Wednesday: Mostly Sunny.High: 92°F    

Wednesday Night: Partly Cloudy. Low: 66°F    

Thursday: Cloudy, Showers likely (60%). High: 89°F    

Thursday Night: Cloudy, Showers possible (20%). Low: 68°F 

Friday: Decreasing clouds. 85°F 

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General Discussion:    

Clouds increase by Wednesday with showers becoming more probable by Thursday afternoon (60%). Clouds stick around into Friday along with a slight cool down into the weekend with highs in the mid 80s, still slightly above average for this time of the year. 

• Nightingale, Halter, Wyrick 

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Forecasters: Nightingale, Halter, Wyrick 

Date Issued: 09/17/2025 9:00 AM CST    

Technical Discussion:  

Key Messages:    

• Relative Humidity increasing along with clouds Thursday increasing probability of showers (60%). 
• Slightly cooler air moving in following a trough coming in from the west (about 5-10° cooler than previously).

The GFS Models were used because of their lack of moisture bias.

Wednesday 

Missouri is currently experiencing a NW flow with weak upper level winds, indicating a relatively dry atmosphere. A trough located to the west begins moving towards the central plains, bringing along with it wind divergence aloft. Relative humidity at 700 mb increases Wednesday mid morning (70%) indicating increasing cloud cover for the area. In the lower levels, winds shift from NW around Wednesday at 15Z with Southerly flow remaining until the end of the period, which signifies moisture and warmer air. 

Thursday

Around 06Z, a relatively neutral trough from the west plains moves into Colombia enhancing the existence of a baroclinic atmosphere. Positive circulation at 500 mb entering from the west accompanies the trough providing favorable conditions for precipitation later in the afternoon. Relative Humidity values (>75%) increase starting Thursday indicating enhanced chances of precipitation for Thursday afternoon and Thursday evening. At 03Z on thursday, vertical velocity is more abundant in the area. When coupled with the trough at the 700 mb level, precipitation is likely at this time. It is important to note that the low is positioned to the Northwest of Missouri, so it is likely a pretty weak system that Missouri is experiencing residual effects from such as cloud cover, showers, etc. The GFS soundings indicate precipitation patch Thursday afternoon and evening with a saturated atmosphere and PWATs around 1.5”. Rain chances will be the greatest starting Thursday at 06Z and persisting through Friday at 15Z with about 0.2” expected. 

Friday 

A slight cool down is indicated by the CAA succeeding the shortwave that moved through Missouri overnight. Relative Humidity values in the upper levels, indicated by a 12Z sounding on Friday, show the possibility for remaining cloud cover. Temperature imaging at the surface reveals rain cooled air with highs in the mid 80s, about a 10 degree cool down from the previous week. Future forecasters should note that while a slight cool down follows the rain, models also suggest WAA moving into the area for the later parts of the weekend which could mean the atmosphere is heating up again. 

• Nightingale, Halter, Wyrick