599
FXUS64 KMEG 272050
AFDMEG

Area Forecast Discussion
National Weather Service Memphis TN
350 PM CDT Thu Jun 27 2024

...New SYNOPSIS, DISCUSSION...

.SYNOPSIS...
Issued at 345 PM CDT Thu Jun 27 2024

Heat and humidity will begin to increase across portions of
northwest Mississippi on Friday and across much of the Mid-South
on Saturday as heat index values rise to between 100 to 105
degrees, potentially higher in some locations. A cold front will
bring the best potential for showers and thunderstorms to the
Mid-South late Saturday night into Sunday. Very hot temperatures
are expected to return towards latter half of next week along with
afternoon and early evening showers and thunderstorms.

&&

.DISCUSSION...
(This evening through next Wednesday)
Issued at 345 PM CDT Thu Jun 27 2024

GOES-16 Water Vapor satellite trends this afternoon show a
longwave trough axis from New England back through portions of the
Southeast U.S. A quasi-stationary boundary is nearly parallel to
mid-level flow with a surface low located over central Alabama
this afternoon. Light northeasterly flow is present across the
Mid-South this afternoon with dewpoints ranging from the middle
60s to lower 70s on the north side of the surface boundary.
Temperatures as of 3 PM CDT are in the 80s at most locations.

Isolated to scattered rain showers and possibly a thunderstorm are
expected to diminish in coverage tonight with the loss of daytime
heating. Lows tonight will range from the upper 60s to lower 70s.
Temperatures dewpoints will begin to increase on Friday as the
aforementioned surface boundary begins to return north as a warm
front. Afternoon temperatures are expected to warm into the lower
90s at many locations with heat index values potentially ranging
from 100-105 degrees. NBM dewpoints appear to be running a bit
higher than operational model guidance with about a 3-5 degree
spread from the mean to 90th percentile. Dewpoints were trended
slightly lower. There is a potential for a small Heat Advisory
across portions of northwest Mississippi Friday afternoon.
However, uncertainty with the rapid increase dewpoints and the
typical high dewpoint biases with the CKM and UTA observations
lean towards lower confidence in headlines at this moment. Confidence
is higher with the potential for heat headlines on Saturday with
a few locations that might see heat warning criteria if these
higher dewpoints are actually realized. This will be re-evaluated
with the 00Z model data that will arrive later tonight.

Short-term model trends indicate another weak cold front embedded
within weak northwest flow aloft will drop into the Lower
Mississippi Valley late Saturday night into Sunday. As with
yesterday`s system, the better forcing will remain displaced
northeast over the Ohio Valley with overall shear remaining weak
at best around 20 kts and mid-level lapse rates remaining
relatively weak. Thus, strong to severe thunderstorm potential
remains on the low end at this time.

Long-range operational and ensemble model trends indicate building
heights across the region next week. This will result in
temperatures returning to the middle to upper 90s especially
towards the 4th of July and the potential for diurnally driven
showers and thunderstorms for mid to late next week.

&&

.AVIATION...
(18Z TAFS)
Issued at 1230 PM CDT Thu Jun 27 2024

While VFR conditions are expected to prevail at all sites through
the TAF period, MVFR CIGS may persist for a little while longer
at MEM and TUP this afternoon. Patchy fog looks to reduce
visibilities at TUP overnight. Gusty northeast winds will
eventually slacken later this evening.

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&

$$

PUBLIC FORECAST...CJC
AVIATION...JPR