Current Conditions at Sanborn Field

Wednesday: Rain. High: 56
 

 

 

Wednesday Night: Rain ending. Mostly cloudy. Low: 50

 

 

Thursday: Partly cloudy. High: 73

 

 

 

Thursday Night: Building clouds with a chance of thunderstorms. Low: 63

 

 

Friday: Partly cloudy. Warmer. High: 83

 

 

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Discussion:

It's going to be one wet and wormy Wednesday. As showers continue off and on throughout the day today, those worms are once again going to make their appearance on campus sidewalks. It may be a better idea to keep that rain jacket handy rather than an umbrella as the rain is going to be accompanied by winds gusting near 35mph. Rain will be off and on throughout the day today before ending in the late evening. That doesn't mean you can pack the rain jacket back in the closet though: there are more chances for rain Thursday. This second round of showers will begin Thursday evening and end mid-morning on Friday. A rumble of thunder or two is possible but severe weather is not expected. Rainfall totals through the end of the week will be around an inch. Despite the rain, temperatures will be on an upward trend and will be above average to end out the week.


-Kobielusz​=================================================================

Forecasters: Macko, Kobielusz, Bongard

Date Issued: 04/20/2022 10:00PM CDT

Technical Discussion:

 

The 06Z runs of both the NAM40 and the GFS20 have been able to match current conditions quite well, particularly in the areas of current temperature and placement of frontal boundaries. The NAM40 was selected over the GFS20 for this forecast period due its better grasp on the placement of the low-pressure system in far western Kansas early Wednesday morning. It is this low-pressure system that will impact Columbia's weather in the days to come. Soundings and SREF plumes were also utilized to determine convective potential, temperatures, and precipitation accumulations.

250-mb wind plots indicate a predominantly zonal flow across the CONUS. The only exceptions to this statement include a deep, upper-level trough over the Atlantic and an upper-level shortwave trough over the Central Plains around 15Z Wednesday. This shortwave will track steadily toward mid-Missouri, where it is expected to remain from 23Z Wednesday to 05Z Thursday. Zonal flow will return following the passage of this shortwave before upper-level ridging takes hold over the Great Plains. Mid-Missouri will remain out of jet influence for entirety of the forecast period as the jet is expected to stay north. Similarly, no upper-level divergence is evident. By Friday evening, a well-defined trough-ridge-trough pattern has developed over the CONUS. The western trough may influence the weather heading into the weekend as it moves eastward, and future forecast shifts should mind its evolution.

The shortwave seen at 250 mb is also evident at 500 mb and impact mid-Missouri during the same time frame. Vorticity associated with this shortwave will exit the Columbia area just after 00Z on Thursday. Vorticity will not make another return to Missouri through the rest of the forecast period, as zonal flow followed by ridging will occur through the end of Friday. However, by Saturday morning, a significant swath of circulation is located over the western Plains states, something that may impact conditions over the weekend.

Negative omega is prevalent in Missouri in during the overnight hours on Wednesday into Thursday, potentially resulting in some lingering precipitation following the passage of the shortwave in the upper levels. Plentiful moisture exists at 700 mb on Wednesday before the layer dries out considerably by 00Z Thursday. By late morning on Thursday, positive omega will once again prevail under ridge control.

 

850-mb moisture transport vectors indicate that there will be a significant moisture supply from Wednesday into the early morning hours on Thursday. After this point, moisture will not be reintroduced to the region until late Thursday night into Friday morning.

Forecasted soundings for Thursday night into early Friday morning suggest the possibility of convection. However, there is a lack of low-level forcing associated with the passage of a warm front around that same time. This will inhibit any significant convection, and thunderstorms should be on the generic side. Low-level forcing should be monitored in the forecast shifts leading up to Thursday evening, as sufficient forcing may be enough to result in a severe storm. Soundings for Friday imply high values of CAPE and LI between -6 and -8. However, very little moisture appears to be available during this time. Low-level moisture content should be watched carefully over the next few shifts.

PWAT values decrease throughout the day on Wednesday, suggesting that rainfall will end late Wednesday evening. PWAT values will increase once again during the daytime on Thursday, leading to late evening rain. SREF output suggests that total rainfall accumulations will be no greater than 1".

- Macko