Current Conditions at Sanborn Field

Monday: Clear. High: 58

 

 

Monday Night: Clear. Low: 48

 

 

Tuesday: Cloudy. High: 59

 

 

Tuesday Night: Cloudy. Low: 53

 

 

 

Wednesday: Clear. High: 76

 

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Discussion: 

High pressure overhead will keep the region warm to start off the work week. Fall lovers will be disappointed to hear that near-record-high temperatures are expected for Wednesday as the high will be about 20 degrees above average! Clouds move in Tuesday afternoon into Tuesday night, but otherwise calm weather and plenty of sunshine is expected. 

 

- Travis

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Forecasters: Samson, Travis

Date Issued: 11/7/2022 9:00 AM CDT

Technical Discussion:

 

Another few days of above-average temperatures will eventually give way to a significant cool down at the end of the week thanks to an incoming amplified longwave trough. While both the GFS and NAM are in fairly good agreement regarding placement of planetary- and synoptic-scale features, leaned more toward NAM guidance as it likely has a better handle on moisture return associated with a weak shortwave early in the week.

With the LW trough that dominates the western third of the CONUS and upper ridge parked over the eastern half of the country, large-scale flow will remain predominately out of the southwest for the remainder of the forecast period. As the LW trough continues to amplify and dig into the Pacific NW, the jet stream, currently analyzed over the 46th parallel across the CONUS, will push north into Canada on the leeside of the Rocky Mountains. As the wave amplifies, a weak shortwave will propagate throught the region along the southwesterly flow. As mentioned above, with little dynamic support from the jet stream, it is unlikely this disturbance will result in widespread precipitation.

That said, model soundings show a deep layer of moisture late Tuesday night. The GFS is much more aggressive with moisture return associated with this disturbance. With a low-level ridge stationed over the Lower Mississippi River Valley, efficient moisture transport from the Gulf will be confined well to the west of mid-Missouri where a modest LLJ will develop. Additionally, as alluded to earlier, little in the way of dynamic forcing for ascent exists during this period. That said, WAA confined to the low levels will provide for some weak forcing. As such, while the probability remains low, some light rain should not be ruled out for overnight Tuesday into Wednesday.

With respect to temperature, this week will be impressive. Nearing record highs is certainly not out of the question with 500-hPa heights near or at all-time climatological maxima while 850-hPa heights will be at or above the 99th climatological percentile. The record high temperature for KCOU for Wednesday is 78F set in 1999. While it is not impossible that we may reach this, it is more likely that we will come up just shy as NBM 75th percentile high temperatures sit below these records. Nevertheless, Wednesday's high will still be about 20F above average. This will be a far cry from the end of the week where high temperatures will be below average.

- Travis