Friday: Mostly cloudy, breezy. High: 43
Friday Night: Partly cloudy. Low: 28
Saturday: Increasing clouds through the day. High: 43
Saturday Night: Overcast. Low: 40
Sunday: Decreasing Clouds. High: 47
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This weekend will be a period of well below average temperatures for the Mid-Missouri area. Temperatures are expected to steadily fall throughout the day Friday thanks to northerly winds as low pressure exits our region. This will also bring blustery conditions to the area today with wind gusts up to 25 mph in the afternoon. Marginal cloud cover persists all day and lasts through much of Friday night. A frosty Saturday morning is in store with clearer skies and temperatures dipping below freezing. Gameday will see much of the same conditions as today with highs nearly 10 degrees below average but expect a bit more sunshine during the day. Overcast skies return Saturday night, though, ahead of our next chance for rain. A cold front will sweep across the region early Sunday morning and bring showers and potentially a few flakes to the area. No impacts will be expected with very little, if any, winter precipitation possible. Rainfall amounts will reach up to 0.1". Rain clears up early for a cloudy and chilly end to the weekend.
Forecasters: Schneringer, Splater, Bongard
Date Issued: 11/12/21 10:00 AM CST
Technical discussion: Progression of a strong upper level low over Wisconsin and the development of another trough in the upper levels later on in the weekend are going to be the highlights for the weather this forecast. The 12Z run of both the NAM and GFS were consulted to determine placement of moisture Saturday night/Sunday morning, and both models displayed consensus with the placement and progression of the upper level low. However, the 12Z GFS run was primarily utilized for this forecast, along with generated soundings and cross-sections, due to its better handling of morning temperatures for the Columbia region.
The upper level low centered over northern Wisconsin today will progress to the northeast into Ontario, and towards Quebec and the Hudson Bay by late tonight. A strong trough pattern is present over Missouri due to this, and vorticity and strong RH values will lead to cloudiness today, especially early-mid afternoon. A lack of forcing precludes any precipitation from these conditions however. Strong northerly/northwesterly flow at all levels will be a trend today and the rest of the weekend, contributing to significantly below-average high and low temperatures.
As the backside of the trough passes over the region Saturday, a moderate jet will develop overhead. The trough will quickly exit the region, and flow aloft will transition into a more zonal pattern throughout the day and into early evening. The upper levels will dry out as the moisture is pulled out of the area by the exiting low, leading to a more sunny day, but not any warmer due to the continued presence of northwesterly flow and CAA. As Saturday evening progresses, moisture will return to the area as a shortwave approaches the region.
Late Saturday night/early Sunday morning will see chances for showers due to the shortwave rippling through the upper levels. At the 250-mb level, a shallow trough that began to develop over southern Saskatchewan/Manitoba Saturday afternoon will rapidly dive southwards into the Great Plains, with the axis sitting squarely over mid-Missouri. The nose of a powerful jet core will enter the forecast region on the backside of this trough, with associated divergence aloft along with it. Due to these factors, the development of moisture over the forecast region between 06-09Z will determine the extent of showers that occur. The Columbia region sits on the southern extent of the modeled moisture plume according to the GFS, with the NAM being a little more bullish on RH values in that time frame. How these models will progress this factor in the next few runs will determine the extent of precipitation early Sunday morning. At this time, the forecast rainfall accumulation does not exceed 0.1". The atmosphere will dry out over the forecast area following the passage of a front in the morning. Clear skies and a shift to more westerly flow will contribute to a slightly warmer day Sunday.-Schneringer