LIMA, OH (WLIO) - November was bookended by mild weather with very cold weather during the middle of the month. Temperatures as a whole ended up slightly warmer than normal, and precipitation was much below normal. The dryness carried over from a very dry October, resulting in moderate drought conditions.
What can we expect in December? Before we get into the nuts and bolts of the forecast, let's take a look at climate normals for the month. The average high goes down from 44° to 35° during the month, and nighttime lows typically range in the 20s. Snowfall averages around 6" for the entire month. Remember, climate tells us what weather we "expect", but weather is what you get! Our weather often strays far from the "average."
This data above is based off our observed weather from 1991-2020. However, there have been eye-catching trends the last several years. Our seasons are delaying a bit, with Decembers trending milder and less snowy over the last decade. On the other hand, Februarys are trending snowier while the average temperature hasn't budged. Bottom-line, the harsher weather has been trending to occur later vs. earlier over the last several winter seasons. In fact, 75% of the last 11 Decembers have been warmer than normal. December 2021 was our second warmest on record, with 2015 in first place.
Could this year buck that trend? While forecasting beyond a week is always challenging, the signals are growing for a December that ends up with below normal temperatures this year. Very strong blocking is forecast to develop over Greenland in the coming days, and eventually retrograde west with time. This will help force the colder weather and the jet stream south from Canada into the lower 48. Forecast data continues to build a colder pattern into the United States heading into mid-month.
The current forecast from NOAA's Climate Prediction Center is on board with colder than normal weather favored across our area. Those cold probabilities are highest over the northern Plains and upper Midwest. Precipitation is much less certain, with drier weather favored in northern Indiana and southern Michigan, with wetter conditions in Kentucky and southern Ohio.
It should be noted - colder temperatures don't automatically equate to more snow. In fact, we could see less precipitation at times as the jet stream gets shoved south of here. However, the systems we do get have a better chance to tap into cold air to produce snow or a mix. The favorable snow chances will take some time to set-up shop, but it looks like better opportunities develop toward the middle of the month. While we cannot accurately say how much snow, odds favor getting some snow down at some point prior to Christmas this year.
