Current Conditions at Sanborn Field

Tuesday: Clouds decreasing throughout the day. High: 39

 

 

 

Tuesday Night: Mostly clear. Low: 23

 

 

Wednesday: Increasing clouds throughout the day.High: 33

 

 

Wednesday Night: Mostly clear. Low: 21

 

 

 

Thursday: Partly sunny. High: 39

 

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Discussion:

Following our snowfall last night, mid-Missouri will remain in a wintry weather pattern. While we will remain dry, our high temperatures this week will remain below 40 F with varying amounts of cloud cover each day. A southerly wind shift on Thursday will help to warm us up from Wednesday, but only by a few degrees.

 -Clark

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Forecasters: Ritsema, Clark, Baker

Date Issued: 11/15/2022 9:00 AM CST

Technical Discussion:

 

Both the GFS and NAM were in concurrence for much of the forecast period, so both models were used for this forecast. Our temperature forecast used the NBM, as both the GFS and NAM have been underestimating daily temperatures, while the NBM has been performing well.

At 300 mb, the subtropical jet is currently over the Southern CONUS with a jet streak stretching from Oklahoma to Tennessee. As it moves off to the east, a trough associated with a low pressure center over Ontario will pass though Missouri from Thursday 00z to 09z. Following this trough is a jet streak associated with the polar jet which will enter Missouri around Thursday 21z. Due to the position of the jet stream to the south of MO as well as the lack of divergence at this level, a calm weather pattern is expected this week.

 

At 500 mb, Missouri is under the influence of high vorticity associated with a low pressure system over the Dakotas. As the low pressure located over the Dakotas moves into Ontario and Quebec, a 500 mb trough will bring more broad vorticity to Missouri around 18z Wednesday. As this trough passes after 06z Thursday, the broad area of vorticity moves off to our east. If supported by mid-level moisture and forcing, consistently high vorticity from Tuesday to Thursday 06z will aid in the formation of clouds. 

Despite saturation at 700 mb Tuesday morning, around 15-18z the 700 mb layer will dry out and remain dry over mid-Missouri until  Thursday 12z, when moisture advection will bring in a broad area of saturated air from the Rockies. Additionally, throughout this week no significant amount of vertical velocity will be associated with mid-Missouri, leading to a lack of clouds at 700 mb.

At 850 mb, moisture will remain in our area until Wednesday 06z. Strong northerly winds at this time will push the saturated airmass off to the east and leave mid-Missouri with dry air and cold surface temperatures due to cold air advection. The air will saturate again Wednesday around 18z as a moist airmass is advected into the area by the strong northerly winds. The area of saturation is associated with areas of warm air advection, which will result in lift and cloud formation. Thursday morning will see few clouds due to a lack of moisture at this level, however they will build in as the day progresses.

At the surface, temperatures will remain cold throughout the forecast period. Temperatures will decrease through Tuesday into Wednesday due to NW winds before increasing again on Thursday due to a SW wind shift around 06z Thursday. This wind shift is due to the presence of a high pressure system over Arkansas which originated from the Western US, which will move from the Rockies on Tuesday to Arkansas on Thursday. As the high pressure enters Arkansas, it will shift Missouri winds to the SW between 06z and 15z, before it moves off to the east and MO winds return to a NW pattern. 

-Clark