Flash Flood Warning 86, NWS Jackson, MS

Area Forecast Discussion
National Weather Service Jackson MS
335 AM CDT Thu Aug 13 2020

.DISCUSSION...
Today and Tonight: Persistent mostly warm top convection continues
to fester this morning over the ArkLaMiss Delta region as 0-3km
theta-e advection occurs in the deep tropical airmass (PWs ~ 2.5").
While cells have been and will continue to be slow moving given the
10-15 knot 0-3km bulk shear vectors, the absence of any low level
feature to focus on will keep amounts only locally heavy as has been
the case so far. Recent convective rainfall amounts have done little
to create an environment for flooding as seen in the 1hr FFG values
near 3.5" over much of the area. As such, will not continue the
limited flooding threat in the HWO for today.

Despite the difficulties in the CAM data resolving this early
morning convection, their diurnal convective solutions for later
today still seem reasonable with enhanced coverage over central
sections given the location of the slow moving mid level shortwave,
best ascent and moisture./GG/

Friday through Sunday: A hot/humid pattern with ongoing potential
for showers and storms will continue through this weekend. The
region remains on the eastern periphery of a ridge centered over the
Four Corners and extending across the Southern Plains. An unhurried
shortwave and associated weak surface low will serve as a trigger
for convective development as they move eastward across the Mid
South. Similar to what was being advertised for this morning, CAM
guidance is once again hinting at ongoing convection moving into the
ArkLaMiss Delta on Friday morning. Through the day, the low level
convergence axis (and better rain chances) will shift eastward
extending from South MS into AL. By Saturday and Sunday, these
features will shift east of the area; however, considerable deep
layer moisture will remain and additional weak disturbances will
promote continued isolated to scattered convection. Nevertheless,
decreasing precip coverage should result in increasing daytime
temperatures. With moderately steep mid level lapse rates and
marginally strong deep layer shear forecast, a few stronger storms
will be possible each day as we have seen in recent days. Rainfall
could also be locally heavy given the moist environment and some
potential for training convection along these low level convergence
axes.

Dewpoints will remain rather high through this time frame, running
in the mid to upper 70s in most areas during the day. Outside of
convective activity with temps rising into the lower to middle 90s,
this will result in heat indices near 105F at times. The highest
confidence of this occurring is roughly west of I-55 where rain
chances are somewhat lower. Again, with the potential for early day
convection on Friday, there is some uncertainty with regards to
reaching these thresholds but there is still conditional potential
for heat indices around 105F in the western areas. Given this, the
currently advertised limited heat stress in the HWO/graphics will be
maintained.

Monday through Wednesday: A break from the current pattern is in the
cards for next work week as a summertime cold front moves across the
area. Though surface winds will begin to shift as early as Sunday,
the actual theta gradient/change in airmass won't reach the area
until the day on Monday. PW, which has been running in the 1.5 to 2
inch range, will fall to around or even below 1 inch in most areas
by midweek. POPs will trend downward from north to south and through
time as drier air begins to work into the area. More pleasant and
slightly cooler conditions are expected Tuesday and Wednesday in the
wake of the front. /DL/

&&

.AVIATION...
06Z TAF discussion: Scattered to numerous showers and thunderstorms
will continue overnight between GLH and GWO as MVFR conditions
develop. While VFR conditions will become prevalent by mid morning,
scattered to numerous showers and thunderstorms will develop over
the region and continue thgrough late afternoon. Periodic IFR/MVFR
conditions can be expected where storms occur./GG/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       90  72  89  73 /  68  35  69  22
Meridian      90  72  90  73 /  65  48  73  30
Vicksburg     91  74  91  75 /  59  30  54  20
Hattiesburg   90  73  90  73 /  64  34  74  26
Natchez       91  74  90  74 /  58  20  54  16
Greenville    89  73  89  72 /  50  31  44  19
Greenwood     88  72  89  71 /  68  35  45  22

&&

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

&&

Hazardous Weather Outlook
National Weather Service Jackson MS
344 AM CDT Thu Aug 13 2020

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
140845-
Ashley-Chicot-Morehouse-West Carroll-East Carroll-Richland-
Madison LA-Franklin LA-Catahoula-Tensas-Concordia-Bolivar-
Sunflower-Leflore-Grenada-Carroll-Montgomery-Webster-Clay-Lowndes-
Choctaw-Oktibbeha-Washington-Humphreys-Holmes-Attala-Winston-
Noxubee-Issaquena-Sharkey-Yazoo-Madison MS-Leake-Neshoba-Kemper-
Warren-Hinds-Rankin-Scott-Newton-Lauderdale-Claiborne-Copiah-
Simpson-Smith-Jasper-Clarke-Jefferson-Adams-Franklin MS-Lincoln-
Lawrence-Jefferson Davis-Covington-Jones-Marion-Lamar-Forrest-
344 AM CDT Thu Aug 13 2020

This hazardous weather outlook is for portions of southeast
Arkansas, northeast Louisiana, and central and south Mississippi.

.DAY ONE...Today and Tonight

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

Heat indices near 105 degrees during the late morning and
afternoon hours Friday through Sunday will result in increasing
heat stress, mainly for areas west of Interstate 55.

(https://www.weather.gov/images/jan/graphicast/1.png)

.SPOTTER CALL TO ACTION STATEMENT...
The activation of storm spotters, HAM radio operators, and
emergency management personnel in support of severe weather
operations is not expected through next Wednesday.

DL

&&

...HAZARD LEGEND...

No short term hazards expected.

...USEFUL WEATHER WEB PAGES (URLS)...

NWS JAN Home page...
   https://www.weather.gov/jan
Stay Aware, Stay Safe NWS JAN Briefing Page...
   https://www.weather.gov/jan/safe
Latest Weather Briefing...
   https://www.weather.gov/jan/weather_briefing

Tropical page...
   https://www.weather.gov/srh/tropical?office=jan
National Hurricane Center Home Page...
   https://www.nhc.noaa.gov/
Find NWS JAN on Facebook...
   https://www.facebook.com/NWSJacksonMS
Follow NWS JAN on Twitter...
   @NWSJacksonMS
Follow NWS JAN on Youtube...
   https://www.youtube.com/user/NWSJacksonMiss

Special Weather Statement
National Weather Service Jackson MS
436 AM CDT Thu Aug 13 2020

MSZ042-043-048-049-131000-
Hinds MS-Yazoo MS-Rankin MS-Madison MS-
436 AM CDT Thu Aug 13 2020

...A STRONG THUNDERSTORM WILL AFFECT SOUTHWESTERN RANKIN...
SOUTHEASTERN YAZOO...HINDS AND SOUTHWESTERN MADISON COUNTIES UNTIL
500 AM CDT...

At 435 AM CDT, Meteorologists were tracking a strong thunderstorm
near Brownsville, or 9 miles north of Clinton. This storm was nearly
stationary.

This strong thunderstorm will be near...
   Flora and Pocahontas around 500 AM CDT.

Other locations impacted by this storm include Learned.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3249 9059 3250 9058 3250 9057 3251 9055
      3253 9055 3253 9059 3254 9059 3255 9060
      3258 9060 3271 9009 3215 8999 3214 9057
TIME...MOT...LOC 0935Z 280DEG 3KT 3247 9039

GRG