Mesoscale Precipitation Discussion 0559
NWS Weather Prediction Center College Park MD
855 PM EDT Sun Jul 29 2018

Areas affected...Portions of central and eastern NC/SC

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

Valid 300100Z - 300500Z

SUMMARY...Scattered convection moving slowly in a high moisture
environment could produce hourly rainfall rates in excess of 2.00
inches during the evening hours. This much rainfall could pose a
flash flood threat over areas that saw heavy rainfall earlier this
weekend.

DISCUSSION...Regional radars and the most recent GOES-16 clean IR
loop showed that the convection extending from southern SC into
portions of central and eastern NC early this evening. While there
is still an axis of 1000-1500 J/KG of MLCAPE (these values are
confirmed by nearby 30/00z) near a stationary front extending from
east central GA into northeast NC, CIN is beginning extend across
the region, so a slow dissipation of convection can be expected
into the evening hours.

Much of the high resolution guidance showed instability remaining
in place through about 03/04z, though it becomes more separated
with time. However, with deep moisture remaining in place (with
precipitable water values in excess of 2.00 inches), and the low
level southerly inflow increasing, moisture will not be an issue
for a continued flash flood threat. The front could act as a focus
for scattered convection through about 30/04z.

Newer convection developing in the southerly flow is starting to
increase on regional radar, and IR tops are starting to cool. This
training, even if it remains scattered, while pose a flash flood
threat.

The most recent HRRR showed localized rainfall amounts near 6.00
inches over east central NC, as well as portions of south central
SC. These amounts could only occur with short term training or
cell mergers, which are possible given the current environment.
Since portions of the areas have seen 3.00 to 5.00+ inch rainfall
amounts over the past two days, any storm with producing hourly
rainfall rates near 2.00 inches will pose a flash flood threat
this evening.

Hayes

ATTN...WFO...AKQ...CAE...CHS...GSP...ILM...MHX...RAH...

ATTN...RFC...SERFC...

LAT...LON   36227614 34437803 32828084 33498156 35548040
            36197872