Heavy Rain and Thunderstorms in the Plains; Snow in the Northern Rockies; Heavy Rain in Guam

A storm system moving over the Rockies today will bring marginal risks for excessive rainfall and severe thunderstorms from parts of New Mexico into western South Dakota. Heavy snow expected from northwestern Wyoming into southern Montana. Ongoing heavy showers and thunderstorms from Invest 96W could result in localized flash flooding, particularly in central or southern Guam early this morning. Read More >

Overview and Graphics
Monthly Summary
Records

Overview and Graphics

September 2018 Climate Review: Temperatures were well above normal by around 5 degrees for the month. Paducah, KY and Cape Girardeau, MO finished as the 3rd and 4th warmest September’s on record respectively. High temperatures were routinely in the 90s through the first 21 days. In Paducah, KY there were 16 days that observed 90 degree temperatures, while there were 14 days in Evansville, IN and 12 days in Cape Girardeau, MO. The normal number of 90 degree days in September is around 5 to 6 days.

As for rainfall, the vast majority of the region finished wetter than normal. Amounts of 5 to 10+ inches were common for the month, which was some 2 to 6+ inches above normal. September is usually one of our driest months of the year too. The wettest locations were generally across portions of southern Illinois and southwest Indiana. On the flip side, there were a few areas in the Ozark Foothills of southeast Missouri that finished near or even slightly drier than normal. The heaviest rain was associated with the remnants of Hurricane Gordon on September 7th and 8th and from September 22nd to 27th as an active pattern set up across the region.

The graphic below is an interpolated rainfall map using actual observations. Please note that there are likely discrepancies in between observations, since the values are estimated based on nearest reports. Due to the convective nature of rainfall during the warm season, amounts are more likely to vary over shorter distances, compared to the cooler months.