309
AWUS01 KWNH 071101
FFGMPD
MAZ000-NHZ000-VTZ000-CTZ000-NYZ000-NJZ000-PAZ000-071600-

Mesoscale Precipitation Discussion 0392
NWS Weather Prediction Center College Park MD
701 AM EDT Sat Jun 07 2025

Areas affected...Northeast PA...Central and Eastern NY...Central
and Southern New England

Concerning...Heavy rainfall...Flash flooding likely

Valid 071100Z - 071600Z

SUMMARY...Broken areas of heavy showers and a few thunderstorms
will continue through the morning hours across areas of northeast
PA into eastern NY, and eventually spreading into parts of central
and southern New England toward midday. Additional areas of flash
flooding are likely given locally sensitive antecedent conditions.

DISCUSSION...Recent cloud-top cooling is noted with a broken area
of heavy showers and a few thunderstorms impacting areas of
northeast PA into central and eastern NY. The activity is being
focused by a shortwave impulse advancing into the Northeast out
ahead a larger scale trough lifting through the OH Valley and
central Appalachians. This energy is also interacting with a
quasi-stationary front and helping to focus a wave of low pressure
which is promoting isentropic ascent and frontogenetical forcing
near the front for the locally heavier and concentrated areas of
rainfall.

Despite very modest instability profiles with only about 250 to
500 J/kg of MUCAPE value, the vertical column is quite moist with
PWs running a solid 1.5 standard deviations above normal, and
CIRA-ALPW data showing strong concentrations of mid-level
moisture. The recent cloud-top cooling suggests the current
activity will likely continue in the near-term, and the latest
upper-air analysis is showing some improving right-entrance region
upper-jet dynamics over the region for ascent. This will
compensate for the lack of instability over the next few hours and
continue to favor at least broken ares of highly efficient
rainfall and elevated rain rates.

Rainfall rates may reach as high as 1.5 inches/hour with the
strong convective cores, and with relatively slow cell-motions,
some short-term rainfall rates at least by late-morning may reach
2 to 3+ inches. While the activity over the next few hours will
tend to be more focused over areas of eastern NY and down into the
Poconos of northeast PA, areas of central and southern New England
will also begin to see a threat of heavy rainfall by midday.

The antecedent conditions in general across the region are rather
sensitive, with locally elevated streamflows, and thus with the
additional rainfall this morning, there will likely be concerns
additional areas of flash flooding.

Orrison

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

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

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

LAT...LON   43717394 43387208 42417198 41757275 41277372
            41067522 41777632 42897584