Mesoscale Discussion 1924
NWS Storm Prediction Center Norman OK
1019 AM CDT Wed Sep 04 2019
Areas affected...Portions of Central/Eastern NY...VT...NH...Western
ME...MA...CT...and Far Northeast PA
Concerning...Severe potential...Watch likely
Valid 041519Z - 041715Z
Probability of Watch Issuance...80 percent
SUMMARY...Increasing thunderstorm coverage is anticipated over the
next several hours. Damaging wind gusts are the primary severe
threat but a couple tornadoes are also possible. A watch will
eventually be needed for portions of the region.
DISCUSSION...Recent surface analysis places a cold front from SLK
(in far northern NY) southwestward across central NY to just east of
BFD (in far north-central PA). Radar trends have shown gradually
increasing intensity of the cells along the front in south-central
NY as they move into a diurnally destabilizing and modestly buoyant
air mass downstream. Ongoing moisture advection has lead to an 2-4
degree increase in dewpoints downstream across the Hudson Valley and
this general trends is expected to continue, leading to air-mass
destabilization ahead of the front as far north as northeast NY, VT,
NH, and western ME.
At the same time, strengthening large-scale forcing for ascent
attendant to the shortwave trough moving into the Northeast will
augment the frontal forcing already occurring. The combination of
this increased forcing for ascent and air-mass destabilization is
expected to result in expanding thunderstorm coverage over the next
few hours. Even with the modest buoyancy, strong vertical shear will
provide a kinematic environment supportive of organized storms.
Primary threat will be damaging wind gusts associated with bowing
line segments. However, given the southerly flow across southeastern
NY and southern New England, some tornado threat also exists,
especially with any more discrete cells ahead of the front. A watch
will likely be needed by early afternoon, particularly over eastern
NY and New England.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 41747693 42387681 43827469 44847352 44597056 42547148
41537287 41317494 41747693