Current Conditions at Sanborn Field

Tuesday Night: Overcast. Rain, isolated thunderstorms early evening. Low: 42

Wednesday: Cloudy with rain. High: 43

Wednesday Night: Cloudy with intermittent showers. Low: 38

Thursday: Overcast and rainy High: 44

Thursday Night: Sky clearing. Low: 37

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Discussion: 

This week is trying its best to be cold and rainy; what a way to start off spring! Tonight will have showers and a chance of isolated thunderstorms starting early in the evening continuing to around midnight. After midnight, the likelihood of thunderstorms diminish, but rain will continue. As the sun begins to rise Wednesday morning, a cold front will sweep through the area causing a quick wind shift to the northwest and temperatures to drop throughout the day. Rain is expected to continue throughout Wednesday and until Thursday morning when the low pressure system causing this rain will begin heading east, taking the moisture with it. Columbia can expect to pickup around .45 inch of rain by midday Thursday. We should be able to see some stars Thursday night as the clouds begin clearing out. 

-Alexander

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Forecasters: Alexander, Duff, Orr

Date Issued: 3/22/2022 05:00PM CDT

Technical Discussion: 

   
The problem during this forecast period is dreary conditions with an overcast sky and persistent rain for the next few days. There is also a chance for some isolated thunderstorm activity early in the forecast period. The 12Z model run of the GFS was used in the making of this forecast. It outperformed the NAM and other models in the forecasting of surface temperatures while there was not a significant difference in the placement of any of the current atmospheric features. Finally, the NBM and GEFS plumes were used to predict rainfall totals for the period.

In in the upper atmosphere, a deep trough sits to the west of Missouri over the Great Plains, extending into northern Mexico. A jet streak at 250mb wraps around the base of the trough with the strongest jet max centered over central Kansas and western Missouri. As the trough moves east, Mid-Missouri sits in the right entrance region of the jet streak indicating divergence aloft. Overnight on Wednesday, the trough becomes positively tilted over Missouri and a strong jet streak develops to the southeast, placing Missouri in the left exit region of the trough for most of Wednesday.


At 500mb strong circulation wraps around the low pressure system and move east towards Missouri. The strongest vorticity passes over Columbia late on Tuesday and early Wednesday, which will help in the development of rain and the potential for thunderstorms during this time. Increased vorticity continues over Mid-Missouri through the end of the forecast period.


Similarly, decreasing values of omega at 700mb are present during the forecast period with the lowest values around 00Z and 03Z Wednesday. Values of relative humidity at 700mb stay fairly high throughout the forecast period. There is an increase during the day on Wednesday as moisture wraps around the low pressure system. The presence of deep moisture and significant lift will help in the development of any thunderstorm activity early Tuesday evening and help with the persistent rain on Wednesday and Thursday. Soundings during this time are also evident of saturation going down to the surface and very low values of omega.


At 850-mb, high values of relative humidity are forecasted starting late on Tuesday as moisture is wrapped around the low pressure system. Winds have been out of the south for the past few days, which helps the low level jet to advect moisture into the region. During the forecast period the low pressure center moves closer to the CWA and moisture is then wrapped around the cyclone and pools over Missouri. The wind shifts to a northerly direction early morning Wednesday after the passage of a cold front and then becomes more westerly as the system moves off to the east.


As mentioned earlier, one of the problems during this forecast is the potential for convection early on Tuesday night. It is evident that there will be significant forcing and moisture Tuesday evening around 03Z Wednesday. So, this is likely when precipitation will begin for Mid-Missouri and, during this time, there is also the possibility for isolated thunderstorms. GFS soundings show that the highest amount of MU CAPE is around 174 J/KG, indicating that the potential for severe thunderstorms is unlikely, but a few rumbles of thunder are possible during this time.


Temperatures are expected to be much cooler for the end of the forecast period because of rainy and overcast conditions during the day and the passage of the cold front around 12Z Wednesday. Rain is expected to start Tuesday evening with a total accumulation of less than a quarter of an inch. During the day on Wednesday accumulations are expected to be less than .15 of an inch, less than a tenth of an inch Wednesday night, and trace amounts on Thursday. Total rain accumulations are expected to be around half an inch. Future forecasters should monitor cooler temperatures and wet conditions.


-Duff