Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Memphis Tennessee
1234 am CDT Sat Jul 26 2014
Updated from the 06z aviation discussion
Previous discussion... /issued 822 PM CDT Friday Jul 25 2014/
updated for adjusting cloud cover and temperatures.
High level moisture continues to reside over the midsouth from
earlier convective activity in Illinois. Despite the clouds
temperatures have already fallen into the low 70s in the adjacent
Tennessee River counties. Have adjusted the evening forecast
accordingly with no other changes needed.
as of 3 PM...temperatures once again are quite comfortable...if
not abnormal...with readings in the low to middle 80s across the
middle-south this afternoon. Dewpoints are slowly on the rise
especially in areas west of the Mississippi River. Winds are light
and variable with mostly clear skies.
Short term...tonight into Monday morning...
tonight will be likely be a few degrees warmer than last night as
atmospheric moisture has slightly increased. Skies will be mostly
clear with light winds which will allow temperatures to drop into the
60s again areawide.
By tomorrow...summertime conditions appear to make a commanding
return as highs climb into the low to middle 90s. The upper level ridge
will build in nicely and return flow will setup across the region.
This will significantly increase both low level moisture and
temperatures for tomorrow. Heat indices will likely hit the triple
digit mark...but will remain below advisory criteria.
By Saturday night...an upper level trough will drop southeast
out of Manitoba Canada and into the upper Midwest. In
response...a shortwave trough will develop downstream from the
main trough and an mesoscale convective system will likely push through the upper
Mississippi Valley overnight. Models currently show the mesoscale convective system
possibly brushing up against the northern parts of the forecast area which
will likely trigger a few showers and thunderstorms. In
addition...the mesoscale convective system may eject a few boundaries on Sunday morning
across the aforementioned area.
By Sunday afternoon...a surface low will quickly traverse across the
Great Lakes and a trailing cold front will push into the middle-south
by Sunday evening. Ahead of the front...a moderately unstable
airmass will exist. SBCAPE values in excess of 2000 j/kg...lifted indice's
around -8 c...and middle level lapse rates around 7 c/km. In
addition...any left over boundaries from overnight convection may
be hanging around and act as a forcing mechanism for a few daytime
storms. There is still a little discrepancy with the amount of quantitative precipitation forecast
this front will generate...as the Euro continues to indicate none.
Nonetheless...the GFS and NAM are in good agreement that a few
strong to severe storms will be possible as the front pushes
through the mid-south. The main hazards will be damaging winds and
Long term...Monday through late next week...
a few lingering showers and thunderstorms will be possible in the
morning over north Mississippi as the main trough departs off to
the east. Cool Canadian high pressure will push in behind the
front for Tuesday and Wednesday. High temperatures will be in the
lower 80s with overnight lows in the lower 60s through at least
Thursday. Conditions appear to remain dry and temperatures are
expected to remain below normal through next weekend.
06z taf cycle
VFR conditions for forecast period with the exception of overnight
when some fog/mist will develops for a short period of time before
sunrise. Winds will increase on Saturday a little and should stay
up even into Saturday night. However...Tupelo the winds Saturday
evening will decrease...however...will not be calm. Tlsjr