Current Conditions at Sanborn Field
Wednesday Night: Cloudy. Rain beginning after midnight. Low: 34
Thursday: Cloudy with AM rain. Freezing drizzle possible in AM before switching to sleet. High: 35
Thursday Night: Sleet transitions to flurries, drying out by late evening. Low: 20
Friday: Sunny. High: 37
Friday Night: Clear. Low: 26
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Discussion:
Rain begins tonight and continues into tomorrow morning. Thursday morning also has the potential for a burst of freezing drizzle, but by noon expect to start seeing sleet. Hazardous road impacts are not expected, but just be sure to give extra time to warm your car Thursday morning to defrost your windshield! We will end Thursday evening with a few flurries before transitioning to a clear and dry Friday.
-Chirpich
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Forecasters: Cook and Chirpich
Date Issued: 2/15/2023 5:00 PM CST
The 12Z run of the NAM was chosen for this forecast as its forecast temperatures for Wednesday afternoon better matched the observed temperatures for the forecast area. The problem of the day for this forecast period is the shift between multiple precipitation types between Wednesday night and Thursday night.
A Colorado low will make its way into Missouri early Thursday morning, and will cause a range of precipitation types for the forecast period. The trough associated with the aforementioned low-pressure system puts mid-Missouri in a meridional flow, signalling the tumultuous weather on its way. As the system moves through, ample forcing was found, evidenced in the upper-level divergence shown at 300MB around 06Z on Thursday. At this same time step, increased circulation was seen at 500MB, along with moisture moving into the region at 700MB. This time (midnight on Wednesday) where the forcing, lift, and moisture coincide, is expected to be the catalyst for the beginning of precipitation. There is also a weak LLJ seen at 06Z, further supporting the moisture transport needed for precipitation. Soundings show a few different stages of precipitation type, with the first wave Wednesday night being rain that begins after midnight, lasting into the early morning. Between 13Z and 16Z on Friday, temperature profiles indicate a possible switch to freezing drizzle, then transitioning quickly to sleet. Measurable precipitation is not expected to exceed 0.5" of liquid accumulation for the entire passage of the system.
The low-pressure system will continue to bring the moisture needed into the region until Thursday at 18Z, when a dry slot was seen at 700MB. This coincides with forecast soundings that indicate a drying of the atmosphere that evening. Cooling upper-level temperatures at this time will allow for a switch from sleet to snow flurries. The flurries are expected to end by the late evening with cloud cover sticking around overnight. No accumulation is expected due to above-freezing surface temperatures and a saturated ground from Wednesday night's rain. High pressure then builds in on Friday, with clear skies and sun returning for the weekend. Solenoids were also seen Saturday around 12Z, signalling WAA to increase temperatures for the weekend.
-Chirpich
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