309
AWUS01 KWNH 140016
FFGMPD
VTZ000-NYZ000-NJZ000-PAZ000-MDZ000-VAZ000-DCZ000-WVZ000-140613-

Mesoscale Precipitation Discussion 0676
NWS Weather Prediction Center College Park MD
813 PM EDT Sun Jul 13 2025

Areas affected...Portions of the Central
Appalachians...Mid-Atlantic into the Northeast

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

Valid 140013Z - 140613Z

SUMMARY...Scattered areas of heavy showers and thunderstorms will
continue through the remainder of the evening and parts of the
overnight period. Isolated to scattered areas of flash flooding
will remain possible with some of the stronger storms given high
rainfall rates.

DISCUSSION...The early evening GOES-E IR satellite imagery shows a
few broken clusters of heavy shower and thunderstorm activity
continuing to impact portions of eastern WV and western VA up
through central PA and through central/eastern NY and northern VT.
This elongated axis of lingering convection is being highly driven
by a combination of orographics/terrain-forcing and lingering
instability with MLCAPE values still of 1500 to 2000+ J/kg.
Additionally, the activity up PA/NY and VT is being aided by some
very modest shear associated with some weak shortwave energy
arriving from the Upper OH Valley and Lower Great Lakes region.

A corridor of favorable moisture convergence is seen lingering up
across areas of western VA through central PA and into southern
and eastern NY in particular, and this may allow for some of the
ongoing convection to linger over the next several hours, and
especially with localized upslope flow near the terrain and the
aforementioned pool of instability.

The last few runs of the HRRR/RRFS and the 18Z HREF guidance
suggest additional areas of convection going through the remainder
of the evening hours will be capable of producing rainfall rates
of 1 to 2 inches/hour. This is highly supported by the latest
CIRA-ALPW data which shows deep concentrations tropical
moisture/high PWs across the central Appalachians, Mid-Atlantic
and interior of the Northeast.

Some additional spotty 2 to 4 inch rainfall amounts will be
possible going through midnight. This coupled with locally wet
antecedent conditions will support a threat for some additional
isolated areas of flash flooding.

Orrison

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

ATTN...WFO...AKQ...ALY...BGM...BTV...CTP...LWX...OKX...PBZ...
PHI...RLX...RNK...

ATTN...RFC...ALR...RHA...TAR...TIR...NWC...

LAT...LON   45157252 44877185 43627260 42027431 40657530
            39117687 37527816 36927916 37157999 38377978
            40197851 41837751 42617651 43147559 44447414
            44927346