Current Conditions at Sanborn Field

Monday: Becoming partly cloudy. High: 68

Monday Night: Cloudy Low: 52

Tuesday: Cloudy with rain. High: 54

Tuesday Night: Cloudy. Low: 16

Wednesday: Cloudy with possibility of flurries. High: 26

 

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Discussion:

 If you didn't get a chance to enjoy the warmer weather yesterday, today will be the last day of milder temperatures before we dip back into the cold. Today, Mid-Missouri will see an increase in clouds as the day progresses due to a stalled cold front to our north, in Iowa. This front will push through around mid-day tomorrow due to a low pressure system to our west in the Rockies. Our high temperatures will be seen on Tuesday morning before the front pushes through, meaning temperatures will continue to fall throughout the day. As temperatures dip back below average for Tuesday and Wednesday, another chance for precipitation comes our way as the low pressure system progresses eastward into the Midwest. The best chance to see precipitation will be Wednesday afternoon with trace amounts before heading into the evening commute hours. 

-Gromada

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Forecasters: Baker, Bongard, Gromada

Date Issued: 2/21/2022 10:00AM CST

Technical Discussion: 

 

The GFS20 model run was used for this forecast as it handled the fluctuating temperatures and the passage of the cold front Tuesday better than other models. The problem of the day consists of uncertainty of when the cold front will move through Tuesday altering the high and low temperatures. 

 

Southerly winds throughout Sunday night will give way to an above average temperature day Monday as the Low Level Jet brings in warmer temperatures and moisture. Wind gusts as high as 20 kts out of the south will allow for temperature and moisture advection into the area. 

 

Split flow is evident Monday morning as there is a large gap between the polar and subtropic jet stream across the middle of the CONUS. Zonal flow is quickly pushed east Monday afternoon as an amplified trough to the Northwest sets up into the Central Plains. As the trough pushes across the Rockies, values of divergence are seen at 06z Tuesday as a jet streak moves over mid-Missouri. 

 

High level winds are seen through each layer of the atmosphere as winds between the surface all the way up to 850mb are straight out of the south. While, winds between 850-500mb are more westerly. This profile gives way to moisture and temperature advection at 850 mb. With differing winds in the upper levels, wind shear is evident. 

 

The concentration of this forecast is focused on the low pressure system that tracks from the Rockies that currently situated in northern Kansas. A cold front is draped across southern Iowa into Illinois. This cold front is battling the southern flow throughout the day Monday into Tuesday, which makes the timing of the frontal passage uncertain Tuesday afternoon. 

 

As we warm up today, instability is going to increase as we see values of vorticity move their way into the area late Monday into Tuesday. These values support the chance of overcast and rainy conditions Tuesday morning into the afternoon ahead of the cold front. Tight solenoids are seen on the 1000-500mb thickness map evident of warm air advection in contribution with the LLJ.

 

Relative humidity values begin to increase Monday as the LLJ brings in upper level clouds. Values continue to increase as more moisture is brought into the area. As the low pressure system moves its way across the Iowa/Missouri boarder into Illinois, rain ahead of the front will begin to effect the area early Tuesday. Rain will be heavy at times, and the possibility of a few rumbles of thunder should not be ruled out. After this pocket of moisture dries out and moves east, the mid-Missouri area will see precipitation again Wednesday at 21Z.

Winds resume out of the north after the frontal passage moves east Tuesday afternoon allowing for the cold temperatures to build in dropping into the teens Tuesday night. The 5400 Thickness contour moves across the mid-Missouri area Tuesday night, allowing for cold air advection to take over, leading to a transition period on Wednesday. Overcast conditions will persist, and chances for precipitation Wednesday afternoon into the evening is possible; however, a light dusting of snow is possible.

 

The SREF and GREF plumes had quite a large spread for temperatures; therefore, soundings and the National Blend of Models plots were used for temperature guidance.

 

-Baker