Scientific Forecaster Discussion
fxus64 kmeg 171129
Area forecast discussion
National Weather Service Memphis Tennessee
629 am CDT Sat Aug 17 2019
updated for 12z aviation discussion.
Previous discussion... /issued 401 am CDT Sat Aug 17 2019/
Currently...weak zonal flow aloft prevails across the mid-south
with the storm track north of the region. Skies are clear across
the mid-south with light winds and mild temps ranging from the
upper 60s near the Tennessee River to upper 70s in Memphis.
Today through Sunday...weak zonal flow aloft will continue with
southerly winds at the surface slowly ratcheting up the humidity
levels. Expect highs in the mid 90s with dewpoints in the lower 70s
across the Delta. Heat index values will range from 100 to 105
across the Delta. Right now it appears that the heat index will
stay below 105f at most locations so will hold off on an
advisory. Storm track will remain north of the area today and
tonight. Humidity levels will further increase on Sunday with
more areas hitting heat index values of 105f or more. An advisory
may be needed for areas south and west of Memphis. A weak
disturbance may result in a few afternoon showers and
thunderstorms in parts of the Delta on Sunday.
Monday through and Tuesday...upper level high pressure will build
over the Southern Plains and edge into the region. Hot and
increasingly humid weather will continue to spread across the area
with surface dewpoints in the mid to occasionally upper 70s. As a
result expect afternoon heat index values to hit 105f or greater.
Heat advisories will likely be needed for much of the area.
Increasing humidity will lead to isolated to scattered diurnal
convection both days.
Wednesday through Friday...a mid level trough will move through
the Great Lakes during the Wed/Thu time frame and push a cold
front south into the region resulting in increased
shower/thunderstorm coverage. The front will stall out across the
region through the end of the week providing a focus for showers
and thunderstorms...especially during the afternoon and evenings.
Wednesday will still be quite hot with some areas south and west
of Memphis still hitting 105f heat index readings. Clouds and
precip should knock down temps Thu and Fri...at least below heat
VFR conditions are expected through the taf period with high
pressure over the region. Winds will remain light from the S/SW.
Mostly clear skies and dry conditions are forecast.