Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Memphis Tennessee
357 PM CDT Wednesday Oct 1 2014
As of 3pm scattered showers and thunderstorms are affecting
northeastern Arkansas and counties along the Mississippi River as the
surface high that was over the region yesterday has shifted east
allowing the atmosphere to become more conducive for these type
of storms. Temperatures were on track to be a few degrees warmer
than yesterday but cloud coverage has restricted readings to the
upper 80s in the areas near the thunderstorm activity. Showers and
storms will begin to subside as we lose daytime heating this evening.
Showers and thunderstorms will become possible once again along
and west of the Mississippi River as southerly flow increases and
warm...moist air advects into the area from the Gulf of Mexico
ahead of an approaching surface cold front associated with an
upper level trough that continues to push east out of the plains.
The prefrontal airmass will be moderately unstable with dewpoints
near 70 degrees and cape values ranging from 1500-2500 j/kg. Even
though some strong storms are possible ahead of of the front...the
best chances of severe weather will lie within a squall line that
forms along the frontal boundary as it progresses through northeast
Arkansas...the Missouri boothheel... northwest Mississippi... and
extreme west Tennessee. The primary threat with these storms will
be severe straight line winds with a secondary threat of large
hail. Forecast soundings depict a tall skinny cape profile with
the wbz heights around 13k feet and the -20 heights at near 25k
feet. Localized flooding is also possible but widespread flooding
will be unlikely due to the fast moving nature of this system.
Skies will clear quickly and cooler...drier air will begin to
filter in behind the front. Temperatures on Friday... Saturday... and
Sunday will be below normal with lows in the 40s Friday and
Saturday night. Another cold front will move through the midsouth
late Monday into Tuesday providing another chance at rainfall but
models still Haven/T come into agreement enough for significant
probability of precipitation.
18z taf cycle
MVFR conditions may develop at jbr between 02/13-17z.
Otherwise...VFR conditions will prevail through much of the
period. Light southeast/S winds will increase to 8-11 kts by Thursday
morning with vcsh possible. Better chances for rain showers/thunderstorms and rain mainly
Thursday afternoon/Thursday night.