Mesoscale Precipitation Discussion 0683
NWS Weather Prediction Center College Park MD
1135 PM EDT Sun Jul 09 2023

Areas affected...Northeast Upstate NY...VT...Ext Western
NH...Western MA...

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

Valid 100335Z - 100915Z

SUMMARY...Spotty slow moving embedded showers/thunderstorms may
train within the deformation zone may train resulting in scattered
spots resulting in low-end possible flash flooding. 

DISCUSSION...Reducing pockets of instability are maintaining
scattered thunderstorms mainly along the north NH/VT border and
western WA, though these are expected to fade over the next hour
or so with spots of 1-2" possible.  However, synoptic forcing is
starting to strengthen and strong moisture convergence along an
850-700 deformation zone will start to spark shallow emebedded
showers/thunderstorms across E NY and portions of VT over the next
few hours.  RADAR moasic shows a shearing warm conveyor belt
shortwave lifting across Delaware into Schoharie county and is
generally associated with a developing 850 to 700 mb low.

A speed convergence deformation zone will sharpen downstream
across the Northern Hudson Valley toward NW VT. Still 850-700mb
WAA remains strong from the south and southeast with 15-25kts
transporting 1.75" and weak 100-250 J/kg of MUCAPE.  The
convergence should support shallow thunderstorms along and east of
the deformation zone with rates of 1"-1.25"/hr.  Given deep layer
flow, there may be some training elements particularly after 06z,
when WAA convergence appears to maximize.  As such, spots of
1.5-2.5" totals are possible.  This is low-end rainfall totals
relative to the FFG values in the region but an isolated flash
flood will remain possible, though the broad area of moderate
rainfall with spotty totals around 2" should at least maintain
higher streamflow for creeks and streams across the area.

Gallina

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

ATTN...RFC...NERFC...NWC...

LAT...LON   45117265 45067184 45007133 44357150 43607203
            42177280 42477448 43477421 44337379 45017338