Thursday, April 3rd, 2025 Evening Forecast, 5:00 PM CDT
Thursday Night: Cloudy. Low: 46°F
Friday: Persistent rain in the afternoon with a 80% chance of thunderstorms. High: 52°F
Friday Night: Showers continue through the night with a 50% chance of thunderstorms. Low: 46°F
Saturday: Cloudy with rain persisting. High: 51°F
Saturday Night: Cloudy with drizzle persisting. Low: 36°F
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General Discussion: Rainfall will be consistent across the forecast area with 2-3” of accumulated rainfall likely throughout the forecast period. Friday evening into early Saturday morning consists of a Marginal Risk of severe weather across mid-Missouri with heavy rain, localized flooding and small hail being the main hazards. The rain will slowly taper off Sunday morning.
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Forecasters: Alcorn, Franciscus, Yost
Date Issued: 04/03/2025 5:00 PM CDT
Technical Discussion:
Key Messages:
- Localized flooding is possible across mid-Missouri with 2-3” of accumulated rainfall throughout a three day period.
- Thunderstorms are likely across the forecast area Friday evening into Saturday morning, though small hail and localized flooding cannot be ruled out.
In the upper levels of the atmosphere, as of Thursday 21:00Z, a high pressure system is currently building in the Caribbean and Florida Keys regions. Concurrently, a positively tilted trough remains dormant over the western United States, with the Midwest and mid-South region being in the right entrance and exit regions. The high pressure will serve to block this trough from translating eastward for the duration of the forecast period, allowing for multiple rounds of acclimate weather throughout Friday and into the weekend. The high pressure system will also slowly move eastward and diminish with time, allowing for the trough to also move eastward. A somewhat modest jet streak is expected to develop over Baja California at Saturday 6Z, and will round the base of the trough Sunday 0Z, where the trough will begin a weakening trend towards the end of the forecast period. With this trough remaining in the same spot, mid-Missouri will be in the middle of constant difluence with the spreading of wind vectors occurring at almost all times.
For Thursday evening, rain is anticipated to move out of mid-Missouri, allowing for a break in the rainfall until Friday 16:00-18:00Z. A stationary front is draped across the mid-South, with it expected to surge slightly northward placing portions of mid-Missouri into the warm sector, allowing for some instability to build across the region. With the presence of moisture in mid-Missouri throughout the mid and lower levels of the atmosphere, the wind barbs being southerly from 850 MB to 500 MB advecting ample moisture, constant diffluence in the upper levels and multiple shortwaves occurring across Missouri throughout the afternoon and evening Friday will allow for consistent convection to form. Some of this convection has the opportunity to become thunderstorms, mainly in the evening and overnight hours. Any storms that develop in this environment will be elevated in nature, with the LCL being at 750 MB. MUCAPE during this time period differs with each model, but the NBM and SREF are in agreeance that it could exceed 1000 J / kg at times. However, due to the lackluster hodographs and elevated nature of the storms, the only real severe threats will be locally heavy rain, as convection is expected to train over the same regions repeatedly, and some small hail. This training regime could lead to localized flash flooding for Friday night into Saturday morning for regions in the forecast area, particularly those nearest to the stationary front in southeastern Missouri. Models differed with the positioning of the stationary front, with the NBM and HREF showing the front more northwest, so rainfall totals could differ drastically, dependent on where the stationary front positions itself in this duration. More shortwaves at 700 MB associated with the dormant trough will ignite convection in middle Texas during the overnight hours.
The rain is expected to taper off early Saturday morning with a break expected with lingering cloud cover. The aforementioned convection, will be forced to straddle the stationary front to its southeast and a newly formed cold front to its northwest, advecting this rain into the forecast area, leading to another round of showers. Though, with no instability present at this time, the severe threat is lackluster.
Though, with the multiple rounds of rain expected, localized flash flooding is a real threat with the NBM, HREF and SREF all agreeing that 2-3” of rainfall is in the realm of possibility. However, as previously mentioned, the aforementioned stationary front positioning could affect rainfall totals, with some regions possibly seeing more / less rain. The rain will gradually taper off Saturday night, as the dormant trough finally moves its way eastward across the Great Plains and weaken, lessening its impact in the mid-South regions.
Alcorn