to around 150% of the normal January rainfall.

Most of the region had below normal rainfall to start 2018, with the greatest deficits across northeast OK. Only a small portion of southeast OK had above normal rainfall. Temperatures were near to below normal this month as well.

2018 started off very cold, as an arctic anticyclone brought below freezing temperatures to eastern OK and northwest AR for several days - northeast Oklahoma went just over 100 hours with below freezing temperatures. Most locations had temperatures drop into the single digits during this time. Temperatures rose back above freezing on January 3rd.

A cold front moved into the area on January 15th, bringing snow during the morning and afternoon to far northeast OK and along the AR/MO state line. Snowfall totals ranged from 0.5” to around 3”. Liquid equivalent amounts ranged from a few hundredths to near 0.25”.

A vigorous and progressive short-wave trough moved into the Plains on January 21st, helping to spawn showers and thunderstorms ahead of a cold front during the afternoon and evening hours. This activity affected locations along and southeast of a Stidham to Miami line, bringing 0.25” to 2” of rain to much of southeast and east central OK and northwest and west central AR. Training of storms resulted in isolated areas of 2”-2.5” and a swatch of 2”-4” in eastern Pushmataha and southern Le Flore Counties. Due to the antecedent drought, no flooding occurred. Two EF-1 tornadoes occurred in west central AR with this storm system.

According to the Drought Monitor from January 30, 2018, Severe Drought (D2) impacted parts of Osage, Pawnee, Washington, Creek, Okfuskee, Okmulgee, McIntosh, Pittsburg, Latimer, Haskell, Le Flore, Sequoyah, Muskogee, Wagoner, Mayes, Cherokee, and Adair Counties in eastern OK and Washington, Madison, Crawford, Sebastian, and Franklin Counties in northwest AR. Moderate (D1) drought conditions were present across portions of Osage, Washington, Nowata, Craig, Ottawa, Delaware, Mayes, Rogers, Tulsa, Creek, Wagoner, Adair, Le Flore, Pushmataha, and Choctaw Counties in eastern OK and Benton, Carroll, Madison, and Washington Counties in northwest AR.

According to the Oklahoma Climatological Survey, January 2018 was the 9th driest for northeast Oklahoma, the 25th driest for east central Oklahoma, and the 42nd driest for southeast Oklahoma. Records go back to 1921. For Winter-to-Date (December 1, 2017-January 31, 2018), northeast Oklahoma ranked as the 3rd driest, east central Oklahoma was the 20th driest, and southeast Oklahoma was the 46th driest. For the Water Year-to-date, October 1, 2017-January 31, 2018, northeast Oklahoma ranked as the 33rd driest, east central Oklahoma was the 21st driest, and southeast Oklahoma was the 25th driest period.