Current Conditions at Sanborn Field

Wednesday Night: Overcast with showers in the late evening. Low: 50

 

 

Thursday: Sunny sky. High: 56

 

Thursday Night:  Clear. Low: 38    

Friday:  Mostly cloudy. High: 43

 

Friday Night: Partly cloudy. Low: 28

 

 

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Discussion: 

    In typical Missouri fashion, the past few days of warm, pleasant weather give way to wet and cold conditions as we finish out the week. Wednesday night will see the beginning of those declining conditions as a low pressure system to our northwest brings showers to Columbia. As this low transitions to our northeast, winds will shift to the north bringing in cooler air for Thursday and Friday. Thursday sees a shift toward a clearer sky as conditions calm, leaving only clouds and cool temperatures for the remainder of the week. A chilly Friday night caps off our week with lows in the upper 20s. Total rainfall amounts are anticipated to be about 0.5" for the forecast period.

 - Noblitt

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Forecasters: McMullen, Noblitt, Cochran

Date Issued: 11/10/21 5:00 PM CST

Technical discussion:  

    This forecast was made using the 12Z run of the NAM40. The NAM40 and the GFS20 plots of MSLP were very similar when compared to the current surface map. The NAM40, however, was more accurate with it's prediction of the current surface temperatures. NAM40 soundings were used in forecasting cloud cover and SREF plumes were referenced for temperatures and precipitation. A LPS system and its associated trough will be the main influence of our weather for the remainder of the week.

    An upper-level trough will dominate the weather in our area for the rest of the week. When looking at the 250-mb plot of heights, winds, and divergence, a significant upper level trough is located to our west over the Plains region. This trough will begin to move into Missouri around 0Z Thursday bringing with it some upper-level divergence that promotes cloud development throughout the night. A low located in the Northern Plains will begin to shift southward through Friday at 0Z, moving across southern Minnesota and eventually traveling NE through the rest of the forecast period. The positively-tilted trough will exit our region at about 12Z Saturday. The jet stream stays to our south during the forecast period, influencing our area very little. 

    Using the 500-mb plot of heights, winds, and vorticity, two separate bands of circulation pass through Central Missouri during the rest of the week. The first band of circulation, associated with the previously mentioned trough, pushes through the Mississippi Valley from 6Z Thursday through 18Z Thursday. This circulation will aid in cloud development over our region. The second band of circulation, affiliated with the aforementioned LPS over the Northern Plains, begins to move into Missouri at 18Z Thursday remaining strong until 3Z Friday.  Weak circulation remains over our area until 7Z Saturday as the LPS passes eastward. 

    A large swathe of moisture, seen on the 700-mb plot of heights, winds, and RH, migrates through Mid-Missouri from 0Z to 12Z Thursday. This moisture, brought in by the LPS, keeps our atmosphere saturated and aids in rainfall for this time period. A second, more moderate area of moisture travels through our area beginning around 12Z Friday and leaving us at approximately 1Z Saturday. This second area is also brought in by the LPS to our northeast which assists in cloud production over Columbia. 

     As seen on the 850-mb plot of heights, winds, and temperature, there will be a shift in our winds caused by the LPS to our north. Southerly winds, which previous brought us warmer temperatures, will begin to shift to the northwest beginning 9Z Thursday. These winds will eventually shift to the west at 21Z Thursday, caused by the passage of the LPS over Minnesota. As the LPS travels NE, cooler air brought by northerly winds blows into our region for the rest of the forecast period. Looking at the 1000MB-500MB Thickness and MLSP plot, strong solenoids are present from 10Z to 21Z Thursday. These solenoids, alongside northwesterly winds, show CAA occurring in our region.

    NAM40 soundings indicate showers, but no severe storms are expected as shown by the insignificant LI values and high K-Index values for Wednesday night. Total QPF values show 0.5" of precipitation expected through the forecast period, mostly occurring overnight Wednesday. 

    Future forecasters should keep an eye out for some incoming moisture from our northwest over the weekend. Discretion is advised with temperature forecasting for Thursday as models are not in consensus.

- McMullen