Subj : Heavy Rain/Flooding NC/SC To : All From : Dumas Walker Date : Fri Jul 26 2024 09:24 am AWUS01 KWNH 261353 FFGMPD NCZ000-SCZ000-261852- Mesoscale Precipitation Discussion 0734 NWS Weather Prediction Center College Park MD 953 AM EDT Fri Jul 26 2024 Areas affected...South-Central to Southeast NC...North-Central to Northeast SC Concerning...Heavy rainfall...Flash flooding possible Valid 261352Z - 261852Z SUMMARY...Slow-moving and very efficient convection with high rainfall rates will be impacting areas of south-central NC into north-central and northeast SC going through midday. Eventually areas of southeast NC will also get into some of this activity this afternoon. Some flash flooding is possible. DISCUSSION...A very small-scale low-level circulation and associated vort center is situated near the NC/SC border region which is yielding some low-topped and extremely efficient convection across areas of south-central NC and especially areas of north-central SC. There is also evidence of a surface trough axis extending eastward ahead of the weak low down across northeast SC and some adjacent areas of southeast NC. At least modest, but persistent moisture convergence along this trough axis ahead of the low center along with a gradual increase in boundary layer instability via the diurnal heating cycle should facilitate a persistence and localized expansion of convection going through the early afternoon hours. There is already a bit of an instability gradient oriented in close proximity to this trough from northeast SC into southeast NC where MLCAPE values are as high as 1000+ J/kg. The 12Z RAOB data from CHS and ILM show a deep tropical environment with tall/skinny CAPE profiles. This will strongly support a highly efficient warm rain set-up for very heavy rainfall rates that will be capable of reaching 2 to 3 inches/hour. Outside of the recent HRRR guidance, the early morning guidance is not exactly handling the ongoing activity particularly well. However, with the current radar and satellite trends, and slow cell-motions/efficient rainfall set-up, some localized storm totals reaching 3 to 5 inches will be possible going through early this afternoon. Some areas of flash flooding will be possible as a result, and especially with some areas already seeing moist antecedent conditions. Orrison ATTN...WFO...CAE...GSP...ILM...RAH... ATTN...RFC...SERFC...NWC... LAT...LON 35207976 35067890 34547870 34237946 34268042 34588086 34908083 35118045 --- SBBSecho 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (21:1/175) .