Heat in Missouri, August 15, 2025

Area Forecast Discussion
National Weather Service Memphis TN
1151 AM CDT Fri Aug 15 2025

...New DISCUSSION, AVIATION, FIRE WEATHER...

.KEY MESSAGES...
Updated at 1151 AM CDT Fri Aug 15 2025

- Hot and humid conditions continue across the Mid-South. High
  temperatures will generally be in the mid 90s today, increasing
  to the upper 90s this weekend.

- A Heat Advisory is in effect both today and tomorrow for
  portions of the Mid-South from 11AM to 7PM.

- Most of the area will remain dry, but there is a 20 to 30
  percent chance of showers and thunderstorms for north
  Mississippi this afternoon.

&&

.DISCUSSION...
(This afternoon through next Thursday)
Issued at 1151 AM CDT Fri Aug 15 2025

It has been a persistence forecast of mid 90s temperatures with
afternoon showers and thunderstorms for the last week or so, and
that continues today. We're still in a dominant ridging pattern,
which is the culprit of the late summer heat. Southerly winds at
the surface have added Gulf Coast moisture to the equation, which
is causing humidity to soar and thus warranting a Heat Advisory
for much of the area, specifically along and west of the
Mississippi River. Expect 105+ heat indices in the advisory area
through 7PM tonight. Tomorrow will be a very similar story,
though the area of the Heat Advisory has been expanded by a few
counties.

As we move into the weekend pattern, the upper level ridge
amplifies just a little further and spreads out over the CONUS.
This will nudge temperatures into the upper 90s starting this
weekend. Looks like the ridge will reach its peak intensity by
Tuesday. Despite the increase in temperature, dewpoints actually
look a little lower so the apparent T remains largely the same as
we have seen over the past few days. More heat headlines will
likely be needed going into the weekend through at least midweek,
but small scale discrepancies in dewpoints are hard to resolve
this far out so these will be issued on a day-to-day basis.

In the extended forecast, the midlevel ridge retrogrades back to
the Four Corners region and amplifies again to 596 dam. This will
put us back in northwesterly flow by Thursday, sending the late
summer heat back down to more seasonable levels. Looks like we
should be done with heat headlines (for now) by Wednesday of next
week. Next Thursday and Friday look more pleasant with heat
indices topping out in the mid 90s. With each day this forecast
period, afternoon convection will be so isolated and PoPs so low
(20% or less) that most areas will not receive any precip or
respite from the heat.

&&

.AVIATION...
(18Z TAFS)
Issued at 1151 AM CDT Fri Aug 15 2025

VFR conditions will persist through much of the forecast period
across the Mid-South. Some afternoon TSRA/SHRA could approach TUP,
but have only included mention of VCTS with confidence being low.
Overnight to near sunrise, periods of patchy fog could drop VIS
mainly at MKL and TUP. Light, southerly winds will become variable
tomorrow.

&&

.FIRE WEATHER...
Issued at 1151 AM CDT Fri Aug 15 2025

No fire weather concerns this weekend; MinRH values will remain at
or above 50% with light winds. Conditions do dry out a bit
starting Sunday through Wednesday in addition to very hot
temperatures. Winds should remain light enough to negate fire
weather concerns but the pattern is shifting to hot and dry.

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...Heat Advisory until 7 PM CDT this evening for ARZ009-018-026>028-
     035-036-048-049-058.

     Heat Advisory from 11 AM to 7 PM CDT Saturday for ARZ009-018-
     026>028-035-036-048-049-058.

MO...Heat Advisory until 7 PM CDT this evening for MOZ113-115.

     Heat Advisory from 11 AM to 7 PM CDT Saturday for MOZ113-115.

MS...Heat Advisory until 7 PM CDT this evening for MSZ001-007-008-
     010>012-020-021.

     Heat Advisory from 11 AM to 7 PM CDT Saturday for MSZ001-007-008-
     010>012-020>024.

TN...Heat Advisory until 7 PM CDT this evening for TNZ001-002-019-048-
     049-088.

     Heat Advisory from 11 AM to 7 PM CDT Saturday for TNZ001>003-019-
     020-048>051-088-089.

&&

PUBLIC FORECAST...CAD
AVIATION...CMA