SPC MD 1620


MD 1620 Image

Mesoscale Discussion 1620
NWS Storm Prediction Center Norman OK
0156 PM CST Sun Nov 04 2018

Areas affected...southeastern Louisiana

Concerning...Severe potential...Watch unlikely 

Valid 041956Z - 042200Z

Probability of Watch Issuance...5 percent

SUMMARY...An isolated damaging-wind threat may evolve with storms
along a frontal boundary on the western fringes of the discussion
area.  A WW issuance is not anticipated at this time.

DISCUSSION...Recent satellite, radar, and lightning trends indicate
a consolidating and intensifying linear segment across
Ascension/Assumption Parishes in Louisiana at this time.  These
storms are in a destabilizing environment, with upper 70s F surface
temperatures and mid 60s F dewpoints contributing to 1000-1500 J/kg
MUCAPE within the pre-convective environment just ahead of the
storms.  Frontal forcing and continued destabilization will continue
to support forward propagation over the next couple of hours, with
at least a marginal/isolated risk of damaging winds expected over
the next hour or so.

It is uncertain how far east the threat with these storms will
persist.  Larger-scale forcing for ascent (associated with a
shortwave centered over the ArkLaTex) will shift northeastward away
from the region over time, which may lead to a weakening trend
despite ongoing destabilization and continued forcing from
frontal/outflow mechanisms.  As long as storms persist, a low-end
damaging wind threat will also exist, with storms migrating toward
the New Orleans Metro area through 21-22Z.

..Cook.. 11/04/2018

...Please see www.spc.noaa.gov for graphic product...


LAT...LON   30329053 30358992 30298938 30118907 29798906 29188966
            29139005 29189069 29439123 29859126 30189090 30329053 

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