084
AWUS01 KWNH 172031
FFGMPD
VAZ000-NCZ000-TNZ000-180130-

Mesoscale Precipitation Discussion 1030
NWS Weather Prediction Center College Park MD
431 PM EDT Tue Sep 17 2024

Areas affected...Piedmont to Southern Blue Ridge

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

Valid 172027Z - 180130Z

SUMMARY...East to West training and efficient rainfall rates up to
2-3"/hr in a band developing over an occluded front over the
Piedmont of northern North Carolina will continue to develop and
shift across portions of the southern Blue Ridge near the NC/VA
border into this evening. Localized flash flooding/rapid
inundation flooding in this narrow corridor is likely.

DISCUSSION...Convection has reinvigorated in broad convergence
along/north of an occluded front over the NC Piedmont this
afternoon from around the Raleigh-Durham Triangle west through the
southern Blue Ridge near the NC/VA border. Dewpoints in the low
70s with sufficient instability (1000 J/kg MUCAPE) along the
occluded front are fueling stronger updrafts and the influx of
tropical moisture is allowing redevelopment. PW of 1.6 to 1.8" are
1.5 sigma from normal support 2-2.5"/hr rain rates that may
locally peak at 3"/hr as seen from KFCX over Stokes Co NC,
particularly in areas of upslope with the steep eastern side of
the Blue Ridge (near and south of Fancy Gap) in the area of
concern.

Slow motion to the occluded low/front will support west to east
training over the next few hours. This may result in 3-5"
localized totals over the NC Piedmont and especially along the
Blue Ridge. Given that around an inch of rain fall in advance of
this activity over the past day, FFG is generally around 1.5"/hr.
Recent HRRR runs have picked up on this activity and features
splotches around 2" through 02Z. However, given the sufficient
instability, slow motion, and heavy rates observed, flash flooding
is considered likely.


Jackson

...Please see www.wpc.ncep.noaa.gov for graphic product...

ATTN...WFO...MRX...RAH...RNK...

ATTN...RFC...LMRFC...OHRFC...SERFC...NWC...

LAT...LON   36938152 36838049 36647977 36337900 36057852
            35827844 35757878 36218049 36398181