|Mesoscale Discussion 1361|
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Mesoscale Discussion 1361
NWS Storm Prediction Center Norman OK
1238 PM CDT Thu Jul 20 2017
Areas affected...Much of Vermont...New Hampshire...Maine...and far
Concerning...Severe potential...Watch unlikely
Valid 201738Z - 201945Z
Probability of Watch Issuance...20 percent
SUMMARY...Widely-scattered to scattered thunderstorms are expected
to increase in coverage the next few hours and will pose a threat
for brief severe wind gusts, but the isolated nature of the threat
is expected to preclude the need for a Watch.
DISCUSSION...Visible satellite imagery shows an expansive cumulus
field over the area with a few thunderstorms along the western edge
of this field over far northern Maine and far northwestern Vermont.
A 100-kt westerly upper level speed max currently overspreading NY
is contributing to forcing for ascent and is increasing the bulk 0-6
km vertical wind shear to 30-45 kt, supportive of some organized
convective structures. However, weak wind shear in low-levels, and
substantial dryness in mid-upper levels, also characterized by poor
lapse rates, should limit the severe potential. Nonetheless, steep
low-level lapse rates in regions that experience the strongest
heating could support brief severe wind gusts with the strongest
downdrafts. This threat should remain isolated enough to preclude
the need for a Watch.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 47226941 47266847 47026806 46366794 45576812 44606885
44076982 43807061 43547124 43407175 43407261 43687288
44167320 44707342 45077339 45567272 45887197 46267119
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