We live in a very unique part of the country. Our topography changes all throughout our viewing area, and that same topography also causes major changes in our weather. Take this afternoon for example. Ft. Smith cooked to near 90 degrees, but didn't see a drop of rain; however, sections of LeFlore county saw the same warm temperatures, along with some heavy rainfall, so what caused the difference?



Take a look at the surface map above. We've seen a stationary frontal boundary sit across our area over the last couple of days. This boundary has had enough convergence along it to allow for afternoon thunderstorm development. This boundary got a little boost today setting up across portions of the Ouachita Mountains. The mountains helped to orographically transport air high aloft in the atmosphere, creating showers and storms.



Looking at this surface map we clearly see Ft. Smith is receiving a northeasterly wind. Now, keep in mind, the elevation in Ft. Smith is right around 500 ft; moreover, that wind is heading southwest toward Poteau with an elevation of 2,385 at Cavanal Mountain, so the air is being forced up the side of the terrain. South of Poteau we were seeing more of a southerly wind this afternoon. That air was also being forced up the back side of the terrain. The two separate winds converged, where the air can only rise up! This enhanced area of lift could only be created by the mountainous terrain.



Some spots had picked up between .50" to 1.00" of rain from this localized event, where 25 miles away, the ground remained dry in Ft. Smith. It's either feast or famine this time of the year!