Mesoscale Precipitation Discussion 0653
NWS Weather Prediction Center College Park MD
423 PM EDT Mon Aug 13 2018

Areas affected...West Virginia...Ext Eastern Ohio...Northwestern
VA

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

Valid 132022Z - 140100Z

SUMMARY...Convection organizing loosely along outflow boundaries
seeking out remaining instability.  Some occasional  orientation
to the mean flow may support some repeat cells.  Flash flooding
remains possible through until nightfall.

DISCUSSION...Ongoing convection beginning to organize a bit better
along outflows, particularly from Ohio county, WV to Monongalia
county and from Wood, WV to Kanawha, WV. As the outflow propagates
southward slowly, the mean cloud bearing flow is starting to
strengthen ever so slightly and orient favorably to these arcs of
convection suggesting mean cell motions as jet core rounds the
base of the compact upper low in S WV, shifting the center more
northeastward toward Garrett county, MD.  CIRA Layered PWATs
confirmed by the RAP, suggest mid-level moistening across SW PA
into N WV, while ahead and south of the lines, instability remains
sufficient for continued convective development, generally 1500
J/kg MLCAPEs near CRW and more in the 750-1000 J/kg range near the
PA/WV line.  This should support continued 1-2" totals in short
duration, and now with some potential occasional repeats, totals
up to 2.5" are possible keeping flash flooding a risk through the
next 3-4 hours before instability is exhausted/diminished due to
loss of solar radiation.  

Gallina

ATTN...WFO...LWX...PBZ...RLX...RNK...

ATTN...RFC...MARFC...OHRFC...

LAT...LON   40798081 40638047 40208032 39848017 39557952
            39507935 39367895 39237840 39047817 38757818
            38447837 37807898 37867965 37438048 37408106
            37598161 37898186 38228192 38788194 39408173
            40158141