Mesoscale Precipitation Discussion 0333
NWS Weather Prediction Center College Park MD
725 PM EDT Thu May 29 2025

Areas affected...Central NC

Concerning...Heavy rainfall...Flash flooding likely

Valid 292325Z - 300225Z

SUMMARY...Heavy showers and thunderstorms across central NC will
continue through the mid to late-evening hours. Areas of flash
flooding are likely and especially around the Raleigh-Durham
metropolitan area and adjacent suburbs over the next couple of
hours.

DISCUSSION...Radar imagery shows showers and thunderstorms with
heavy rainfall rates of 1.5 to 2.0 inches/hour impacting central
NC as a shortwave impulse lifting up across the Southeast U.S.
coastal plain interacts with a moist and unstable airmass pooled
across the region.

MUCAPE values are still locally on the order of 1000+ J/kg, and
there are multiple small-scale outflow boundaries interacting with
each other that are resulting in pockets of enhanced low-level
convergence for additional convective development. The airmass is
moist with PWs of near 1.5 inches, and this coupled with the
remaining instability should still favor locally enhanced rainfall
rates over the next couple of hours.

There is also proximity of a warm front across central NC along
with some modest right-entrance region upper-level jet dynamics
that are helping to further facilitate the sustenance of
convection at least in the near-term. Given the high rainfall
rates and some cell-merger activity, expect some additional spotty
rainfall amounts of 2 to 4 inches before sufficient boundary layer
stabilization occurs for the activity to weaken later this evening.

Areas of urban flash flooding are locally already occurring and
will continue through the mid to late-evening hours givenj the
high rainfall rates. This will include a near-term threat to the
Raleigh-Durham metropolitan area which currently has heavy shower
and thunderstorm activity situated to the west and south of the
city.

Orrison

ATTN...WFO...GSP...RAH...RNK...

ATTN...RFC...ALR...NWC...

LAT...LON   36507820 36287765 35847759 35507790 35327857
            35338008 35838044 36347951