November 2018 Climate and Hydrology Summary

Tulsa: November 2018 was the 13th coldest (45.4°F; since 1905), the 51st driest (1.67"; since 1888), and the 13th snowiest (1.6"; since 1900) November on record.

Fort Smith: November 2018 was the 11th coldest (46.5°F; since 1882) and the 40th driest (1.67"; since 1882) November on record.

Fayetteville: November 2018 was the 2nd coldest (41.3°F, tied 2000, 1972; since 1949), the 33rd driest (2.72"; since 1949), and the 12th snowiest (0.3", tied 1991; since 1949) November on record.

McAlester: Daily records set or tied this month include a record cold minimum temperature.

Using the radar-derived estimated observed precipitation from the RFCs, rainfall totals for November 2018 ranged from 0.50” to near 5” across eastern OK and northwest AR. This corresponds to 10% to 75% of the normal November rainfall across the majority of the area. Only a small portion of Benton County AR received 75%-110% of the normal rainfall this month.

It was a fairly quiet November across eastern OK and northwest AR, though there was minor river flooding (from late Oct. rainfall) at the beginning, snow in the middle, and tornadoes at the end of the month. Temperatures were generally cold this month, with most locations 5˚-6˚F below normal.

Minor flooding occurred along the Poteau River near Panama due to rain at the end of October.

According to the U.S. Drought Monitor from November 27, 2018, Moderate (D1) drought conditions were present across portions of Pawnee, Osage, Washington, Rogers, Mayes, Delaware, and Cherokee Counties in eastern OK, and Benton County in northwest AR. Abnormally Dry (D0) but not in drought conditions encompassed portions of Pawnee, Osage, Creek, Washington, Tulsa, Rogers, Mayes, Nowata, Craig, Ottawa, Delaware, Okfuskee, Okmulgee, McIntosh, Wagoner, Muskogee, Cherokee, Sequoyah, and Adair Counties in eastern Oklahoma and Benton, Carroll, Washington, Madison, Crawford, and Franklin Counties in northwest Arkansas.

According to the Oklahoma Climatological Survey (mesonet stations only), November 2018 was the 31st driest for northeast Oklahoma, the 28th driest for east central Oklahoma, and the 40th driest for southeast Oklahoma. Records go back to 1921. For Fall 2018 (September 1 - November 30), northeast Oklahoma ranked as the 41st driest, east central Oklahoma was the 47th wettest, and southeast Oklahoma was the 13th wettest period. For Year-to-Date 2018 (January 1-November 30), northeast Oklahoma ranked as the 30th driest, east central Oklahoma was the 20th wettest, and southeast Oklahoma was the 12th wettest Year-to-Date.

Showers and thunderstorms increased across eastern OK and western AR mid-morning on October 31st as an upper-level trough approached the region. The system was slow to clear the area, resulting in lingering rainfall and soggy trick-or-treating across southeast OK and west central AR during the evening hours. Rainfall totals ranged from 1”-3” southeast of a McAlester to Springdale line. This rain also resulted in minor flooding along the Poteau River near Panama (see E3 Report for details).

A low pressure system moved into the region on the 12th, and strong frontogenetic forcing produced bands of snow across northeast OK and northwest AR. A large portion of northeast OK and northwest AR received 0.5”-2” of snow, with isolated totals of 2”-3”. Further south, the precipitation remained liquid. Rain and snow liquid equivalent totals were around 0.25” or less. The next morning, the snow on the ground was still visible on satellite.

There were two rounds of thunderstorms during the evening of the 30th. A warm front across southeast OK early on the 30th lifted north through the day, with storms developing in the warm sector across eastern OK and western AR during the early evening hours. These storms moved northeast and exited the region by mid-evening. A second area of showers and thunderstorms developed in association with an upper trough moving into the region. This line of storms formed across central OK and north central TX and moved into eastern OK during by mid-evening and into western AR by late evening. These storms were strong to severe, with additional severe storms developing ahead of the line. These storms produced damaging winds and several tornadoes. Information about the tornadoes can be found at https://arcg.is/1f5Ob4. All of this activity quickly came to an end by 2 am CST on 1st as the system moved east of the area. Rainfall from this event ranged from around 0.25” to around 2.5”.

Autumn (September-October-November) 2018

Tulsa: Autumn 2018 was the 27th coldest (60.9°F; since 1905) and the 46th driest (7.82"; since 1888) Autumn on record.

Fort Smith: Autumn 2018 was the 60th coldest (62.4°F, tied 1988, 1896; since 1882) and the 25th wettest (14.12"; since 1882) Autumn on record.

Fayetteville: Autumn 2018 was the 17th coldest (57.4°F, tied 2009, 2000, 1972, 1949; since 1949) and the 20th driest (8.02", tied 1995; since 1949) Autumn on record.

Severe Thunderstorms in Northwest Texas; Dry Conditions and Gusty Winds Across Colorado