Current Conditions at Sanborn Field         

Thursday: Clear. High: 64

  

Thursday Night: Sunny. Low: 39

 Friday: Partly Cloudy. High: 69

  Friday Night: Overcast. Low: 43

  

   

Saturday: Mostly Sunny. High: 67

 

 

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Discussion: 

Cold temperatures take over after the passage of the cold front. Today's afternoon will be windy with a sunny sky. Clouds will move in on Friday, raising overnight lows, and will clear out by Saturday afternoon. Winds will also calm down on Saturday. Surface conditions will be dry throughout this forecast, so avoid burning any leaves as we are in elevated fire weather.

- Sausen

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Forecasters: Baker, Sallot, Sausen, Thomas

Date Issued: 10/13/2022 9:00 AM CDT

Technical Discussion:

Due to very similar handles on current conditions, both the GFS and the NAM were used to construct this forecast. Both models show the jet stream following a longwave trough, and passing over the CWA for the entire forecast period. A significant jet streak is expected to pass over the CWA on Thursday from 15Z to 21Z. While the models agree in the placement and timing of the jet stream and jet streak, there was some disagreement on the strength of the jet streak and divergence; the GFS indicates both a stronger jet streak and much more divergence than the NAM.

At 500 mb, higher vorticity is expected around 18Z to 21Z in conjunction with the jet streak at 250 mb. However, another band of vorticity is expected on Friday from 09Z to 15Z, but this vorticity is not associated with the passing jet streak. A shortwave trough moves from the west into the Great Plains region. While this will not reach the CWA during the forecast period, future forecasters should be aware of this approaching shortwave.

Another discrepancy between models is evident at 700 mb moisture, where models agree on the beginning of increased moisture for the CWA on Friday at 21Z but disagree on how long this moisture persists. The GFS leans toward conditions drying out around 00Z on Saturday, but the NAM holds onto the moisture until Saturday at 03Z. Despite this discrepancy, both models show warm air advection on Friday at 09Z to 15Z which correlates with the band of vorticity at 500 mb. Supported by model soundings, these conditions support upper level cloud formation Friday afternoon and evening. Dry lower levels discourage any precipitation for the forecast period.

Temperatures are expected to reach mid to upper 60s during the day and fall to upper 30s to low 40s throughout the forecast period. Upper level forcing related to the jet stream overhead is encouraging stronger winds at the surface, especially from the west and northwest. These winds coupled with dry low levels support fire weather conditions, especially on Thursday.

-Sallot