Severe Thunderstorm Warning 373, NWS Jackson, MS

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
651 PM CDT Sat Sep 23 2017

.UPDATE...
Updated for 00Z aviation discussion

&&

.AVIATION...
00Z TAF discussion:
Isold SHRA/TSRA wl cont over cntrl and se MS through 02Z before
dissipating. Otherwise, VFR conds wl prevail areawide tonight. The
exception wl be over se MS where IFR vsbys wl be psbl 10Z-14Z
Sun. After 14Z VFR conds are expected to prevail areawide until
after 19Z when isold-sct TSRA activity is expected. Greatest
coverage of TSRA is expected south of I-20 into Sunday evng. /22/

&&

.DISCUSSION...

Through Sunday Afternoon: The combination of slightly above
average heat and humidity over the region and an upper low
translating west over the Gulf States is starting to kick off
isolated showers and storms over the forecast area in the past few
hours. Expect a general increase in coverage through 5 pm before
activity slowly diminishes through early to mid evening. A few
storms could produce brief gusty winds but the potential for a
truly severe storm is too low to include in the HWO or graphics.
Tonight radiational cooling conditions will be decent by late
evening after most of the clouds disperse and thus expect a
general repeat of early this morning, with lows mainly in the
upper 60s and a bit of patchy fog by daybreak.

For Sunday, the upper level low currently moving toward the Lower
MS Valley will be sitting right atop the region and continuing to
ensure at least isolated showers and thunderstorms form during the
afternoon hours. Previous model consensus suggested there could
be numerous showers and storms late in the day, at least over
southeastern zones. However, latest consensus is less impressed
with moisture quality and depth over even southern portions of MS
and thus with this package we will refrain from going overly-
aggressive with pops. Temperatures will remain warm but will
likely be a degree (maybe two) cooler in most areas than was the
case this afternoon. /BB/

Sunday night through next week...

By Sunday night a weak mid/upper low will become centered over the
ArkLaMiss between an deep trough over the western CONUS and steep
ridging over the eastern portions of the country. This weakening
feature will begin to phase with the deep trough on Monday. However
the flow associated with this low will pull enough moisture into the
southern portions of the region on Monday to result in chances of
showers/storms mainly in the afternoon south of the I-55 corridor.
More isolated activity is possible throughout the rest of the region
on Monday. Temperatures on Monday will remain well above average.
Temperatures will even increase 1-2 degrees areawide on Tuesday and
Wednesday as upper level heights increase over the region. There
will only enough moisture on Tuesday and Wednesday to support
isolated diurnal activity. The closed low over the west will begin
to push towards the Upper Plains and into Central Canada by midweek
dragging a front though the ArkLaMiss on Thursday. Models are pretty
conservative with any precip along the front. Another closed low
diving south towards the Great Lakes from Canada will help push a
stronger, secondary, also dry, front through the region late in the
week or early in the weekend. More Fall-like weather and
temperatures will exist behind the front./JPM3/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       68  90  68  88 /   9  24  21  25
Meridian      67  89  68  87 /  13  25  22  23
Vicksburg     69  90  68  89 /   8  20  17  17
Hattiesburg   67  88  67  86 /  21  41  37  42
Natchez       69  89  67  87 /  10  28  24  31
Greenville    69  91  67  89 /   8  15  13  16
Greenwood     69  91  68  88 /   8  18  15  17

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.

&&

JPM3/22/BB