Special Weather Statement, NWS Jackson, MS

Area Forecast Discussion
National Weather Service Jackson MS
624 PM CDT Wed Aug 18 2021

.UPDATE...
Updated for 00Z aviation discussion

&&

.AVIATION...
00Z TAF discussion:
A bit more coverage of afternoon convection is occurring across
the region and some storms have affected a few TAF sites(mainly
along the Highway 82 corridor). Any storms that occur will have
the capacity to briefly lower conditions to MVFR or IFR status
with a reduction in vis mostly. VFR conditions should return as
storms diminish or move out of the region this evening. Some MVFR
stratus might occur before daybreak tomorrow with VFR conditions
expected to continue tomorrow outside of any storms that develop,
mainly during the afternoon hours. /28/

&&

.DISCUSSION...

A low amplitude shortwave trough will lift away from the area
tonight with a general weakness in the upper pattern persisting
into tomorrow before stronger ridging builds in by the weekend.
Showers and thunderstorms this evening may linger into the
overnight, especially along and north of the Hwy 82 corridor
closer to upper forcing from the departing wave. Overnight
temperatures will be mild as a low stratus cloud deck builds in
and precludes efficient cooling with lows in the low to mid 70s.
For tomorrow, a very moist airmass characteristic of 2-2.5" PWATs
combined with a weakness in the upper pattern will help foster
scattered to numerous showers and thunderstorms. Activity will
likely begin to ramp up during the early to mid morning hours with
coverage peaking during the early to mid afternoon. Near moist
adiabatic lapse rates and tall skinny CAPE profiles will generally
limit severe potential, although a few isolated strong storms and
perhaps a marginally severe storm can never be ruled out in a
humid late summer airmass. Isolated flash flooding cannot be ruled
out either given the aforementioned moisture, however, most storms
should stay progressive enough to limit coverage of heavier
rainfall amounts. Increasing cloud cover and an early start to
convection will likely keep temperatures in check with afternoon
highs ranging from the upper 80s to low 90s. Locations that are
slower to see storms may see heat indices peak near 105 degrees,
but given timing of convection will hold off on any heat mention
in the HWO/graphics. /TW/

Thursday night through early next week:

The subtropical ridge will build across the Deep South through
the extended period, bringing hotter conditions and decreasing
rainfall coverage. While the mid level heights will not be
especially anomalous for late August, the combination of increased
west-northwest low level flow, the persistence of the ridge, and
a reduction in convective rainfall coverage, should all lend to an
increasingly hot low level thermal ridge. So it looks like we
could potentially observe dangerous levels of heat stress toward
the end of the long range forecast, especially in the Sun-Tue time
frame when H850 temperatures > 21C are looking more likely in the
global models. /EC/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       75  91  74  90 /  39  76  21  46
Meridian      74  90  73  89 /  32  70  21  55
Vicksburg     76  91  76  92 /  34  78  20  31
Hattiesburg   75  92  75  91 /  21  70  20  42
Natchez       74  90  74  92 /  51  77  20  29
Greenville    74  89  74  89 /  35  77  20  39
Greenwood     74  89  74  89 /  52  79  20  51

&&

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

&&

28

Hazardous Weather Outlook
National Weather Service Jackson MS
158 PM CDT Wed Aug 18 2021

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
191900-
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-
158 PM CDT Wed Aug 18 2021

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

.DAY ONE...Tonight and Thursday

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Thursday night through Tuesday

The probability for widespread hazardous weather is low.

.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 Tuesday.

1

&&

...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
712 PM CDT Wed Aug 18 2021

LAZ007>009-015-190100-
Morehouse LA-Richland LA-East Carroll LA-West Carroll LA-
712 PM CDT Wed Aug 18 2021

...Strong thunderstorms will impact portions of central Morehouse,
north central East Carroll, northern Richland and West Carroll
Parishes through 800 PM CDT...

At 712 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 6 miles south of Bastrop to near Goodwill.
Movement was northeast at 20 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Bastrop, Oak Grove, Goodwill, Galion, Darnell, Mer Rouge, Forest,
Collinston, Pioneer and Oak Ridge.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3288 9191 3295 9121 3250 9157 3249 9193
      3252 9190 3255 9192 3258 9192 3260 9193
      3263 9192 3265 9192 3265 9191 3266 9191
      3267 9193 3266 9194 3268 9196
TIME...MOT...LOC 0012Z 217DEG 17KT 3269 9195 3272 9158

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

19

Special Weather Statement
National Weather Service Jackson MS
722 PM CDT Wed Aug 18 2021

ARZ074-190045-
Ashley AR-
722 PM CDT Wed Aug 18 2021

...A strong thunderstorm will impact portions of northeastern Ashley
County through 745 PM CDT...

At 722 PM CDT, Doppler radar was tracking a strong thunderstorm near
Snyder, or 7 miles northeast of Hamburg, moving northeast at 15 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Snyder.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3339 9174 3339 9146 3318 9164 3324 9179
TIME...MOT...LOC 0022Z 208DEG 14KT 3328 9168

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

19