Severe Thunderstorm Warning 542, NWS Jackson, MS

Area Forecast Discussion
National Weather Service Jackson MS
350 PM CDT Thu Aug 3 2023

...New DISCUSSION...

.DISCUSSION...
Issued at 348 PM CDT Thu Aug 3 2023

Tonight and Friday: Mid afternoon regional radars and satellite
imagery showed a band of storms over our northeast most zones that
extended east into Alabama. This activity will continue to sag
south through the afternoon into early evening before dissipating.
No severe storms are anticipated in our CWA. Otherwise, hot and
humid conditions will be the main focus through Friday as our CWA
remains on the eastern periphery of a stout mid level ridge. This
ridge will begin shifting back to the west tonight and Friday.
This will allow another disturbance topping the ridge this
afternoon to drop over our eastern zones Friday. This disturbance
is expected to help develop storms tonight that may spread into
our northeast most zones prior to noon Friday. This activity is
expected to spread over the eastern half of the CWA during the
afternoon. A few of the storms may become severe and produce
damaging wind gusts. It's possible that the convection may occur
early enough to mitigate the excessive heat concerns for Friday
but for now the Excessive Heat Warning will remain in effect
through the weekend for most of our CWA while east Mississippi
remains in a Heat Advisory. /22/

Friday night through next week:

The main thing to watch for in this portion of the forecast will be
the ridge over the south central/southwestern US over the weekend
and into next week. This 595dam ridge will shift a bit westward this
weekend and allow for higher rain chances to move into our eastern
CWA. Expect the daily afternoon convection on Saturday and Sunday
then. Despite the rain chances, the excessive heat will continue
throughout the weekend. The rain may temporarily alleviate the heat
but the humidity after the rain ends will keep heat indices a
concern. Also, temps will climb quickly each morning and will likely
peak before any convection moves in.  For these reasons, the heat
advisory and excessive heat warnings will persist.

A mid-level low over the Northern Plains will begin evolving into an
open trough as it shifts eastward into the Upper Midwest and then
deepens as it moves east of the ridging and into the Great Lakes
region. The GFS and ECMWF differ in the strength of this trough with
the GFS keeping an open wave while the ECMWF attempts to develop a
closed low. The ECMWF definitely manages to develop a stronger
surface low than the GFS. Either way, they both bring a frontal
boundary into the CWA by Monday afternoon. Heights will fall and a
slight relief from the heat will result. Highs in the mid to upper
90s are expected on Monday and then upper 80s to mid 90s on Tuesday.
At this point, even mid 90s are a welcome sight after a week of
100s! The humidity will be higher at this time though as more
moisture moves into the region. PWs of 2-2.5in. will be possible.
This means that while the temps will be slightly cooler, the high
heat indices will remain. Tuesday looks to be the best chance for
skipping out on the need for a heat advisory. Beyond that though,
the high heat looks to ease back in towards the second half of next
week.

As for precip associated with the front on Monday, scattered storms
throughout the area are expected to develop in the afternoon. The
best chances for widespread rain will come on Tuesday and Wednesday
though as the frontal boundary washes out and mid-level northwest
flow brings some MCS-type systems into our region. Interestingly,
both the deterministic GFS and ECMWF allude to this even though
we're still several days out. Timing and coverage will be refined in
future forecasts. /10/

&&

.AVIATION...
(18Z TAFS)
Issued at 1239 PM CDT Thu Aug 3 2023

VFR conditions and a light sw wind wl prevail through the TAF
period. /22/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       78 101  77 100 /   0  20  10  30
Meridian      76  98  75  99 /  10  40  20  40
Vicksburg     79 101  78 101 /  10  10  10  20
Hattiesburg   78 101  77  99 /   0  20  20  40
Natchez       78 100  77  99 /   0   0   0  10
Greenville    80 100  77  99 /  10  10  10  20
Greenwood     79  99  77  99 /  10  20  20  30

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...Excessive Heat Warning until 8 PM CDT Friday for MSZ018-019-
     025>029-032>038-040>045-047>051-053>056-059>065-072>074.

     Heat Advisory until 8 PM CDT Friday for MSZ030-031-039-046-052-
     057-058-066.

LA...Excessive Heat Warning until 8 PM CDT Friday for LAZ007>009-015-
     016-023>026.

AR...Excessive Heat Warning until 8 PM CDT Friday for ARZ074-075.

&&

22/10/22

Hazardous Weather Outlook
National Weather Service Jackson MS
318 PM CDT Thu Aug 3 2023

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-034-035-040>043-
047>049-053>055-059>065-072>074-042030-
Ashley-Chicot-Morehouse-West Carroll-East Carroll-Richland-
Madison LA-Franklin LA-Catahoula-Tensas-Concordia-Bolivar-
Sunflower-Washington-Humphreys-Issaquena-Sharkey-Yazoo-Madison MS-
Warren-Hinds-Rankin-Claiborne-Copiah-Simpson-Jefferson-Adams-
Franklin MS-Lincoln-Lawrence-Jefferson Davis-Covington-Marion-
Lamar-Forrest-
318 PM CDT Thu Aug 3 2023

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

.DAY ONE...Tonight and Friday

DANGEROUS HEAT
THREAT...Extreme
TIMING...Friday

Friday, extreme heat stress will continue with peak heat index
values as high as 110 to 120 degrees. Heat stroke and heat
exhaustion will be likely with prolonged outdoor activity.

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

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

Dangerous heat stress will continue with peak heat index values
as high as 110 to 120 degrees Saturday and Sunday. Heat stroke
and heat exhaustion will be possible with prolonged outdoor
activity.

(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.

MSZ028>033-037>039-044>046-050>052-057-058-066-042030-
Montgomery-Webster-Clay-Lowndes-Choctaw-Oktibbeha-Attala-Winston-
Noxubee-Leake-Neshoba-Kemper-Scott-Newton-Lauderdale-Jasper-
Clarke-Jones-
318 PM CDT Thu Aug 3 2023

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

.DAY ONE...Tonight and Friday

SEVERE THUNDERSTORMS
THREAT...Marginal
TIMING...Friday

DANGEROUS HEAT
THREAT...Significant
TIMING...Friday

Friday, isolated severe thunderstorms are possible mainly during
the afternoon. Some thunderstorms could produce damaging wind
gusts.

(https://www.weather.gov/images/jan/graphicast/2.png)

Friday, extreme heat stress will continue with peak heat index
values around 110 degrees. Heat stroke and heat exhaustion will
be likely with prolonged outdoor activity.

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

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

Dangerous heat stress will continue with peak heat index values
as high as 110 to 120 degrees Saturday and Sunday. Heat stroke
and heat exhaustion will be likely with prolonged outdoor
activity.

(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 may be needed for portions of the region Friday
through Friday night.

MSZ025>027-036-042030-
Leflore-Grenada-Carroll-Holmes-
318 PM CDT Thu Aug 3 2023

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

.DAY ONE...Tonight and Friday

SEVERE THUNDERSTORMS
THREAT...Marginal
TIMING...Friday

DANGEROUS HEAT
THREAT...Extreme
TIMING...Friday

Friday, isolated severe thunderstorms are possible mainly during
the afternoon. Some thunderstorms could produce damaging wind
gusts.

(https://www.weather.gov/images/jan/graphicast/2.png)

Friday, extreme heat stress will continue with peak heat index
values as high as 110 to 120 degrees. Heat stroke and heat
exhaustion will be likely with prolonged outdoor activity.

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

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

Dangerous heat stress will continue with peak heat index values
as high as 110 to 120 degrees Saturday and Sunday. Heat stroke
and heat exhaustion will be likely with prolonged outdoor
activity.

(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 may be needed for portions of the region Friday
through Friday night.

MSZ056-042030-
Smith-
318 PM CDT Thu Aug 3 2023

This hazardous weather outlook is for portions of central
Mississippi.

.DAY ONE...Tonight and Friday

DANGEROUS HEAT
THREAT...Significant
TIMING...Friday

Friday, dangerous heat expected with peak heat values in excess
of 110 degrees. Heat stroke will be a significant concern with
outdoor activity.

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

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

Dangerous heat stress will continue with peak heat index values
as high as 110 to 120 degrees Saturday and Sunday. Heat stroke
and heat exhaustion will be likely with prolonged outdoor
activity.

(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.

0

&&

...HAZARD LEGEND...

*DANGEROUS HEAT*
Extreme...Extreme heat is expected with peak heat index values
 in excess of 110 degrees for multiple days. Heat stroke continues
 to be a major concern.
Significant...Dangerous heat expected with peak heat index values
 in excess of 110 degrees. Heat stroke will be a significant
 concern.
Elevated...Dangerous heat likely with peak heat index values
 ranging from 106 to 110 degrees. Heat exhaustion will be likely.
Limited...Caution is advised for possible dangerous heat as
 heat index values peak near 105 degrees. Heat exhaustion will
 be possible.

*SEVERE THUNDERSTORMS*
High...Significant severe thunderstorms and tornadoes are
 likely with strong or violent tornadoes possible.
Moderate...Significant severe thunderstorms and tornadoes are
 likely with strong tornadoes possible.
Enhanced...Severe thunderstorms are likely and tornadoes are
 possible.
Slight...Severe thunderstorms and tornadoes are possible.
Marginal...Isolated severe thunderstorms are possible.

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