740
AWUS01 KWNH 142010
FFGMPD
MEZ000-MAZ000-NHZ000-VTZ000-CTZ000-NYZ000-150209-

Mesoscale Precipitation Discussion 0687
NWS Weather Prediction Center College Park MD
410 PM EDT Mon Jul 14 2025

Areas affected...New England

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

Valid 142009Z - 150209Z

SUMMARY...Scattered flash flood concerns across New England ahead
of a slow-moving cold front to the northwest.

DISCUSSION...Current radar and satellite composite note a
generally scattered convective development across New England with
a few stronger cores located over northern New England and over
interior southern New England. A cold front to the northwest over
eastern Canada continues to slowly migrate eastward with ample
deep layer moisture and instability located downstream over the
northeast CONUS as evident by an 18z KGYX sounding of 1.98" PWATs,
a daily record for the site. Sufficient boundary layer buoyancy
across New England will allow for a suitable thermodynamic posture
leading to multiple pulse and multi-cell clusters to materialize
over the rest of the afternoon and early evening.

Relative storm motions are mostly progressive north of I-90,
however as noted via the 18z sounding out of KGYX, Corfidi upshear
vector notes a much slower mean motion between 10-15kts which can
be exhibited when assessing the broad convective regime already in
place. Pockets of locally heavy rainfall can be seen migrating at
a slower pace with some anchoring along the terrain encompassing
interior New England. This could lead to enhanced heavy rain
prospects with rates between 1-2"/hr over the span of a few hours
within complex terrain located over VT/NH into western ME.
Historically, this is when flash flood concerns become more
notable, especially within environments exhibiting deep layer
moisture of this magnitude and an increasingly uni-directional
deep layer wind.

Recent HRRR output has areas across southwest ME into northern New
England as the primary area of focus with some ongoing stronger
cores across CT/MA likely to continue for at least a few more
hours as they shuffle eastward.

More scattered nature of cells and faster mean cell motions
overall should limit more significant flash flood prospects, but
current scenario is feasible for isolated to widely scattered
flash flooding leading to more "possible" wording for this
issuance.

Kleebauer

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

ATTN...WFO...ALY...BOX...BTV...CAR...GYX...

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

LAT...LON   45857039 45856995 45646954 45326941 44856968
            44386989 44056999 43717027 43407058 43007075
            42627100 42267149 42007184 41897202 41787229
            41857264 41997294 42307307 42897326 43327342
            43707348 44087341 44437322 44697288 45037216
            45237159 45417094 45617073