Current Conditions at Sanborn Field 

Friday: Mostly cloudy with thunderstorms and rain through the day. High: 75

 

 

Friday Night: Mostly cloudy, rain overnight. Low: 63

 

Saturday: Mostly to partly cloudy with light rain in the morning. High: 74

 

 

 

Saturday Night: Mostly cloudy chance for light rain overnight. Low: 50

 

 

 

Sunday: Partly cloudy becoming clear. High: 68

 

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Discussion:

The weekend will get off to a cloudy start, with precipitation expected ahead of a low pressure center heading towards Columbia. Thunderstorms possible through the morning and rain expected during the day and overnight on Friday, with totals around 0.35 in. Saturday is looking much the same with another chance for thunderstorms in the morning and slightly lower rain totals around 0.2 in. After that, a cold front will pass on Saturday leading to lower temperatures during the overnight hours. Sunday will be calm and fair with comfortable temperatures and partly cloudy skies.

- Ethridge

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Forecasters: VanUnnik, Ethridge, Bongard

Date Issued: 04/28/2022 5:00PM CDT

Technical Discussion:

 

The NAM was utilized for the majority of the forecast, though NBM was consulted for forecasting precipitation totals. NAM was chosen due to the better model consensus as opposed to GFS, as well as the depiction of the low pressure system and the associated trough over western CONUS. NAM also had a much better grasp on locating areas of divergence and circulation within the atmosphere. The problem of the day will be forecasting precipitation totals and timing, along with assessing the threat of potential thunderstorms. 

CONUS is captivated by a meridional flow this weekend, with three waves by Saturday. The main area of focus will be the low pressure system causing a negatively tilted trough in the upper levels over the western CONUS on Friday morning, which will evolve into a closed low that will pass through Western Iowa on Saturday morning, making its way to Minnesota and quickly travelling north by Sunday morning.

Due to the low pressure system, parts of Missouri will have divergence aloft throughout Friday night into Saturday morning. A westerly flow will dominate Missouri's winds aloft for the majority of the weekend. 

Few pop-up areas of circulation are evident over mid-Missouri at 500mb on Friday morning, and again Friday night into Saturday morning. The strongest circulation that will affect Missouri this weekend will be from the wraparound of the low pressure system over Iowa, with vorticity advecting into Missouri on Saturday afternoon and remaining through Sunday morning.

Relative humidity at 700mb will remain over Missouri from Friday morning to Saturday morning. Strong negative omega values are also present on Friday around noon, and again Saturday morning. 

An  LLJ will advect into Missouri late Friday morning, bringing strong southerly winds at 850mb. This LLJ will continue to impact the region before dissipating late Saturday morning. Loose WAA solenoids are depicted at the surface throughout most of the day on Friday.

Both the LLJ and the low pressure system to the west will impact wind flow in mid-Missouri. Friday will see a strong southerly flow, with a slow shift to westerly on Saturday, which should remain throughout Sunday.

On Friday, forecast soundings show CAPE values around 1500, K-index above 30, TT above 50, LI of -6, DCAPE from around 600-1,000, and PWAT values above an inch. CIN remains below 70 throughout. Heavy rain is expected on Friday, with thunderstorms expected to begin in the afternoon. These thunderstorms will continue throughout the night, not clearing until Saturday morning, when a cold front will desaturate and cool the area. After FROPA, Saturday and Sunday will be much clearer. Precipitation totals on Friday afternoon and night are anticipated to total around 0.35."

-VanUnnik