Current Conditions at Sanborn Field

 

 

 

Wednesday: Overcast. High: 47

 

 

Wednesday Night: Overcast. Low: 39
 

Thursday: Rain. High: 47

 

Thursday Night: Rain. Low: 34

Friday: Partly cloudy. High: 47

 

 

 

 

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Discussion:

A weak rainstorm is scheduled to pass through mid-Missouri on Thursday. Due to low moisture content within the atmosphere, expect accumulation between a quarter to a half an inch. The heaviest rain will be falling Thursday morning into the early afternoon, then transitioning into light rain and drizzle overnight.

In addition,

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Forecasters: Ritsema, Clark, Cochran

Date Issued: 03/08/2023 10:00 AM CST

Technical Discussion:

 

The GFS model was mainly used in this forecast due to the consistency and accuracy of storm tracks in recent weeks. Again this week, NAM's surface low track is considerably different than the GFS with the center of the low 100-200 miles to the east when passing over Missouri. 

Wednesday morning, leftovers from last nights active weather are lingering in the area. Vorticity and moisture at the 700 and 850mb levels will continue to move out Wednesday morning, clearing fully by midday(18z). Low level moisture will persist, though, leaving overcast skies throughout the day Wednesday. 

Thursday, a shortwave trough is set to influence mid-Missouri. On the surface, the low tracks from Oklahoma into mid-Missouri, eventually making its way into Illinois and out east.  Although unimpressive, the trough still brings along upper level forcing with divergence at the 300mb level between 12z and 18z. Raised levels of vorticity at 500mb exists for a short amount of time on Thursday between 06z and 18z, and the last ingredient for forcing is the weak, but widespread, omega throughout Missouri between 12z-21z. 

When looking at soundings, near-saturation exists at all levels beginning at 12z on Thursday. By 18z, the mid-levels of the atmosphere begin to dry out quickly. At 00z Friday, moisture only exists at 700mb and below and continues to dry out overnight. By 9z Friday, most of the moisture will have moved out of Missouri. 

The coupling of forcing and moisture present on Thursday will allow for rain to fall throughout the day Thursday. Heaviest rainfall will occur when forcing is present which is Thursday between 12z and 18z, transitioning to light rain and a drizzle overnight Thursday. Rain is expected to stop around 9z Friday. 12 hour QPFs from the NBM suggest around a quarter of an inch of rain throughout the day Thursday with less than a tenth of an inch overnight into Friday.

On Friday, the backside of the shortwave trough will be over mid-Missouri flushing in cooler dry air. Moisture is close to the surface which will produce low-level clouds.After the rain ceases, a low-level jet of 40kts from the northwest will influence stronger surface winds. Expect gusty conditions at the surface until 18z on Friday. 

-Ritsema