242
AWUS01 KWNH 061722
FFGMPD
MEZ000-MAZ000-NHZ000-VTZ000-CTZ000-NYZ000-NJZ000-PAZ000-062320-

Mesoscale Precipitation Discussion 0381
NWS Weather Prediction Center College Park MD
121 PM EDT Fri Jun 06 2025

Areas affected...Much of Central and Eastern NY...Central and
Southern New England

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

Valid 061720Z - 062320Z

SUMMARY...Showers and thunderstorms with heavy rainfall rates will
expand in coverage this afternoon across especially central and
eastern NY through much of central and southern New England.
Scattered areas of flash flooding are likely, some of which may be
locally significant.

DISCUSSION...The midday GOES-E visible satellite imagery shows
cloud cover and showers advancing across areas of central NY in
association with a shortwave impulse. This energy coupled with
proximity of quasi-stationary front and a destabilizing boundary
layer along it will promote developing and expanding coverage of
heavy showers and thunderstorms this afternoon across much of
eastern New York through central and southern New England.

MLCAPE values have risen to as much as 1000 to 2000+ J/kg across
southeast NY through central and western CT, and also up across
central and western MA. A nose of lesser instability is focused
north of here up across southern VT/NH as well. Additional
destabilization is expected over the next couple of hours as
strong diurnal heating continues ahead of the approaching upstream
energy. This warm sector airmass is also quite moist with PWs of
1.5 to 1.6+ inches in place, and this pooling of moisture will be
supported through the afternoon by a gradual increase in southwest
low-level flow ahead of the shortwave impulse and as a wave of low
pressure develops and transits the front across the interior of
the Northeast.

The 12Z HREF and 06Z REFS guidance supports locally very heavy
rainfall rates reaching upwards of 2 inches/hour, and with
convection also become locally concentrated/focused near some of
the higher terrain of central and southern New England and
especially southern VT, southern NH, and western and central MA.
Some portions of southwest ME also based on recent HRRR guidance
gets into some locally stronger concentrations of convection by
early this evening as well.

Given the approaching upstream wave and level moisture and
instability that is in place, broken coverage of heavy showers and
thunderstorms are likely with high rainfall rates that will be
capable of some cell-training. As much as 3 to 5+ inches will be
possible near some of the orographically favored terrain including
the southern portions of the Green and White Mountains on down
into the Worcester Hills and Berkshires. Elsewhere, areas away
from the terrain and back into areas of eastern NY including the
Hudson Valley and adjacent Catskills may see as much as 2 to 4
inches of rain where storms become locally focused.

Given the overall setup, and the relatively moist antecedent
conditions, these rains are likely to cause flash flooding by
later this afternoon which will likely continue into a part of the
early evening time frame. Some locally significant flash flooding
will be possible where the heaviest totals focus near areas of
higher terrain.

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   44777023 44316968 43836979 43477027 42487119
            41747225 41257376 41317472 41807536 42317540
            43007489 43387466 43967447 44287353 44377242
            44667142