Mesoscale Precipitation Discussion 1470

 **10.39am on 10-10-2026**

Heavy rain and possible flash flooding are expected in southwest North Carolina (including the Macon County area) this afternoon.

Showers and thunderstorms are increasing as moisture flows into the Southern Appalachians from a lingering tropical system. Rainfall rates could reach 1–2 inches per hour in spots, with another 2–4 inches possible through mid-afternoon. The biggest concerns are in the higher terrain of southwest NC and upstate SC, where water can run off quickly into creeks and low-lying areas. Some flooding of roads or small streams is possible, especially later this afternoon.

---BEGIN SPONSOR SEGMENT---

WEATHER SPONSOR

The weather is being sponsored by the Caleb for NC Campaign. Caleb is running for the NC House in District 120. Read more about his campaign at https://calebbrownfornc120.com.

DAY SPONSOR

This space available

---END SPONSORED SEGMENT---

xxxxxxxxx

Mesoscale Precipitation Discussion 1470

NWS Weather Prediction Center

College Park MD

1030 AM EDT Sat Oct 10 2026

Areas affected...Portions of the Southern Appalachians and Interior Southeast

Concerning...Heavy rainfall...Flash flooding possible

Valid 101430Z - 102030Z

SUMMARY...Flash flooding will continue to be possible through mid-afternoon as rainfall rates gradually increase with time. Short-term urban impacts may occur across north-central to northeast GA, with more terrain-focused impacts becoming a concern across upstate SC and southwest NC this afternoon.

DISCUSSION...The latest GOES-E IR/WV suite shows a well-defined TROWAL axis pivoting across large areas of the Southeast U.S. around the eastern flank of what is now Post-T.C. Isaias. Deep layer moist east to southeast flow into the southern Appalachians and adjacent Piedmont areas of the Southeast will combine with a gradual uptick in instability with the diurnal heating cycle to promote a gradual increase in the coverage and intensity of shower and thunderstorm activity going through the mid-afternoon hours. This will be aided by divergent flow aloft downstream of the upper trough which coupled with upslope flow into the higher terrain should yield corridors of more focused lift.

The latest RAP analysis does show some elevated instability up across areas of northeast GA up through southwest NC with as much as 250 to 500 J/kg of MUCAPE. This alone coupled with the orographics will support efficient and rather shallow-top convection, and especially with the available moisture in the low to mid-levels of the column. As boundary layer heating increases, slight deeper convection will become possible.

Already radar shows some some linear convective structures across north-central GA that are lifting north-northeastward into the general vicinity of northeast GA, with some uptick in shower activity seen across upstate SC as well. The convective trends and latest hires model guidance suggests an uptick in rainfall rates in time, with potential for 1 to 2 inch/hour rainfall rates.

Overall, the highest rates in the near-term should be across north-central to northeast GA, but by mid-afternoon and beyond, the rates up across upstate SC and southwest NC should increase. Generally as much as 2 to 4 inches of additional rain are expected for this MPD valid time period which is consistent with the latest multi-model hires consensus.

Some urban flash flooding concerns will be possible in the near-term across north-central to northeast GA, but more terrain-focused impacts will gradually be possible this afternoon for upstate SC and southwest NC.