St. Louis, MO — A quiet but cooler Sunday sets the stage for a much more active weather pattern heading into next week across the St. Louis region. Despite abundant sunshine today, highs will only reach the mid-50s to mid-60s, a noticeable drop compared to recent mild days. Light winds will keep conditions pleasant, but the cooler air hints at the changes ahead.
Beginning late Monday, the first in a series of disturbances will sweep across Missouri and Illinois, bringing scattered showers and possibly a few thunderstorms. Rain chances increase to 60–80% by Monday night, especially for areas east of St. Louis and into Illinois. This initial round is not expected to bring heavy rainfall, but it marks the start of a wetter stretch that will persist through much of the week.
Tuesday brings lower, more scattered rain chances, but by Wednesday afternoon and evening another, more potent system approaches. This mid-week disturbance is expected to bring widespread rain from Wednesday night through early Friday, with rain chances peaking between 70–90% across the region.
Forecast rainfall totals show strong signals for a meaningful soaking. Most areas around and east of the Metro appear headed for 1.25″ to 2.25″ of rainfall by Friday morning. Current projections show St. Louis likely falling in the 1.00″ to 1.90″ range, Columbia 0.90″ to 1.50″, Quincy 1.50″ to 2.00″, and Farmington and Salem, IL in the 1.00″ to 2.10″ range. Probabilities for at least 1 inch of rain range from 70–75%, with a 30–35% chance of exceeding 2 inches, especially into Illinois.
While widespread flooding is not anticipated at this stage, areas that see repeated downpours could experience ponding or minor drainage issues.
Residents should prepare for several wet commutes Wednesday night into Friday morning and monitor potential updates as the storm track becomes more refined.
