Wednesday, February 23, 2022

 

Current Conditions at Sanborn Field

 



Wednesday:
Overcast. High: 25

 


Wednesday Night:
Cloudy. Low
: 22



Thursday:
Wintry mix then snow. High: 28

 


Thursday Night:
Snow ending before midnight. Cloudy. Low: 17

 


Friday
: Clear. High: 30


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Discussion:
 
Are you beginning to wonder if mid-Missouri weather has something against Thursdays? We are too! In addition to bitterly cold temperatures, a wintry mix of sleet and snow is expected to begin on Thursday morning before transitioning into snow exclusively by early afternoon. Snowfall will come to an end by the late evening hours on Thursday with accumulations between 1 and 3 inches. Cloud cover will decrease as we move into early Friday morning, bringing us some much needed sunshine and warmer temperatures as we head into the weekend.

- Macko

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Forecasters: Kobielusz, Macko, Bongard

Date Issued: 2/23/2022 10:00AM CST


Technical Discussion: 

    The 06Z run of the NAM40 was chosen for this forecast. After examining both the NAM40 and GFS20, we concluded that both models were running warm; however, the NAM40 was better depicting low pressure over the four corners region and a high over the Dakotas. The placement of the low over the four corners is important because this low will be associated with the snowfall that we are expecting and the track of the low will be a factor in how much snow will accumulate, which is the biggest challenge of this forecast. Soundings and the National Blend of Models were consulted for forecasting p-type and timing of precipitation. In preparation for upcoming winter precipitation, the National Weather Service has issued a Winter Weather Advisory beginning at noon today.

A deep, positively tilted trough is located over the central Great Basin region. This trough will push east into mid-Missouri over the forecast period. Currently Missouri is under the influence of an upper-level jet streak making our upper-level winds upwards of 150kts from the southwest. Just before noon today, an area of upper-level divergence encapsulates Missouri, implying the existence of lower-level convergence. This divergence clears out overnight only to reform during the evening on Thursday only not as strong. The jet streak however, strengthens over mid-Missouri with upper-level winds at 170kts out of the west.

Vorticity in the mid-levels is currently null. The first time Missouri will see vorticity in this forecasting period will be tonight over the I-44 corridor, but it will be weak. A noteworthy amount of vorticity associated will the positively tilted trough will move into mid-Missouri Thursday night.

There is a small area of upward vertical motion engulfed in a larger area of downward vertical motion currently over the forecast area. Throughout the day downward vertical motion will remain dominate before the trough moves into central Missouri late Thursday night bringing with it a large amount of upward vertical motion in the same area as the vorticity. This leads us to believe that there could be the chance for some precipitation, but moisture in the mid-levels in mid-Missouri will be scarce until late morning on Thursday. This is not the case in southern Missouri where moisture is abundant. This will pose the question of whether-or-not Columbia will be seeing snow on Wednesday.

A low-level jet streak just to our south will bring in low-level moisture from the Gulf of Mexico, but our low-level winds will remain out of the north causing our surface temperatures to be well below freezing and air, dry. Low-level moisture will increase on Wednesday and will remain throughout the day on Thursday before clearing out early Friday.

With the existence of the dry layer in the mid-levels Wednesday, any precipitation is going to struggle to reach the surface. Columbia may see a few stray snowflakes, but accumulation is not expected. By mid-morning on Thursday the dry layer should become more saturated and sleet is expected to reach the surface as a warm nose barely goes above freezing. Sleet is expected to transition into snow by early afternoon as the warm nose dips well below freezing. Accumulations for sleet are forecasted to be around 0.5" and total snow accumulations are expected to be within the 1-3" range.


-Kobielusz

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