Mesoscale Precipitation Discussion 0592
NWS Weather Prediction Center College Park MD
147 PM EDT Fri Aug 03 2018

Areas affected...Central to Eastern PA...Upstate NY...Western
MA...Southern VT and NH

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

Valid 031745Z - 032345Z

Summary...Slow-moving, training precipitation is expected to
continue to spread to the northeast, producing additional heavy
amounts.

Discussion...Morning soundings at PIT and ALY showed deep
saturation through the low to mid levels, with tall skinny CAPEs -
supporting efficient rainfall processes.  Observations from
central PA have shown the potential for some of these ongoing
storms to quickly produce heavy amounts.  Deep southerly inflow
ahead of a slow-moving trough will continue to support an
anomalous moisture plume.  This moisture along with strengthening
dynamics afforded by mid-level energy and favorable upper jet
forcing, in addition to increasing instability, is expected to
support an expanding axis of training precipitation.  This may
produce additional moderate to heavy amounts within the
highlighted region.  Neighborhood probabilities from the 12 UTC
HREF Mean show a significant signal for additional amounts of
2-inches or more through 00 UTC Sat within this region.  These
amounts may cause hydrologic concerns, especially across portions
of central to northeastern PA and the Catskill region in Upstate
NY, where flash flood guidance values are quite low from recent
heavy rains.

Pereira    

ATTN...WFO...ALY...BGM...BOX...BTV...CTP...GYX...PHI...

ATTN...RFC...MARFC...NERFC...

LAT...LON   43457236 43177192 42657230 42257324 41667458
            40787624 39877803 40167853 40987780 41517716
            42057621 42607508 43157344