St. Louis region forecast stays calm through Saturday, with widespread rain and thunderstorms returning Sunday

What to expect through the weekend

The St. Louis region is on track for a relatively quiet stretch of weather through Saturday, followed by a return to unsettled conditions on Sunday as a new storm system moves into the central United States. The overall pattern supports a transition from dry-to-partly dry conditions late this week into increasing moisture and stronger winds this weekend, culminating in rain and thunder chances Sunday.

Thursday through Saturday: Limited precipitation, seasonal swings

Forecast guidance for the metro indicates mostly dry conditions through Friday and into much of Saturday, with periods of clouds and sun and temperatures trending milder by Saturday afternoon. Winds will increase at times, particularly as southerly flow strengthens ahead of the next system. While the period is expected to be generally calm, the weekend does not appear completely precipitation-free: low-end rain and thunder chances may begin late Saturday night as the atmosphere starts to moisten and lift increases ahead of Sunday’s main event.

• Through Saturday daytime: largely quiet, with breezier intervals and improving temperatures compared with late-week chill.
• Late Saturday night: a small but increasing chance of showers and thunderstorms developing as the next system approaches.

Sunday: Rain likely, thunderstorms possible

Sunday is expected to bring the more widespread impacts. The latest point forecasts for the St. Louis area show rain becoming likely on Sunday, with at least some potential for thunderstorms during the day. Wind is also expected to be a factor, consistent with a stronger spring-like storm system passing through the Mid-Mississippi Valley.

Thunderstorm intensity will depend on how much instability can develop and how quickly the system moves. Even when confidence is high that rain will occur, the corridor and timing of any stronger storms can shift as the event gets closer, particularly across the boundary between stable air north of the track and warmer, more unstable air to the south.

Key planning takeaway: conditions remain manageable through Saturday, but Sunday increases the risk of weather disruptions from rain, gusty winds, and embedded thunderstorms.

How to plan around changing conditions

Residents with outdoor events through Saturday should have workable conditions overall, though breezy periods are possible. For Sunday, plan for wet roadways and reduced visibility at times, and allow extra travel time. If thunderstorms become stronger than currently indicated, localized impacts could include brief downpours and stronger wind gusts.

• Schedule outdoor work and errands earlier in the weekend where possible.
• Check updated hourly forecasts Sunday morning for timing shifts.
• Have a method to receive watches and warnings if thunderstorms intensify.