Current Conditions at Sanborn Field 

 

 

Wednesday: Storms ending, rain continuing. Temperatures falling throughout the day. High: 58

 

Wednesday Night: Rain ending. Clearing. Low: 33

 

Thursday: Sunny. High: 60

 

Thursday Night: Clear. Low: 43

 

Friday: Clouds building in the afternoon. High: 65

 

 

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Discussion:

Who's playing weather roulette? The warm temperatures mid-Missouri has had over the last few days have taken their leave following the passage of a cold front on Wednesday morning. Rain associated with this frontal passage is expected to persist until Wednesday evening with the day's rainfall accumulations nearing 0.5". A slight warming trend and a clearer sky are to be anticipated later in the school week as high pressure builds into the region.

- Macko

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Forecasters: Kobielusz, Macko, Bongard

Date Issued: 04/13/2022 10:00AM CDT

Technical Discussion: 

Both the NAM and GFS were running warm; however, at the time of diagnostics the 06Z run of the NAM40 was placing a cold front closer to the observed location and had a better handle on the low-pressure system in Minnesota that is the source for the problem of the day. The problem of the day will be determining when the severe threat and rain will end, along with possible hazards and rainfall totals. The forecast period for this forecast will be from Wednesday morning to Friday evening. Soundings were used to aid in timing and the NBM was consulted for temperatures along with precipitation totals.

Currently in the upper levels of the atmosphere, there is a strong meridional flow. A deep, negatively tilted trough has its axis placed in western Nebraska and Kansas and an upper-level ridge is situated over the eastern CONUS. The upper-level low-pressure system associated with the aforementioned trough is currently in southern Montana. The jet stream is following this meridional pattern by flowing east-west from California to western Oklahoma before making a sharp turn to the north, making the jet stream south-north from Oklahoma through Minnesota and into Canada. Mid-Missouri is under the influence of this upper-level jet throughout the forecast period allowing for winds to come from the south; although, the flow becomes more zonal as upper-level winds become westerly around 00Z on Thursday. Upper-level divergence becomes more abundant in the early afternoon on Wednesday in mid-Missouri: leading to the development of lower-level convergence needed for storm production. This upper-level divergence is quick to pass and it heads to southeastern Missouri by the late afternoon leaving mid-Missouri clear for the remainder of the forecast period.

Meridional flow continues into the mid-levels of the atmosphere with the same deeply amplified trough-ridge pattern seen in the upper-levels. Strong areas of circulation are associated with the low-pressure system in the Northern Plains. There is also strong vorticity in central Missouri along the leading edge of a cold front that is draped from northeastern Missouri to southwestern Missouri.  Around 03Z on Thursday will be the greatest levels of vorticity for central Missouri. Circulation begins to weaken and eventually pushes eastward overnight and by 09Z on Thursday, there are little to no areas of circulation in central Missouri. As the low pressure system that originated in the Northern Plains heads northeast, the flow at the mid-levels becomes zonal as was shown in the upper-levels.

Moisture at the 700-mb level begins to increase throughout the day on Wednesday as winds from the south pull moisture from the Gulf of Mexico. By 00Z on Thursday, the winds shift to become westerly and any moisture is carried east out of mid-Missouri where it will remain dry at this level for the remainder of the forecast period. Negative Omega builds into mid-Missouri overnight tonight into Thursday but is replaced by positive Omega today and again on Thursday as this system continues to push eastward.


The low-level jet is situated in the same southwest to northeast pattern that was seen in the Midwest in the upper-level jet. The low-level jet stretches from eastern Texas to Michigan and has a jet streak that moves into Missouri but stays southeast of Columbia. Mid-Missouri stays on the outskirts of the jet stream throughout the forecast period. Winds from the south are pulling in moisture from the Gulf of Mexico, leading to a currently very moist atmosphere. Moisture gets pushed out of central Missouri around 00Z Thursday following the passage of the cold front after winds become northerly.

At the surface, a cold front has just passed through Columbia at 14Z on Wednesday. This will cause temperatures to cool throughout the rest of the day. Following the passage of the cold front, high pressure will begin to settle into central Missouri leading to a clearing sky and calmer weather for the remainder of the forecast period.

Soundings for this morning indicate that moderate rain will continue until 03Z on Thursday. A deep moisture profile can be observed until 03Z Thursday where the atmosphere becomes bone dry and will remain that way until 12Z Friday where there could be the presence of clouds. After the passage of today's showers, mid-Missouri will be clear of any precipitation throughout the remainder of the forecast period. As of 14Z Wednesday, Mizzou's campus had received just over 0.33" and by the end of the day, another 0.2" of rain could fall. This would bring rainfall totals for the day, and the forecast period, to around 0.5".

Future forecast shifts should continue to monitor the progression of rain today and update potential rainfall totals.

-Kobielusz