Friday night: Spotty thunderstorms low: 68
Saturday: Partly Cloudy High: 83
Saturday night: Mostly Clear Low: 65
Sunday: Mostly Sunny High: 85
Sunday night: Partly Cloudy Low: 56
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General Discussion:
Temperatures across the region are expected to drop slightly overnight as a weak cold front sweeps through the region. Isolated thunderstorms are possible (50-60%) across Central MO along the front, but mainly south and east along the I-44 corridor. If you are heading home to St. Louis for labor day weekend, keep an eye out for stronger thunderstorms.
Yost
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Forecasters: Yost, Schwent, Slutter
Date Issued: 08/31/2024 5:00 PM CDT
Technical Discussion:
Key Messages:
- A weak cold front will shift through the region this evening, bringing spotty showers (50-60%) later this evening.
- Cooler temperatures and more stable conditions are forecast for the weekend, with the main cool down expected to make its way into the region next week.
A mid-level trough is ejecting across the Midwest this evening, with an associated cold front draped across MO. Convective activity is ongoing ahead of the front, mainly southeast of Central MO. Moderate instability (2000-2500 J/kg MLCAPE) and deep-layer shear magnitudes of 20kts are fostering scattered multicell thunderstorms, posing isolated damaging gusts and instances of large hail. The slow progression of the frontal boundary and subtle mid-level height falls through the evening may initiate some post-frontal convection. However, less favorable thermodynamics will limit the severe threat across the CWA. Nevertheless, a chance (50-60%) for a pop-up thunderstorm can not be ruled out Friday evening into the overnight hours. Rain totals will range from 0.1″ – 0.25″ if a thunderstorm does track through Central Boone County.
Model guidance agrees on large-scale subsidence behind the mid-level impulse with persistent northerly surface winds, bringing cooler, drier conditions into the region by Saturday morning. Lingering cloud cover Saturday morning should diminish through the afternoon as surface high pressure to the west slowly meanders eastward into MO. Temperatures are expected to be near average (avg. high 85F) through the weekend before a more robust anticyclone tracks southward from Canada, bringing stronger CAA and below average temperatures (avg. high 85F) by Monday morning.
Yost