Severe Thunderstorm Warning 52, NWS Jackson, MS

190 
WWUS54 KJAN 100627
SVSJAN

Severe Weather Statement
National Weather Service Jackson MS
1227 AM CST Mon Feb 10 2020

MSC049-149-100637-
/O.EXP.KJAN.SV.W.0052.000000T0000Z-200210T0630Z/
Warren MS-Hinds MS-
1227 AM CST Mon Feb 10 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN WARREN AND
NORTHWESTERN HINDS COUNTIES WILL EXPIRE AT 1230 AM CST...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.

LAT...LON 3245 9087 3244 9086 3247 9086 3257 9074
      3257 9073 3258 9073 3262 9069 3259 9069
      3259 9066 3255 9065 3255 9059 3253 9058
      3253 9056 3251 9055 3251 9054 3245 9049
      3231 9080 3244 9090
TIME...MOT...LOC 0627Z 235DEG 40KT 3251 9062 

$$

22

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
953 PM CST Sun Feb 9 2020

.UPDATE...
Updated for evening discussion.

&&

.DISCUSSION...
Regional radars showed showers and a few thunderstorms to our
southwest that will spread across the CWA overnight. Widespread
rain is expected over our whole CWA prior to sunrise. None of this
activity is expected to be severe tonight but will start to wet
the ground in advance of stronger storms MOnday. Temperatures were
running a couple degrees warmer than expected but the rain will
knock temperatures down and forecast minimum temperatures still
look on track. /22/

Prior discussion below:

Tonight through early Tuesday morning:

Several rounds of heavy rainfall will lead to widespread flash
flooding, some of which could be significant, across portions of the
ArkLaMiss. Additionally, isolated severe storms with all hazards
will also be possible.

A prolonged period of moist southwest flow will become established
across the region as a closed mid/upper-level low diving through
southern California helps to amplify an upstream longwave mean
trough centered across the Desert Southwest/Four Corners region. At
the same time, a stout 592dam 500mb ridge is progged to be located
between the Yucatan Peninsula and Cuba. The main impetus for this
first round of active weather will be a Pacific shortwave trough
embedded within the southwesterly flow ejecting through northern
Mexico and into the Gulf Coast states. This morning's 12z suite of
hi-res CAM guidance is in general agreement that the associated
upstream showers and thunderstorms over the ArkLaTex will spread
into the area during the early morning hours Monday ahead of an
advancing cold frontal boundary. The forward movement of the
boundary will slow considerably as it becomes oriented parallel to
the southwesterly flow and will essentially stall over central
Mississippi through Tuesday morning, thus setting the stage for
significant flooding.

Flooding threat - Guidance has come into good agreement on a
prolonged period of training convection along the aforementioned
frontal boundary. These storms will reside within an anomalously
moist environment characteristic of 1.75" PWATs in the 99th
percentile and impressive values of deep moisture convergence. The
greatest threat for significant flooding will be along and north of
a line from northern Richland Parish to southern Noxubee County
where rainfall amounts of 4-6" are expected. Locally higher amounts
upwards of 8" will also be possible where the heaviest rain rates
and longest period of training occurs. There will be a rather sharp
southern rainfall gradient with 2-4" along the I-20 corridor and
only 1-2" into the Pine Belt. The limited threat area for flooding
has been trimmed north for this reason. The intial flooding graphic
has been split into two separate graphics as there will be a
distinct lull in the heavy rainfall during the day on Tuesday into
early Wednesday. As such, while the rainfall totals for the first
round of heavy rain are slightly lower, the anticipated impacts
remain the same.

Severe weather - the environment ahead of the frontal boundary will
be unstable with SBCAPE values around 1000 J/kg during peak heating
on Monday. Deep-layer shear of 50-60kts will also be supportive of
organized convective structures. However, the training nature of the
convection will generally preclude a greater severe weather threat.
With that being said, isolated severe weather will be possible with
any portions of the convective line that can remain surface based
and surge into the unstable air without being undercut by cold
pools. Furthermore, hi-res CAM guidance has indicated the potential
for a few storms within the open warm sector ahead of the frontal
boundary but confidence is lower in this scenario. While the threat
is isolated, the respective parameter space is supportive of all
hazards and a marginal risk will be maintained in the HWO/graphics.

Tuesday through Wednesday morning:

A relative lull in the heavy rainfall and storms is expected during
the day on Tuesday through Wednesday morning as the lead Pacific
shortwave trough lifts into the Appalachians and forcing becomes
more nebulous. At least weak isentropic ascent will continue through
the period with showers likely, however. An isolated storm or two
will also be possible across southeastern portions of the area ahead
of the stalled boundary where enough instability could support
updrafts strong enough for charge separation and lightning.
Additional rainfall during the day on Tuesday and into Tuesday night
will generally be 0.25-0.5" and not enough to exacerbate any ongoing
flooding. Will keep the HWO/graphics clear of any hazards during the
Tuesday into Wednesday morning period.

Wednesday afternoon through early Thursday morning:

The second round of heavy rainfall and storms will take place
Wednesday afternoon through early Thursday morning as the primary,
and much stronger, shortwave trough over the Desert Southwest
finally ejects into the Southern Plains and Gulf Coast states. The
GFS has trended into agreement with the ECMWF solution which depicts
surface cyclogenesis across the ArkLaTex on Wednesday morning with
the low lifting northeast into the Ohio River Valley by Thursday
morning. This will allow the stalled frontal boundary to lift back
north as a warm front with the majority of the area residing within
the open warm sector Wednesday afternoon. An early round of
convection will be possible along the warm front Wednesday morning,
but the primary focus will shift to the cold frontal passage
Wednesday afternoon into early Thursday morning.

Flooding threat - another quick 2-3" of rainfall will be possible
with a convective line pushing through the area. Locally higher
amounts will also be possible, especially if the line moves through
slower than anticipated. While 2-3" normally isn't a big problem,
this will be occurring only 24hrs after the first round of
significant rainfall and flooding issues are expected to already be
ongoing. As such, it won't take much rain in a short amount of time
to further exacerbate flooding. PWATs will also remain in the 99th
percentile and convection will reside within an impressive 330-335K
850mb ThetaE ridge, thus further supporting intense rainfall rates.
As previously mentioned, the flooding threat has been separated into
two graphics to highlight the two distinct periods of heavy
rainfall. An elevated threat area has been added for Wednesday into
Thursday for much of the area. The eventual threat level and outlook
area for this second round will be highly dependent on where and how
much rainfall occurs Monday into Tuesday. It's definitely possible
that another significant threat area will be needed for at least
some portion of the area and will be further evaluated.

Severe weather - there's a strong signal in the 12z guidance for a
QLCS to push through the area Wednesday afternoon into early
Thursday. Sufficient instability is progged to reside ahead of the
line with the ECMWF, GFS, and NAM all depicting around 1000 J/kg of
SBCAPE. The environment will also be highly sheared with 60-65kts of
0-6km deep-layer shear, 30kts of 0-1km shear and 200-300 m2/s2 0-1km
SRH. While this parameter space is impressive, further inspection of
the orientation of the shear vectors, particularly at 0-3km and 0-
6km, reveals a boundary parallel orientation. Model QPF fields also
indicate that the QLCS will reside right on or just behind the
frontal boundary itself. This setup strongly favors cold pools
undercutting the QLCS which would greatly inhibit any severe weather
threat. Confidence in severe weather potential remains fairly low at
this point, despite the advertised enhanced risk in the
HWO/graphics. Will maintain consistency and not make any adjustments
to the threat level or area at this point, but barring any major
changes in the guidance its possible that the severe weather threat
will need to be downgraded and the reader is strongly encouraged to
stay tuned to future forecast updates.

Thursday through Sunday:

The shortwave trough axis is expected to lift into the Mid-Atlantic
Thursday with drying conditions for the region. This break in the
active pattern is currently forecast to last at least through
Friday. There are subtle differences in timing, but both GFS and
ECMWF solutions bring yet another storm system into the region next
weekend as a shortwave trough ejects out of the Desert Southwest.
/TW/

&&

.AVIATION...
00Z TAF discussion:
VFR conditions will continue to prevail areawide through 06Z.
After 06Z cigs will begin lowering to MVFR and then to IFR as -RA
and a few TSRA move into the area from the sw. Poor flying
conditions will exist Monday as widespread -RA and occasional TSRA
spread across the area and result IFR conditions prevailing. In
addition, gusty south wind around 20kts will develop over the area
Monday morning as well. /22/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       63  71  60  60 /  73  95  94  60
Meridian      59  71  65  68 /  20  83  78  63
Vicksburg     64  72  54  56 /  99  98 100  59
Hattiesburg   62  73  67  73 /  44  63  45  46
Natchez       64  73  60  62 /  97  80  76  58
Greenville    59  62  45  50 / 100 100 100  60
Greenwood     60  64  48  54 /  94 100 100  56

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...Flash Flood Watch from 6 AM CST Monday through Tuesday afternoon
     for MSZ018-019-025>053.

LA...Flash Flood Watch from 6 AM CST Monday through Tuesday afternoon
     for LAZ007>009-015-016-023>025.

AR...Flash Flood Watch from 6 AM CST Monday through Tuesday afternoon
     for ARZ074-075.

&&

TW/22

Hazardous Weather Outlook
National Weather Service Jackson MS
415 PM CST Sun Feb 9 2020

ARZ074-075-LAZ007>009-015-MSZ018-019-025>042-102215-
Ashley-Chicot-Morehouse-West Carroll-East Carroll-Richland-
Bolivar-Sunflower-Leflore-Grenada-Carroll-Montgomery-Webster-Clay-
Lowndes-Choctaw-Oktibbeha-Washington-Humphreys-Holmes-Attala-
Winston-Noxubee-Issaquena-Sharkey-Yazoo-
415 PM CST Sun Feb 9 2020

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

.DAY ONE...Tonight and Monday

SEVERE THUNDERSTORMS
THREAT...Marginal
TIMING...Monday

FLOODING
THREAT...Significant
TIMING...Monday

Isolated severe thunderstorms are possible. Some thunderstorms
could produce damaging wind gusts. A tornado cannot be ruled out.

(https://www.weather.gov/images/jan/graphicast/3.png)

Widespread flash flooding is likely and significant flooding is
possible. Many roads could be flooded or closed and some
structural flooding and water rescues are likely. Moderate to
major river flooding will also be likely.

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

.DAYS TWO THROUGH SEVEN...Monday night through Saturday

Flooding is expected again Wednesday as heavy rain pushes through
the area with a cold front. The additional heavy rain amounts
over already saturated soils may lead to more widespread flash
flooding.

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

Severe thunderstorms will be possible throughout the ArkLaMiss on
Wednesday into Wednesday night as the cold front sweeps through
the region. Damaging wind gusts, tornadoes, and large hail will
all be possible.

(https://www.weather.gov/images/jan/graphicast/4.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 Monday
through Monday night and Wednesday through Wednesday night.

LAZ016-023-025-MSZ043>054-056-102215-
Madison LA-Franklin LA-Tensas-Madison MS-Leake-Neshoba-Kemper-
Warren-Hinds-Rankin-Scott-Newton-Lauderdale-Claiborne-Copiah-
Smith-
415 PM CST Sun Feb 9 2020

This hazardous weather outlook is for portions of northeast
Louisiana, central Mississippi, and southwest Mississippi.

.DAY ONE...Tonight and Monday

SEVERE THUNDERSTORMS
THREAT...Marginal
TIMING...Monday

FLOODING
THREAT...Elevated
TIMING...Monday

Isolated severe thunderstorms are possible. Some thunderstorms
could produce damaging wind gusts. A tornado cannot be ruled out.

(https://www.weather.gov/images/jan/graphicast/3.png)

Areas of flash flooding likely and some roads could be flooded or
closed. Some structures may be potentially threatened by high
water. Minor river flooding is also possible.

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

.DAYS TWO THROUGH SEVEN...Monday night through Saturday

Flooding is expected again Wednesday as heavy rain pushes through
the area with a cold front. The additional heavy rain amounts
over already saturated soils may lead to more widespread flash
flooding.

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

Severe thunderstorms will be possible throughout the ArkLaMiss on
Wednesday into Wednesday night as the cold front sweeps through
the region. Damaging wind gusts, tornadoes, and large hail will
all be possible.

(https://www.weather.gov/images/jan/graphicast/4.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 Monday
through Monday night and Wednesday through Wednesday night.

LAZ024-026-MSZ055-057-059>062-102215-
Catahoula-Concordia-Simpson-Jasper-Jefferson-Adams-Franklin MS-
Lincoln-
415 PM CST Sun Feb 9 2020

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

.DAY ONE...Tonight and Monday

SEVERE THUNDERSTORMS
THREAT...Marginal
TIMING...Monday

FLOODING
THREAT...Limited
TIMING...Monday

Isolated severe thunderstorms are possible. Some thunderstorms
could produce damaging wind gusts. A tornado cannot be ruled out.

(https://www.weather.gov/images/jan/graphicast/3.png)

Localized flash flooding is possible, particularly in low lying
and urban areas. Minor river flooding is also possible.

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

.DAYS TWO THROUGH SEVEN...Monday night through Saturday

Flooding is expected again Wednesday as heavy rain pushes through
the area with a cold front. The additional heavy rain amounts
over already saturated soils may lead to more widespread flash
flooding.

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

Severe thunderstorms will be possible throughout the ArkLaMiss on
Wednesday into Wednesday night as the cold front sweeps through
the region. Damaging wind gusts, tornadoes, and large hail will
all be possible.

(https://www.weather.gov/images/jan/graphicast/4.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 Monday
through Monday night and Wednesday through Wednesday night.

MSZ058-063-065-102215-
Clarke-Lawrence-Covington-
415 PM CST Sun Feb 9 2020

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

.DAY ONE...Tonight and Monday

FLOODING
THREAT...Limited
TIMING...Monday

Localized flash flooding is possible, particularly in low lying
and urban areas. Minor river flooding is also possible.

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

.DAYS TWO THROUGH SEVEN...Monday night through Saturday

Flooding is expected again Wednesday as heavy rain pushes through
the area with a cold front. The additional heavy rain amounts
over already saturated soils may lead to more flash flooding.

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

Severe thunderstorms will be possible throughout the ArkLaMiss on
Wednesday into Wednesday night as the cold front sweeps through
the region. Damaging wind gusts, tornadoes, and large hail will
all be possible.

(https://www.weather.gov/images/jan/graphicast/4.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 Wednesday
through Wednesday night.

MSZ064-066-072>074-102215-
Jefferson Davis-Jones-Marion-Lamar-Forrest-
415 PM CST Sun Feb 9 2020

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

.DAY ONE...Tonight and Monday

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Monday night through Saturday

Flooding is expected Wednesday as heavy rain pushes through the
area with a cold front. The heavy rain amounts over already
saturated soils may lead to flash flooding.

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

Severe thunderstorms will be possible throughout the ArkLaMiss on
Wednesday into Wednesday night as the cold front sweeps through
the region. Damaging wind gusts, tornadoes, and large hail will
all be possible.

(https://www.weather.gov/images/jan/graphicast/4.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 Wednesday
through Wednesday night.

26

&&

...HAZARD LEGEND...

*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.

*FLOODING*
Extreme...Widespread and significant flooding is likely.
Significant...Widespread flash flooding is likely
 and significant flooding is possible.
Elevated...Areas of flash flooding likely.
Limited...Localized flash flooding is possible.

...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

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

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

Storm Prediction Center (SPC)...
   https://www.spc.noaa.gov/
Meso Analysis...
   https://www.spc.noaa.gov/exper/mesoanalysis/
Day 1 through 3 Outlooks...
   https://www.spc.noaa.gov/products/outlook/
Storm Reports...
   https://www.spc.noaa.gov/climo/online/
...ADDITIONAL URLS FOR FLOODING ISSUES...

Current Watches and Warnings...
   https://www.weather.gov/jan/safe_HeavyRain

Observed Precipitation Images...
   https://www.weather.gov/jan/precipmaps

River Forecast Center...
   https://www.weather.gov/lmrfc/
Significant River Flood Outlook...
   https://www.wpc.ncep.noaa.gov/nationalfloodoutlook/index.html
Day 1 through 3 Excessive Rainfall...
   https://www.wpc.ncep.noaa.gov/qpf/excess_rain.shtml
Excessive Rainfall Discussion...
   https://www.wpc.ncep.noaa.gov/discussions/qpferd.html
Day 1 through 7 QPF...
   https://www.wpc.ncep.noaa.gov/qpf/qpf2.shtml
QPF Discussion...
   https://www.wpc.ncep.noaa.gov/discussions/qpfpfd.html

Special Weather Statement
National Weather Service Jackson MS
1106 PM CST Sun Feb 9 2020

LAZ016-023-025-MSZ047-053-100600-
Tensas LA-Madison LA-Franklin LA-Warren MS-Claiborne MS-
1106 PM CST Sun Feb 9 2020

...A STRONG THUNDERSTORM WILL AFFECT TENSAS...CENTRAL MADISON AND
SOUTHEASTERN FRANKLIN PARISHES...SOUTHWESTERN WARREN AND NORTHERN
CLAIBORNE COUNTIES UNTIL MIDNIGHT CST...

At 1105 PM CST, Meteorologists were tracking a strong thunderstorm
near Cooter Point, or 18 miles southeast of Winnsboro, moving
northeast at 45 mph.

Nickel size hail and wind gusts up to 50 mph will be possible with
this storm.

This strong thunderstorm will be near...
  Newlight around 1110 PM CST.
  Lake Bruin around 1120 PM CST.
  Newellton around 1125 PM CST.
  Somerset around 1130 PM CST.
  Afton around 1135 PM CST.
  Vicksburg, Le Tourneau and Yokena around 1150 PM CST.

Other locations impacted by this storm include Mound and Delta.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

High winds can bring down trees and large limbs resulting in serious
injury or property damage. Exercise extreme caution when outdoors
during such strong winds...and be especially aware of older trees.

&&

LAT...LON 3186 9144 3212 9166 3246 9100 3214 9075
TIME...MOT...LOC 0505Z 238DEG 39KT 3201 9145

JM