Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
638 PM EST Sat Nov 16 2019
 
Day 1
Valid 01Z Sun Nov 17 2019 - 12Z Sun Nov 17 2019 

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS COASTAL 
NORTH CAROLINA...

Coastal Carolinas...
While significant differences remain concerning where the heaviest 
rains will occur across eastern North Carolina into far southeast 
Virginia, there is a strong model signal for strengthening 
easterly low level flow to the north of the strengthening deep 
layer low off the Southeast/southern Mid-Atlantic coast.  The 
850-700mb moisture flux anomalies from the ECMWF, NAM, and GFS all 
show a west to east oriented moisture flux anomaly axis oriented 
across eastern NC.  Moisture flux anomalies reach 2.5 to 4 
standard deviations shortly within this axis and maintains this 
strength through Sunday morning.  Heavy rains are possible in this 
axis, with hi resolution model consensus and HREF mean showing 
precip totals of 2 to 5"+ across the far eastern portions of NC 
into far southeast VA, with potentially higher totals just 
offshore where the best instability, 500-1000 j/kg mu-cape, is 
forecast to be.  The global guidance remains drier than the 
mesoscale guidance, though there have been recent radar trends 
showing an advance of shower and thunderstorm activity towards 
southeast NC.  If the heavier qpf solutions do occur across the 
Outer Banks, flash flooding issues would be more urban rather than 
due to soil saturation.   Very heavy rains may occur in bands 
oriented southeast to northwest.  Hi res guidance is showing 
hourly rates of 1.5-2.5" affecting the Outer Banks, overnight into 
the morning hours.  These rains may produce localized runoff 
issues, ponding of water across paved surfaces.  A marginal risk 
area was drawn to encompass the model spread of where the heaviest 
hourly rates are forecast by the hi res guidance.

Roth/Chenard/Oravec
 
Day 1 threat area: www.wpc.ncep.noaa.gov/qpf/94epoints.txt