Area Forecast Discussion
Issued by NWS Jackson, MS

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FXUS64 KJAN 280200 AAA
AFDJAN

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
900 PM CDT WED JUL 27 2016

.UPDATE...
Most of the convection has dissipated by now with the exception of
rain still falling along the MS river in Bolivar County. Slight
redevelopment is expected again after 06Z tonight with even more
redevelopment expected near 12Z. Most locations are already in the
mid/upper 70s this evening due to today`s rainfall. These temps will
remain mostly steady through the night. But as cloud cover thins a
bit in the wee morning hours, temps may fall into the lower 70s,
especially in southern locations furthest from the mid-level low.
Adjusted the pops and wx grids for the rest of the night. /10/

&&

.AVIATION...
Much of the precip has dissipated with what`s left over
the NW as of 02z. Look for the focus to quickly shift to MVFR
ceilings for several of the sites between 03-06z then a transition
to IFR at those same locations between 06-08z. Precip activity will
likely get going again later and closer to sunrise and then expand
through morning and the afternoon. Look for the restricted ceilings
to linger with improving to a mix of MVFR/VFR by 17-19z. /CME/

&&

.PREV DISCUSSION... /issued 416 PM CDT WED JUL 27 2016/

SHORT TERM...

Tonight through Saturday morning...

Mid-level circulation, even evident in satellite imagery over
southeast Arkansas, in conjunction with a tropical airmass is
leading to widespread convection, with heavy rainfall occurring in
many locations today. Widespread showers and storms are ongoing this
afternoon with another complex of heavy rain and storms moving into
the southern portions of northeast Louisiana and southwest
Mississippi. Due to 20-30kt southerly low-level flow, anomalous
moisture (2+ inch PW`s) has been advected into the region. This in
addition to efficient isentropic lift and moisture
convergence/transport will help maintain heavy rain into the
overnight and spread northeast. Moisture transport will lift north-
northeast through central-northeast Mississippi into Alabama tonight.
Corfidi vectors will still be light to near opposite of northeast
storm movement, which will help backbuilding. Any areas that
received heavier rainfall could have some issues with flooding as
some radar totals reaching 2+ inches in some areas, especially in
southwest Mississippi. One important note of today is the widespread
rain and clouds have finally broken the 90 degree streak at many
locations across the region, which has extended around the last month
(~30 to 40 days).

The mid-level low will slowly lift northeast this evening along a
stalled boundary in central Arkansas to southern Missouri as the
region is situated in the weakness between the upper ridge over the
Atlantic coastline and another over the desert southwest/western
Rockies. This pattern will help the upper low to gradually lift to
the north-northeast tonight. The low level jet will help keep
efficient moisture transport, in addition to PW`s near 99th
percentile in north-central Mississippi, hanging up along the Highway
82 corridor. Thus, decided to leave the HWO the same as earlier but
extending into tomorrow morning. Due to slow shower/storm movement
and some backbuilding potential along the same corridor in north-
Mississippi, flash flooding will continue to be possible. Expect the
best moisture/lift to move out by tomorrow afternoon. However, near 2
inch PW`s will remain around and shower/storm development will be
widespread again. This will keep highs cooler near the mid 80s in the
Highway 82 corridor to low 90s elsewhere.

The region will remain in an unsettled pattern into the weekend.
Upper heights may build in slightly from the southeast, helping to
increase highs into the lower 90s on Friday. GFS/NAM show a ~1010mb
surface low moving through the mid-Mississippi Valley while the Euro
is weaker and less amplified. Regardless, increasing lift from this
shortwave aloft and surface feature/stalled front near the region will
help spark shower and storm chances along the boundary. With this
and moisture abundant near 2 inches around, scattered showers/storms
will linger into the weekend. /DC/

LONG TERM...

Saturday through Tuesday...

Above normal rain chances will continue through early next week, but
a return to above normal temperatures may be in the offing.

By this weekend, the subtle upper trough axis will remain over the
eastern U.S. and a corridor of plenteous moisture (with PW forecast
to be as high as around 2 - 2 1/4 in) will still exist over the Lower
MS Valley. These features will linger into the weekend, bringing a
continuation of higher rain chances. PoPs will be sustained in the
higher-end chance to likely categories each day. Certainly some folks
will receive heat relief courtesy of the increased precip coverage,
but outside of the rain, high temps will remain near normal.

Minor changes are afoot heading into next week. The weak upper
trough will be superseded by a building mid/upper level ridge over
the nation`s mid-section. This ridge is expected to remain "dirty"
and atmospheric moisture will continue to be plentiful, so rain
chances will remain above normal through the end of the forecast
period. However, daytime highs will likely begin to tick back up a
degree or two, and heat stress could once again become more of a
concern. /DL/DC/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       74  91  74  92 /  17  57  29  37
Meridian      74  90  74  95 /   9  40  22  33
Vicksburg     75  88  74  92 /  27  63  24  41
Hattiesburg   74  93  74  92 /  10  27  22  33
Natchez       73  87  73  90 /   9  50  23  32
Greenville    74  84  73  90 /  42  72  33  40
Greenwood     74  84  72  89 /  39  75  39  39

&&

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

$$


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