A large upper level low pressure system will move across the southern plains this week causing widespread showers and thunderstorms. The slow nature of the system combined with the upper flow parallel to the front will lead to high rainfall totals between Tuesday and Thursday.
Widespread 2-4″ of rain will be common across much of NW Arkansas from Fayetteville to Fort Smith. A few locations could pick up as much as 5″ or more of rainfall.
Flash Flood Watches are already in effect for most of NW Arkansas and could be extended farther south to Fort Smith.
Heavy rainfall and flash flooding will be the dominant threat. The weaker upper level winds will limit the tornado and damaging wind risk but it’ll still be present. The storm mode would likely be pulse or multi-cell leading to a quick intensification followed by a quick weakening as storm updrafts are choked with very high moisture content.
The highest severe weather risk will be on Tuesday evening across NE Oklahoma and NW Arkansas. There remains considerable uncertainty regarding evening evening storms which may (or may not) happen. The overnight round of storms appears to be locked in but the earlier round… should it develop.. would pose the higher severe weather risk.
More updates as event gets closer.