Area Forecast Discussion
Issued by NWS Memphis, TN

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FXUS64 KMEG 190418

Area Forecast Discussion
National Weather Service Memphis TN
1118 PM CDT Sun Aug 18 2019

.UPDATE...Aviation Discussion.


.PREV DISCUSSION... /issued 903 PM CDT Sun Aug 18 2019/

DISCUSSION...GOES-16 Satellite trends/00Z upper air analysis
depicts a weak mid-level shortwave trough located across Illinois
then into West Tennessee and North Mississippi. This mid-level
shortwave acting as a lifting mechanism combined with instability
triggered the isolated to scattered showers and thunderstorms
across the Mid-South this afternoon into this evening. KNQA WSR-
88D radar trends have shown some dissipation of showers and
thunderstorms across the forecast area with the only areas
remaining thus far along a line from Jonesboro, Arkansas to
Ripley, Tennessee and including a small area near West Memphis. As
of 8 PM CDT, temperatures across the Mid-South are predominantly
in the 70s to lower 80s.

Latest short term model trends including Convective Allowing
Model (CAM) solutions and especially the HRRR suggest this
activity should continue to weaken for the rest of the night and
perhaps ending by 6Z if not sooner. Some adjustments to rain
chances, temperatures, and the potential for some patchy fog
overnight will be made to the forecast to account for these short
term trends.

Updated grids will be available shortly.


PREV DISCUSSION... /issued 620 PM CDT Sun Aug 18 2019/

UPDATE...Aviation Discussion.

PREV DISCUSSION... /issued 238 PM CDT Sun Aug 18 2019/

Higher humidity across a good portion of the area this
afternoon...with a few locations in the current heat advisory
reaching 105F+ this hour. Winds were also higher with most
observations in the 10-15 mph range. Showers had developed across
the southwest Delta counties...with thunderstorms just outside of
the CWA.

Late this afternoon and tonight...have increased PoPs across the
northern and western counties for tonight...and late this
afternoon based off the current radar. CAM`s are indicating more
activity this evening along this morning`s lingering outflow
boundary draped across southeastern Missouri/northern Arkansas. A
convective watch was issued just north of the AR/MO border a short
while ago. Main threat would be strong gusty winds that could push
south across the western counties this evening. Plan on adding a
strong storm wording in the HWO. Current heat advisory goes
through 8pm.

Monday and changes really necessary this period.
Temperatures will climb into the low and mid 90s with potentially
a larger area of 105F+ heat indices. Have held off on extending
or issuing a new heat advisory for Monday as tonight`s convection
could disrupt both timing and area needed. Isolated convection
can be expected both days with activity quickly waning during the
overnight hours. Will have to watch for any lingering outflow
boundaries that enhance storm intensity.

Wednesday through Friday...models still suggesting the wettest
period of the course of next week...mainly as the eastern edge of
the Southern Plains ridge breaks down as heights gradual lower
over the Midwest. A weak surface front will edge closer to the
KY/TN and MO/AR borders sometime early Thursday with a series of
passing shortwaves aloft aiding in convection coverage and
intensity. Some of these storms may be strong as well...but will
leave that wording out of this afternoon`s HWO. Highs will range
from the upper 80s to low 90s...with Wednesday posing the best day
for a heat advisory across southwest portions of the area.

Next weekend...extended models show seasonal to slightly above
normal temperatures with isolated diurnal convection.




VFR conditions should prevail through the next 24+ hours at all
sites. Light winds, generally from the South. Scattered showers
and thunderstorms are expected to develop again tomorrow. Neither
coverage nor intensity look significant at this time.




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