Mesoscale Precipitation Discussion 0599
NWS Weather Prediction Center College Park MD
203 AM EDT Sun Jul 06 2025

Areas affected...coast of northern SC/southern NC

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

Valid 060602Z - 061200Z

SUMMARY...Heavy rain and localized flash flooding will be possible
across coastal locations of the Carolinas as T.S. Chantal
approaches the northern SC coast tonight. Rainfall rates from 1 to
3 in/hr will be possible along with localized 2-4 inch totals
through 12Z.

DISCUSSION...T.S. Chantal was located about 35 miles SSE of Myrtle
Beach, SC via the latest NHC advisory from 06Z and was moving
toward the NNW at 7 kt. Recent GOES East infrared satellite
imagery showed the bulk of convection located in its front-right
quadrant due to a combination of southerly shear and dry air south
of the surface circulation as noted on layered PW imagery. After a
burst in colder cloud tops contained within the CDO from late
Saturday evening into the early overnight, there has been some
minor warming of cloud tops since 05Z from the center of the CDO
but recent cooling to the northeast. Local radar imagery from KTLX
showed outer bands moving across the northern SC and southern NC
coast along with a core of slower moving heavy rain about 25 miles
southeast of Myrtle Beach. A curved rain band was becoming better
defined to the south of Cape Fear as Chantal's CDO edges closer to
the coast, tied to the recent cloud top cooling northeast of the
CDO.

Increasing rounds of steady heavy rain associated with Chantal are
expected to begin moving onshore near the SC/NC border over the
next 1-3 hours with increasing potential for 1-2 inches of rain in
30-60 minutes. Rain rates, perhaps as high as 2-3 in/hr, will be
possible with slow movement of Chantal's inner core and/or with
training from spiral banding to the northeast of the CDO as
banding interacts with the coast.

While only a small section of southern NC has received above
average rainfall over the past week, the rest of the region has
been relatively dry and therefore, much of the Coastal Plain of
northern SC/southern NC has relatively high flash flood guidance
values of 3+ inches in 3 hours. Given antecedent conditions, flash
flood potential due to incoming rounds of heavy rainfall appears
most likely across urban locations within the Coastal Plain from
Myrtle Beach to Wilmington, where potential for 2 to 4 inches of
rain will exist through ~12Z.

Otto

ATTN...WFO...ILM...MHX...RAH...

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

LAT...LON   34927824 34927783 34667737 34407730 34097742
            33727777 33317850 33097903 33177936 33757957
            34297935 34777874