Mesoscale Precipitation Discussion 0950
NWS Weather Prediction Center College Park MD
536 PM EDT Wed Aug 05 2026

Areas affected...eastern PA into central/northern NY and the NYC
metro

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

Valid 052131Z - 060200Z

SUMMARY...A localized flash flood threat will remain for another
2-4 hours across portions of eastern PA into central/northern NY
and the NYC metro. High sub-hourly rainfall rates will support the
potential for 1 to 2+ inches through 02Z.

DISCUSSION...Radar imagery at 2115Z continued to show scattered
showers/thunderstorms extending from portions of southeastern PA
into north-central NJ, although the intensity of rainfall has
lowered compared to earlier this afternoon. Visible satellite
imagery showed a number of low level vorticity maxima embedded
within a broader axis of low level convergence that extended from
the east-central MD/PA border into central NJ, each associated
with locally heavier regions of rainfall. MLCAPE has been limited
to ~500 to 1000 J/kg along this convergence axis, but instability
has also been advecting northward in association with a weak warm
front, with PWs locally in excess of 2 inches.

While the threat for additional flash flooding appears isolated
through the evening, as the diffuse warm front continues to lift
north, weak instability (<1000 J/kg) is forecast by the RAP to
expand into northeastern PA, northern NJ and the NYC metro. Based
on earlier rainfall rates across PA into NJ, the potential will
exist for 15-minute rainfall totals of 0.5 to 1.0 inches and storm
totals of 1 to 2+ inches. Should these higher rates materialize,
heavy rainfall should remain isolated across eastern PA into
northern NJ and southern NY, but overlap with urban or otherwise
sensitive locations could result in flash flooding.

Otto

ATTN...WFO...BGM...CTP...LWX...OKX...PHI...

ATTN...RFC...RHA...TAR...NWC...

LAT...LON   41577437 41257376 40727369 40147470 39647646
            39937719 40557695 41067605 41517526