Tuesday Night: Small chance (10-20%) of light rain. Low: 37°F
Wednesday: Small chance (20-30%) for light rain/snow mix. High: 46°F
Wednesday Night: Decreasing Clouds. Low: 33°F
Thursday: Mostly Cloudy. High: 45°F
Thursday Night: Decreasing Clouds. Low: 33°F
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General Discussion:
Below average temperatures (30s and 40s) and small chances (20-30%) of precipitation Tuesday night into Wednesday morning. Light rain is forecast to start after midnight on Tuesday (tonight) and transition into a wintry mix after 7am Wednesday morning. Accumulation is expected to be trace amounts throughout Mid-Missouri by midday Wednesday. Expect clouds to linger and strong northwesterly winds on Wednesday, with sustained winds of 25mph, and gusts up to 40mph. This will contribute to dry conditions and temperatures remaining below average through Wednesday and Thursday.
Yost
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Forecasters: Yost, Thee
Date Issued: 04/02/2024 5:00PM CDT
Technical Discussion:
Key Messages:
- Small chance (20-30%) of light rain Tuesday night, with a brief rain/snow mix Wednesday morning. Precipitation is expected to start after midnight tonight and last through the late-morning on Wednesday
- Below average temperatures and dry conditions will persist through the rest of the work week.
Temperatures on Tuesday (high: 44F) have been much cooler than on Monday (high: 61F) due to a strong cold front that slid through Missouri Monday night. A well defined surface cyclone (992mb) is currently parked in northern IL tracking through the southern Great Lakes region and Ohio River Valley. This cyclone traversed the Mid-Mississippi Valley Monday night (last night), producing widespread thunderstorms, large hail, damaging winds, and even an EF-0 tornado in Chesterfield, MO. Since then, the unstable, moisture-laden air mass has shifted east with the aforementioned cold front. This weather system will continue to pose a severe weather threat across the Ohio River Valley into the Appalachian region, but a light rain chance will still be possible (10-20%) Tuesday night. By 12Z Wednesday, precipitation will transition to a rain/snow mix (20-30%). The 12Z Springfield sounding from Tuesday morning highlights a moist air mass lingering in the PBL which will set the stage for precipitation Tuesday night into Wednesday morning.
Current mid-level water-vapor satellite imagery shows a northern-stream shortwave trough pivoting across the CONUS with the axis intersecting the CWA. Deterministic model guidance depicts an elongated vorticity max rounding the base of the trough. The western periphery of the trough highlights an embedded shortwave that will roll through the CWA after midnight generating forcing for ascent to the low-level moisture already in place. Model soundings depicts a deep moist layer forming once the shortwave shifts through the region, but the PBL remains in the upper-30s and low-40s, so any precipitation that does form will fall as rain. Chances for any rain accumulation are low (10-20%), as deterministic guidance suggests a trace or less by 12Z Wednesday. Surface temperatures will continue to plummet overnight due to strong northwesterly winds causing low-30s by 12Z Wednesday. Even though surface temperatures will remain above freezing, most of the PBL is below freezing which will be conducive of a rain/snow mix for a brief period early morning. This moisture-laden air mass will quickly modulate and dry out by the afternoon on Wednesday so we expect a trace of precipitation by 18Z Wednesday.
Central MO will sit on the western periphery of the upper-level trough by Wednesday as an approaching ridge surges north across the Pacific Northwest. Surface analysis for Wednesday afternoon highlights a strong thermal/pressure gradient across the CWA which will contribute to strong northerly winds at 25 kts, and gusts up to 40 kts. Temperatures are expected to remain below average (avg. high 63) on Wednesday, and clouds are expected to decrease slightly Wednesday night ahead of an approaching surface anticyclone.
Weather conditions Thursday and Thursday night are very similar to that of Wednesday afternoon. The upper-level ridge will edge closer to the CWA, and the surface anticyclone will continue to advect cold air into the region contributing to below average temperatures (avg. high 63). Clouds will continue to decrease throughout Thursday night, but the CWA will maintain mostly cloudy conditions.
-Yost