Wednesday, March 8, 2023


Wednesday Night:
Overcast. Low: 39

Rain. High: 43


Thursday Night:
Rain. Low: 34

Mostly cloudy. High: 47

Friday Night: Mostly Cloudy. Low: 32


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Rain is on the way Thursday, brought to you by a low pressure system that will be moving directly over Missouri Thursday evening. Moisture will be abundant at multiple levels of the atmosphere for much of the forecast period, leading to a lot of cloud cover, and the aforementioned rain event. Overall, things will be cold, wet, and dreary.  



Forecasters: Chirpich, Cook, Travis

Date Issued: 03/08/2023 5:00 PM CST

Technical Discussion:

After a warm up this past weekend, we are back to seasonal conditions for the end of this workweek into the start of this weekend. The main focus of this forecast shift will be the passage of a low pressure system over the CWA Thursday evening. This system will be bringing with it precipitation for the whole Missouri region. For this forecast, the GFS models and model soundings were used for the formulation of this forecast. 

At 300mb, the CWA is under the influence of a ridge for Wednesday night into Thursday morning. Around midday on Thursday, the ridge will be forced off to the east by a small trough. This trough is associated with the surface low that will be pushing through the region Thursday evening, bringing with it some measurable precipitation. Missouri will be under the influence of this trough through Friday morning. This will be followed by another ridge, which will sit over the CWA until the end of the forecasting period, leading to zonal flow in the upper levels of the atmosphere.

At 500mb, the first sign of vorticity signatures over the CWA comes around midday. These signatures are out ahead of the center of the low, and indicate the presence of lift out ahead of the low. The low will move through Missouri and off to the northeast by early Friday morning. After that, zonal flow is modeled with no vorticity signatures around the CWA till the end of the forecast period. Model soundings show saturation in the upper levels of the atmosphere from Wednesday night until Thursday evening, and then again around noon on Friday until the end of the forecast period. This suggests the presence of upper level clouds during these times. This helps support the overcast/mostly cloudy conditions that are forecast for the forecast period. 

At 700mb, moisture is going to be moving in overhead early Thursday morning. This moisture is followed by vertical velocity signatures. These signatures are positioned out ahead of the center of the low pressure system. With the presence of moisture and lift, mid-level clouds are likely for Thursday afternoon into Thursday evening. Model soundings suggest that the moisture will extend all the way to the surface from midday Thursday into Thursday evening. This suggests precipitation during this time. Because of the temperatures at and near the surface will be above freezing, the precipitation type will be rain. The moisture will clear out of the area late Thursday night, leading to a calm pattern. Moisture will return to the region early Saturday morning, and persist past the end of the forecast period.

At 850mb, there is moisture present from the beginning of the forecast period up until early Friday morning. Before the precipitation event Thursday afternoon, there will be overcast conditions caused by the presence of lower level clouds. Model soundings show the cloud layer to be quite thick, supporting overcast conditions. The moisture will leave the region Friday morning, followed by drier air. Moisture will build to the west of the CWA, and looks to move in shortly after the end of the forecasting shift on Saturday. 

At the surface, the center of the low pressure system will pass right over the CWA as it traverses east-northeast through mid Missouri Thursday evening. Because of the low being centered right on top of the CWA, the measurable precipitation values look to be lower than the southern and northern parts of Missouri. In Columbia, the expected amount of liquid precipitation is anywhere from 0.15in to 0.25in of rain in total, with the majority of it falling during the afternoon on Thursday.


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