Wednesday Night: Partly cloudy, decreasing clouds. Low: 34
Thursday: Partly cloudy. High: 54
Thursday Night: Mostly cloudy. Low: 38
Friday Night: Mostly clear. Low: 33
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Discussion:
Thursday starts a cooling trend for the end of the week with highs in the middle 50s. Cloud cover increases that night as rain chances begin early Friday morning. Expect rain all day on Friday until the early evening, where we might get to see a few flurries. However, no accumulation is expected as the surface stays above freezing. Conditions dry out quickly, and precipitation will finish by dinnertime.
Forecasters: Chirpich, Cook, Travis
Date Issued: 03/01/2023 5:00 PM CST
The 12Z run of the GFS was chosen for this forecast, as it forecast the observed high temperature for Wednesday better than other models. The problem of the day for this forecast period is the low-pressure system currently located near California that is expected to bring precipitation to mid-Missouri late Thursday night.
The focus of the forecast will be the track of the aforementioned low-pressure system as it moves east. The trough formed by the low is currently positively-tilted as it sits over the western CONUS. However, the low-pressure system moves southeast, traveling through New Mexico and Texas before turning into a negatively-tilted trough by the time it reaches Missouri. The center of the low is expected to pass through the Missouri bootheel around 15Z on Friday. It will bring increased upper-level divergence, allowing for low-level convergence. While the low moves to the southeast of the forecast area, the wrap-around moisture associated with the southerly flow will allow for plenty of precipitation for the Midwest. Missouri will start to see increased dewpoints and cloud cover by 06Z on Friday.
It is also important to note that the 1000-5000MB thickness values stay above 5400m around the low-pressure system. This is a hint that winter precipitation might not be likely. However, soundings were consulted to give a deeper look into the possible precipitation type. The upper atmosphere begins to saturate at 03Z on Friday, with a pronounced dry layer seen at the surface. By 09Z, the zipper effect allows for the lower levels to become saturated. At this time, there is saturation at -10 degrees Celsius with a prominent warm nose and surface temperatures well above freezing, so precipitation will begin as rain. High negative omega values at 500MB and the surface were also seen at 09Z, leading to the heaviest rain expected early Friday morning. Rain will continue throughout the day on Friday until around 20Z, when the column begins to cool to just above 0 degrees Celsius. As the temperatures in the lower levels hover around freezing, it is possible that the area could see a switch to snow. However, as surface temperatures stay above the middle 30s, any snow that does fall will melt either before or as it hits the ground. This will not contribute any hazardous impacts for the event as no snow is expected to accumulate. Also, the atmosphere dries up by 21Z, quickly ending any possible snow or rain. Expected rain accumulation for the entire event will range between 0.5" to 1" of liquid precipitation, most of which will fall as rain.
No travel impacts are expected for the event, aside from wet roadways and possible reduced visibility in the early morning when the rain is heaviest. As conditions dry out, Friday night will be left with minimal cloud cover.
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