This means something on a very small scale, perhaps on the order of tenths of a mile, higher or lower rainfall totals may occur, but forecasting down to that specific square tenth of a mile is not possible. However, we often follow that up by saying that “locally higher amounts are possible” or “some areas may miss out and see less than 1”. If we say 1” to 2” of rain is likely within this area, that means that within that 25-mile radius (within the circle) the most likely outcome is 1” to 2” of rain. For example, let’s take a 25-mile radius around Mount Pleasant and draw a circle. Forecasting is done by determining a certain radius within any given location and predicting the probability of something happening within that mathematical area. First of all, forecasting for your backyard is not possible. This is a good time to explain what we mean by “localized” or “locally higher amounts possible” when communicating forecasts to you. What is another big takeaway as to why this is being classified as a 1 in 1,000 Year Flood? In just 6 hours, 7.68” of rain was measured, which quite literally has less than a 1 in 1,000 (<0.1%) chance of occurring in any given year.įurthermore, the localized scenario of this event was also fascinating. Louis recorded 9.04” of rain, which not only set an all-time daily record, but also provided more rain than would typically fall in both June and July combined. During a 24-hour period, the official observing site in St. Louis this past week statistically had a 0.1% chance of happening in any given year. True, sometimes you do hear the term floating around ahead of a potential flooding event that is being forecasted as a possible 1 in 1,000 year event, but in reality, because floods of this magnitude are so rare, forecasting them accurately is simply not possible. Although this may seem like a term that would be used to describe only a rare event or to hype something up in the media, that simply isn’t the case this time around. Interestingly, it was so incredibly extreme, that the flooding is being considered a 1 in 1,000 year event or a 1 in 1,000 year flood. The heat then builds back in with upper-80s to near 90° favored for highs this weekend.Ī Catastrophic Flash Flooding Event occurred last week on July 25th and 26th in St. A cold front will drop temperatures into the lower-80s for highs on Thursday and Friday, which is also when low temperatures in the 50s are likely Friday and Saturday morning. Additionally, Showers and Thunderstorms are likely with heavy rain. Strong winds will blow in very warm air, which will result in high temperatures of 90° to 95°. Mostly Sunny skies are forecast on Tuesday with highs in the lower-80s. For today, the best chance for Showers and Thunderstorms will be this morning, although a shower could linger into the afternoon. There are two chances for thunderstorms this week and temperatures will range from the 90s to the 50s.

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