Special Weather Statement, NWS Jackson, MS

Area Forecast Discussion
National Weather Service Jackson MS
1253 PM CDT Sat Jul 1 2017

.UPDATE...
Updated for 18Z aviation discussion

&&

.AVIATION...
18Z TAF discussion:
Stratus was slowly burning off this morning, so MVFR conditions
were lingering at a few locations going into the afternoon.Looking
for scattered to numerous showers and thunderstorms again this
afternoon, with most of the activity diminishing in the early
evening. Models continue to show a disturbance passing to the
northwest of the cwa with convection blowing up the nw portions of
the area and spreading east along the highway 82 corridor. Again,
the higher resolution models may be over doing it, but decided to
add showers and thunderstorms around 6z for GLH, 8z for GWO and
after 12z for GTR Sunday morning. Looks like there could be more
stratus tonight, so showed lower ceilings starting around 10z
elsewhere. Low clouds could move in a littler earlier.

&&

.DISCUSSION...
Today and Tonight: Remnant cold pool boundary from overnight MCS in
AR moving into the Delta region at the moment will most likely aid
in convective development later today where it eventually sets up.
Meanwhile, troughiness over the MS valley today will bring the
westerlies more firmly into the forecast area and allow a potent
shortwave to approach from the ArkLaTex this afternoon. Localized
forcing along the boundary and better lapse rates with the cooling
aloft should yield some robust convection during the afternoon as
temperatures climb into the lower 90s. These conditions have allowed
our local microburst parameter to respond with good potential over
the north where best lapse rates will exist. With the loss of
heating, convection will slowly wind down during the evening. /26/

Sunday through next Saturday morning: Hot and humid conditions
with diurnal storm chances will remain through the July 4th
holiday and through the week. By Sunday, that trough and surface
low over the northern Great Lakes will have ejected into eastern
Canada. The cold front will be draped across the Appalachians into
the mid-Mississippi Valley with strong surface ridging extending
through that area. In addition, surface and mid- level ridging
will be situated over the Gulf of Mexico with nearly 590-595DM
500mb mid-level ridging. Models show some of this surface ridging
and slightly drier air advecting in from the south towards Lake
Charles and into the southwest towards Natchez and the
southwestern periphery of northeast Louisiana. This should limit
convection chances there while elsewhere nearly an inch and three
quarters to nearly 2 inch PWs will reside. With plenty of
moisture, bumped up PoPs into likely from a line near Fountain
Hill, Arkansas towards Quitman, MS and north. There could be some
stronger to possibly severe wet microbursts as there is upper 20s
vertical totals, good mid level lapse rates nearly 6.5-7 deg C and
some weak flow. There isn't as defined of a shortwave and
trough/front as is the case today but there could be some
potential. Will monitor the trends and may have to introduce
something in later forecasts for possible isolated severe storm
potential. In addition, slow moving storms and high levels of
moisture could bring isolated torrential downpours.

As the ridge builds to our west-southwest by the start of the week,
low-mid level height (700mb and 850mb) and temperature anomalies
will increase. This will lead to some drying in areas to the western
zones while areas to the east convection chances will linger through
mid-week. Expect diurnal thunderstorm chances with lingering
microburst potential through the week, especially over eastern
areas. Bigger impactful weather looks to be the heat as temperatures
will be in the low-mid 90s with dewpoints in the mid 70s. This will
lead to increasing oppressive conditions, mainly Monday to mid-week,
possibly into the holiday (July 4th). Very confident this will be a
concern along and west of the I-55 corridor with a little less
confidence in the east due to increasing coverage of convection. Any
areas on the periphery of any storm could be quite oppressive. Added
this to the HWO/graphics to account for this increasing heat stress.

Expect hot and humid conditions to continue with slightly cooler
temperatures as a shortwave trough ejects through the mid-
Mississippi Valley. This in addition to an extremely anomalously
strong ridge over the Rockies will amplify the upper trough and
bring NW flow and a cold front, possibly backdoor front, down
towards the area by late week into early next weekend. Thankfully
this will help temper down our oppressive heat stress concerns. /DC/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       90  74  91  74 /  42  36  49  10
Meridian      90  73  90  73 /  38  33  56  18
Vicksburg     90  74  92  74 /  42  33  35   7
Hattiesburg   89  75  92  73 /  37  27  35  16
Natchez       89  73  92  73 /  29  26  16   5
Greenville    90  75  91  74 /  38  40  56  12
Greenwood     88  73  90  74 /  38  40  56  17

&&

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

&&

Hazardous Weather Outlook
National Weather Service Jackson MS
226 PM CDT Sat Jul 1 2017

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-021930-
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-
226 PM CDT Sat Jul 1 2017

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 Sunday

SEVERE THUNDERSTORMS
THREAT...Marginal
TIMING...The rest of this afternoon through tonight

Strong to severe storms will be possible through tonight. Damaging
wind gusts to 60 mph and quarter sized hail will be the primary
risks. Torrential rains may lead to localized flooding.

(www.weather.gov/images/jan/graphicast/image1.png)

.DAYS TWO THROUGH SEVEN...Sunday night through Friday

Humid conditions and increasing temperatures may cause heat index
values to peak near 105 degrees each afternoon through mid week.

(www.weather.gov/images/jan/graphicast/image2.png)

.SPOTTER CALL TO ACTION STATEMENT...
The activation of storm spotters, HAM radio operators, and
emergency management personnel in support of severe weather
operations may be needed for portions of the region remainder
of the afternoon through tonight.

MSZ072>074-021930-
Marion-Lamar-Forrest-
226 PM CDT Sat Jul 1 2017

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

.DAY ONE...Tonight and Sunday

SEVERE THUNDERSTORMS
THREAT...Marginal
TIMING...Through the remainder of this afternoon and evening

Strong to severe storms will be possible through this evening.
Damaging wind gusts to 60 mph and quarter sized hail will be the
primary risks. Torrential rains may lead to localized flooding.

(www.weather.gov/images/jan/graphicast/image1.png)

.DAYS TWO THROUGH SEVEN...Sunday night through Friday

Humid conditions and increasing temperatures may cause heat index
values to peak near 105 degrees each afternoon through mid week.

(www.weather.gov/images/jan/graphicast/image2.png)

.SPOTTER CALL TO ACTION STATEMENT...
The activation of storm spotters, HAM radio operators, and
emergency management personnel in support of severe weather
operations may be needed for portions of the region remainder
of the afternoon.

21

&&

...HAZARD LEGEND...

*SEVERE THUNDERSTORMS*
High...Significant severe thunderstorms are expected.
Moderate...Severe storms expected with significant
 severe weather possible.
Enhanced...Severe storms expected.
Slight...Severe storms possible.
Marginal...Isolated severe storms possible.

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

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

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

...ADDITIONAL URLS FOR SEVERE WEATHER ISSUES...

Storm Prediction Center (SPC)...
   www.spc.noaa.gov/
Meso Analysis...
   www.spc.noaa.gov/exper/mesoanalysis/
Day 1 through 3 Outlooks...
   www.spc.noaa.gov/products/outlook/
Storm Reports...
   www.spc.noaa.gov/climo/online/

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>