Current Conditions at Sanborn Field 

             

Monday: Mostly sunny. High: 75

 

 

Monday Night: Clear. Low: 47

 

Tuesday: Mostly sunny. High: 74

Tuesday Night: Clear. Low 43

Wednesday: Sunny. High: 70

 

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Discussion:

A calm pattern of weather is in place over mid-Missouri to start off the work weak. Dry conditions are going to lend themselves nicely to sunny days, while a light, steady northerly breeze will contribute to brisk morning temperatures with pleasant daytime highs. 

 

 

-Schneringer

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Forecasters: Samson, Schneringer, Travis

Date Issued: 09/26/2022 9:00 AM CDT

Technical Discussion:

 

A much more fall-like pattern has taken shape over the U.S. with a longwave (LW) trough over the eastern half of the CONUS keeping flow at all levels of the atmosphere out of the NW for the duration of the period. The main concern going forward is how this flow will affect high and low temperatures. There is little to no difference between the GFS and NAM regarding large-scale features or temperatures. Deterministic solutions as well as MOS was used to forecast temperatures while the National Blend was completely disregarded due to high spread in the highs and lows.

A longwave trough present over the eastern half of the CONUS is helping a modest upper-level jet streak sag southeast through the Midwest. On the backside of this trough, the jet streak will provide weak forcing in the upper-levels coupled with near saturation. This is evident in current IR and WV imagery with thin, upper-level cirrus clouds infiltrating northern Missouri. By Tuesday, the wave and associated jet streak will be well to the east with little impact on the area. Having said that, a very weak shortwave will ride the back end of the exiting trough and move into mid-Missouri by Wednesday afternoon. Big emphasis is placed on WEAK with little upper-level forcing and very weak circulation seen in the divergence and vorticity fields respectively.

Additionally, mid- and low-level moisture is virtually non-existent. The NAM favors a brief spout of mid-level saturation ahead of the shortwave with some modest WAA which could amount to some alto clouds (however the GFS is far drier). In the low-levels there is no saturation to speak of in the region, and with dominant northwesterly flow, low-level CAA reigns supreme. This will keep temperatures way below what the region experienced this time last week. Largely clear sky conditions overnight will aid in efficient cooling allowing for chilly morning lows.

High spread in the NBM meant that deterministic guidance and some consultation with MOS was largely used. For Wednesday, deterministic models favored an 8-10 F difference in daytime highs from Tuesday with no identifiable reason as to why. As mentioned above, winds will, for the most part, stay out of the northwest/northeast will eventually transitioning to be out of the east by Wednesday. CAA in the low levels certainly exists, but is not significant in either model solution. As such, went a few degrees warmer than deterministic guidance for Wednesday's high. Future shifts should pay attention to this and adjust as needed.

Travis