160
FXUS64 KMEG 140436
AFDMEG

Area Forecast Discussion
National Weather Service Memphis TN
1136 PM CDT Sat Jul 13 2024

...New AVIATION...

.SYNOPSIS...
Issued at 243 PM CDT Sat Jul 13 2024

A strong upper level ridge over the southern Rockies will expand
eastward into the lower Mississippi River Valley through Tuesday.
This will result in a gradual warming trend for the Midsouth,
with Tuesday likely the hottest day. Afternoon heat indices of 100
to 105 will prevail Sunday and Monday, warming to 105 to 110 on
Tuesday.

Relief from the heat will arrive late Wednesday, as as a cold
front brings scattered thunderstorms. Moderate temperatures and
humidity levels are expected Thursday through Saturday.

&&

.DISCUSSION...
(This evening through next Friday)
Issued at 243 PM CDT Sat Jul 13 2024

Primary forecast concern remains the heat through middle of next
week.

Midday water vapor imagery showed a weak subtropical jet extending
from east Texas into the Ohio River Valley, in advance of a
positively-tilted upper level trough. This trough will weaken and
lift east of the Midsouth through Tuesday. Concurrently, a 597dam
500mb ridge centered over the 4-corners region will expand
eastward to the lower Mississippi River Valley. Under this
pattern, 850mb temps over the Midsouth will warm around 1C per
day from Sunday onward, peaking at reaching 21C on Tuesday and
Wednesday.

While heat indices will likely touch 105 in a few locations on
Sunday, confidence is too limited with respect to areal and
temporal extent for a Heat Advisory issuance at this time. Heat
headlines will be more probable on Monday and likely on Tuesday,
with Tuesday afternoon heat indices of 105 to 110 over much of the
area.

Relief will arrive late on Wednesday, courtesy of a longwave
upper level trough dropping into the Great Lakes and Midwest from
Quebec. Height falls from this system will be sufficient to drive
a surface cold front through the Midsouth Wednesday night and
Thursday. While Wedensday`s temperatures will likely be tempered
by thunderstorms and associated cloudiness, prefrontal dewpoint
cooling will likely drive peak heat indices above 100, perhaps
above 105, along and south of the I-40 corridor. By Thursday
afternoon, heat indices likely won`t warm out of the 80s north of
I-40, and lower 90s to the south.

Temperatures and dewpoints will slowly warm to near climatology by
next weekend, under a weak longwave trough. Medium range models
depict sufficient deep layer shear to support mainly daytime
scattered thunderstorms.

PWB

&&

.AVIATION...
(06Z TAFS)
Issued at 1136 PM CDT Sat Jul 13 2024

VFR conditions will prevail. Showers and thunderstorms will near
TUP tomorrow afternoon as a mid-level low pulls away from the
region. Winds will prevail southerly by the end of the period.

DNM

&&

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

$$

PUBLIC FORECAST...PWB
AVIATION...DNM