Winter in Oklahoma

The days are shorter, the winds are stronger, and the nights are colder – winter is arriving in Oklahoma. Winter brings to mind thoughts of heavy coats, blustery days, and snow, but what kind of weather can we actually expect to see in the months ahead? How will winter of 2008 compare to an average Oklahoma winter? Just what is an average Oklahoma winter? Get ready to tackle some climatology, because we’re about to find out.

We’ll begin by taking a look at what a “typical” winter looks like here in Oklahoma. As with many continental northern hemisphere sites, January is, statistically speaking, the coldest month of the year, followed by December and February. Together these three months make up the “meteorological winter” commonly used in scholarly articles, often in the form of “DJF” plots of winter-averaged variables. In mid-January, temperatures dip to their coldest, with an average high of just 46°F and an average low of 26°F, as seen in the plot of yearly average temperatures above – the average high and low are denoted by the top and bottom of the green band in the upper panel. The range of possible temperatures varies widely during an Oklahoma winter – readings below zero have been reported between mid-December and mid-February, but temperatures in the 70’s and very rarely even the low 80’s are not uncommon even in mid-winter.

Despite enjoying a relatively mild climate, frozen precipitation is common during an average Oklahoma winter. Oklahoma City receives, on average, about 9 inches of snow per year, with January being the snowiest month. Ice storms are not uncommon either—one notable recent ice storm blanketed much of Oklahoma with ice during the night of December 9, 2007, leaving upwards of an inch of ice glaze in some areas, toppling trees and knocking out power to over a million customers.

Variability is a key feature of Oklahoma winters, one that this article would not be complete without addressing. During the winter, weather over much of the Southern Great Plains is dominated by synoptic-scale features, perhaps the most noticeable of which are the cold fronts that periodically rush through, bringing northerly winds and cold, dry Canadian air. In between these cold surges, warm air and gulf moisture often have a chance to return via southerly winds, bringing almost springlike conditions. The change between these two states can often be abrupt, as seen on November 11, 1911, when Oklahoma city set a record high (83°F) and a record low (17°F) on the same day.

How will the winter of 2008 compare? If climatological forecasts verify, we can expect a good chance of a warm, wet winter – the Climate Prediction Center (CPC) predicts a 50% chance of above normal temperatures during December, January, and February of 2008-2009, and only a 20% chance of below-normal temperatures during the same time period. The CPC also predicts a 40% chance of above-normal precipitation during this winter (in an “average” year, the chance would be 33%).





Story is © Nate Snook, 2008