Current Conditions at Sanborn Field

Tuesday: Increasing Clouds. High: 66

Tuesday Night: Partly Cloudy. Low: 48

Wednesday: Mostly Cloudy. High: 64

Wednesday Night: Mostly Cloudy. Low: 48

 

 

 Thursday: Cloudy with a chance of showers. High: 61

 

Thanks to IconArchive.com for the icons!

====================================================================

Discussion:

The sun will be out Tuesday so make sure to go out and get some sun. As the week progresses, more cloud cover builds in which will bring the temperatures down. While it will not be cold, the temperatures will be under the seasonal average.

-Meier

 =================================================================

Forecasters: McCormack, Peine, Smith

Date Issued: 4/25/23

2023 5:00 PM CDT

Technical Discussion:

 

The NAM was picked for this forecast because the GFS over-predicted much of the scattered rain showers seen over western Illinois earlier today. In addition, the NAM had a more accurate representation of showers in the Northeast.


The jet stream stays off to the south and east of MO. A trough has been and will continue to strengthen until 0z Thursday. At this time, it will be located over Kansas and begin to weaken and be absorbed back into the longwave upper level trough throughout the day Friday. This feature will start to weaken as the jet stream begins to strengthen and an area of divergence forms on the leading edge of the low. This area of divergence will stay relatively south of the mid Missouri region. The 500 MB vorticity map shows a circulation associated with the upper level trough but this again will stay to the south of mid Missouri. The vorticity lines up with the area of divergence hinting at the chance for more organized showers further south.


The upper level low is vertically stacked and can be seen lower in the atmosphere. There is an increase in moisture available associated with the low pressure system as seen on the 700 MB relative humidity map. This increase is most significant from 18Z Thursday to 9Z Friday. Also associated with the passage of this aforementioned low is a sharp uptick in lift as seen in the 700 MB omega map. However, the strongest areas of lift will remain off to the south in the Arkansas region. The moisture does not translate into the lower levels as the 850 MB dewpoint map shows relatively dry air in mid Missouri. This is likely due to the complete absence of any kind of low level jet completing shutting off low level moisture transport.


On the surface, a low pressure system starts over the middle of Texas and tracks across Arkansas around Thursday afternoon and into the evening. This system will bring an increased risk for precipitation for the area. However, since this low tracks so far south there will likely be little to no precipitation for mid Missouri. Additionally, if the low tracks more to the north like the GFS predicts, then the chance for rain increases; albeit precipitation totals will still remain low. When looking at soundings, the NAM never shows complete saturation while the GFS is fully saturated at the low levels for 12 hours.


Soundings show a general cloud cover for the length of the forecast regardless of precipitation. As a result, there won't be much in the way of diurnal heating so high temperatures will stay in the mid 60s. Lows will be in the mid 40s.

-Smitty