Area Forecast Discussion
Issued by NWS Jackson, MS

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899
FXUS64 KJAN 271522
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
1022 AM CDT SAT AUG 27 2016

.UPDATE...

The forecast is generally on track with much drier air noted in the
12z JAN/BMX soundings (precipitable water < 1.4 inches), but LIX
sounding came in with a very moist 2.2 inch precipitable water, so
there is a strong gradient near the southern portions of the forecast
area. Per latest near term guidance, will maintain afternoon/early
evening shower/thunderstorm chances generally along the Hwy 98
corridor. Farther north, at least over central and eastern MS,
surface dewpoint temperatures should manage to mix down into the
upper 60s this afternoon. Overall, just made minor adjustments to
forecast elements through the afternoon and evening. /EC/

&&

.AVIATION...VFR conditions will prevail for the majority of the period. Patchy
MVFR conditions in fog will develop after 28/06Z and linger until
28/14Z./26/

&&

.PREV DISCUSSION... /issued 445 AM CDT SAT AUG 27 2016/

SHORT TERM...Today through Sunday Night...Our weather through the
short term period will be dominated by the strengthening and
sprawling subtropical ridge to our north. The latitudinally-oriented
axis of this ridge will be close to the Mason-Dixon Line and our
region`s southern location with respect to this axis should keep the
truly oppressive heat at bay and lock in easterly low level flow for
several days to come. The influx of dry air (from the east) related
to this growing ridge helped confine afternoon thunderstorms to
central and western zones yesterday. This dry air should be a more
significant hindrance to afternoon convection in most areas today
although the afternoon inland-cascading seabreeze should get
scattered thunderstorms into far southern zones before the typical
evening stabilization commences. Further inland, many locations in
central and western zones have been quite wet over the past several
weeks and the enhanced evapotranspiration may still yield a stray
storm or two, regardless of mounting negatives on the synoptic
scale. Temperatures in most areas should be a touch warmer than
yesterday owing to more sunshine and less convection, but
fortunately overall lower afternoon humidities will keep heat index
values from exceeding the century mark in most spots.

Tonight should feature mostly dry weather with lows dipping down
into the lower 70s in some spots. As is the case this morning, it
will be hard to rule out a patch or two of fog at daybreak. The
overall setup tomorrow should remain much the same although slightly
more southeast low level flow in the southern half of zones should
start increasing deep moisture levels a bit. This subtle evolution
should allow for afternoon triggering of isolated to scattered
showers and thunderstorms a little further north in the forecast
area than today, but the northern half of zones will still likely
remain dry. Most of the convection Sunday should die down in the
evening, as is typical. However, the far northern fringe of a far
wetter regime setting up along the coast may still allow for a few
showers in our far south through the overnight period Sunday night.

No widespread hazardous weather is expected through the short term
but it is not impossible a stray storm through the weekend could get
a little gusty owing to the downdraft-enhancing effects of
the reservoir of dry air aloft. /BB/

LONG TERM...Monday through Friday...The main theme for much of next
week will be warm and comparatively drier conditions across the
ArkLaMiss. We also continue to monitor the tropics for any potential
development in the Gulf of Mexico.

Early next week, a broad ridge will extend from the Central Plains
across the Mid-South and Ohio Valley to the Mid-Atlantic. By this
time, comparatively lesser deep layer moisture will exist across
most of the CWA, with the exception of the S/W fringes of the area.
Though some diurnal convection will still be around, it will likely
be much more limited compared to the past couple weeks. This should
allow high temps to remain above normal through this time frame,
with heat indices likely peaking around 100 most days.

Heading into the latter half of the week, mid/upper troughing will
develop along the East Coast. This will nudge a weak cold front
southward through the Midwest, attempting to move into our region
around Friday or Saturday. However, the upper trough will shift
eastward, so there won`t be much of an upper level "push" to get the
front through our area. Thus, it will likely stall and quickly
weaken. Nevertheless, as deep layer moisture increases over the
area, this should provide slightly better rain chances toward the
end of the week. There`s also still potential for a tropical low/
tropical wave to pass near the area over the second half of the
week, which could also improve rain chances during that time frame.

Speaking of tropical activity, little has changed this morning with
Invest 99L, still located between Cuba and the Bahamas. It remains a
tropical wave with a weak low pressure center. Limited convection
has been firing up overnight closer to the center, but it remains
disorganized as it continues WNW. It may still be another day or two
before conditions become more favorable for development. As has been
mentioned before, as long as the system remains disorganized,
computer guidance will continue to have a poor handle on how the
system will evolve. For now, there remains some potential for
further development as the wave slowly drifts WNWward across the
eastern Gulf, but whether or not we will even receive rain from such
a system is still uncertain. In the interim, keep checking back for
the latest. /DL/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       94  73  94  75 /   6   7  14  12
Meridian      95  73  96  75 /   6   6  10   8
Vicksburg     94  74  94  74 /   6  10  20  14
Hattiesburg   93  74  93  74 /  13  10  28  20
Natchez       91  73  91  73 /  13  12  34  19
Greenville    93  74  94  74 /   7   6  11   7
Greenwood     93  72  95  74 /   7   6  11   6

&&

.JAN Watches/Warnings/Advisories...
MS...None.
LA...None.
AR...None.

&&

$$



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