Area Forecast Discussion
Issued by NWS Memphis, TN
FXUS64 KMEG 301135
Area Forecast Discussion
National Weather Service Memphis TN
635 AM CDT SAT JUL 30 2016
Update for the 12Z Aviation Discussion
.PREV DISCUSSION... /issued 303 AM CDT SAT JUL 30 2016/
The subtropical ridge remains centered over the southwest CONUS
this morning, with a broad trough over the east. Northwest flow
aloft over the Plains will continue to provide a steady diet of
weak shortwave troughs for the Mid-South this weekend. This will
result in mostly cloudy skies and scattered showers and
thunderstorms, especially during the afternoon and evening hours.
The primary forecast challenge for the weekend will be timing
individual shortwave troughs. As these waves approach, we`ll see
an uptick in convective coverage. The strongest forcing will
remain to our north in the westerlies, but we should see some
influence from these systems in the coming days. Temperatures
in the upper 80s and lower 90s this afternoon will support MLCAPEs
of 1500-2000 J/kg, but deep layer shear will be lacking for
organized updrafts. However, a pulse storm or two will still be
capable of producing wet microbursts.
We will see a slight increase in column moisture today, with
precipitable water values generally at or above 1.75". As we`ve
seen the past few days, slow moving thunderstorms will be capable
of producing locally heavy rainfall in a very short period of
time. The scenario for Sunday is very similar, with rain chances
again coming down to about a 50/50 shot for any particular point
in the CWA.
The subtropical ridge will expand early next week, building a bit
farther north and east. While subsidence associate with the ridge
should limit the coverage of diurnal convection, we do anticipate
sufficient moisture to maintain 20-30% PoPs for much of the week.
We will, however, experience an increase in surface temperatures.
Afternoon highs will gradually climb into the mid 90s by Tuesday,
remaining slightly above climo through the remainder of the week.
Corresponding heat indices will approach 105 degrees in some areas
Tuesday through Thursday. Expect overnight low temperatures
generally in the mid 70s.
12Z TAF cycle
Some low clouds are currently over portions of West Tennessee this
morning which should lift up in a few hours. Scattered showers and
thunderstorms are just north and west of the Memphis area.
Additional thunderstorms are expected to develop this afternoon
and continue into the evening hours. Some patchy fog may develop
overnight. Winds will be light and mainly from the southwest for
much of the forecast period.