Monday, April 15th – Afternoon Forecast
Monday Night: Light rain late. Low: 65°F
Tuesday: Severe storms possible in the afternoon. High: 76°F
Tuesday Night: Partly Cloudy. Low: 57°F
Wednesday: Mostly sunny, breezy. High: 70°F
Wednesday Night: Partly cloudy. Low: 53°F
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General Discussion:
Two rounds of severe weather are possible for Central Missouri. The first one Monday night into Tuesday morning, and the second one from Tuesday afternoon into the evening. All severe hazards including large hail and tornadoes are possible. Accumulation is expected for Columbia as the storm system moves through Tuesday. A warm up trend will occur through Wednesday after the front comes through.
-Beam
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Forecasters: Beam, Jackson, Sallot
Date Issued: 04/15/2024 6:00 PM CST
Technical Discussion:
Key Messages:
- Severe Weather Possible Monday night – Wind and hail main threats
- Severe Weather Possible Tuesday – Tornadoes and hail main threats
- Warm-up trend
An upper-level “bowling ball” low will continue to undergo lee cyclogenesis through the rest of the day today (Monday), bringing a chance of severe thunderstorms across the Midwest. A surface warm front will be draped across Missouri, leaving the possibility of storms to fire along it tonight low (30%), but nonzero. This warm front will drift north slowly through the night and into tomorrow morning, where a more formidable atmosphere across Central and Northern Missouri will shape up. As the upper-level low migrates to the northeast, ample moisture will be streaming northward out ahead of it across Missouri and Iowa Tuesday morning. This will set up a dryline/cold front combo that will progress east through Kansas and into Missouri during the day Tuesday. Convection will fire along the dryline late tonight and be ongoing across Kansas and Western Missouri by Tuesday morning, this rain and thunderstorms will move east into Tuesday morning. The coverage and intensity of this morning precipitation will impact the overall severity tomorrow afternoon! Most CAM’s show the bulk of the rain missing Central Missouri to the north, leading to a low chance of accumulation.
As the surface low moves through Northern Nebraska, the warm front will continue surging north into Central Iowa. This causes an issue with storm initiation across Central and Southern Missouri Tuesday afternoon. With the warm front in Iowa and the dryline appearing weaker through Central Missouri, storm initiation will be focused with a mid-level shortwave moving through. The shortwave looks to clip Central Missouri and move just to the north, lowering the coverage of storms to around 50% in Columbia. However, up in Northern Missouri/Southern Iowa, with the tighter moisture gradient along the dryline and the shortwave that will move through Tuesday afternoon, the chance for thunderstorms redeveloping will be high (70-90%).
If any storms develop across Central Missouri, they wouldn’t have any trouble becoming severe. The NBM shows a range of CAPE values for KCOU from 1000-2000 J/kg after the morning rain moves through. Clouds should clear out during the early/mid-afternoon before storms redevelop tomorrow afternoon/evening. Analyzing a 21z Tuesday HRRR sounding for KCOU. CAPE values in excess of 1500 J/kg, sfc-3km lapse rates >7.5 C/km and a lifted index of -6 hint toward instability not being a problem across Central Missouri. With a large dry layer just below 500mb, the hail risk seems moderate. Surface winds are not backed, but show gradual veering with height, meaning any storm that redevelops behind the morning storms will be supercellular in nature. The tornado threat is nonzero across Central Missouri, but will be higher across Northern Missouri and Southern Iowa where surface winds will be more backed. Cold air advection around 700mb will erode any cap that does try to form, so storms will be free to initiate across Northern Missouri and Southern Iowa. As for Central Missouri, large hail and a brief tornado or two cannot be ruled out with any storm that develops in the afternoon. As for Northern Missouri/Southern Iowa, storms are likely to develop in the afternoon and an isolated chance for a stronger tornado exists in the area that has more surface backing of winds and clearing through the day tomorrow.
The cold front will move through Wednesday morning and temperatures will slowly drop behind the front, then quickly rebound. Future forecasters should watch the new system that will come in on Thursday.
-Beam