Alert archive / Mississippi / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 203, NWS Memphis, TN

July 12, 2020Alcorn County, Tishomingo County, Mississippi; Hardin County, McNairy County, Tennessee

NWS Memphis, TN issued this severe thunderstorm warning at Jul 12, 2020, 9:38 AM CDT for Alcorn County, Tishomingo County, Mississippi; Hardin County, McNairy County, Tennessee. It was in force for 52 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 12, 2020, 9:38 AM CDT (14:38 UTC)
Expired
Jul 12, 2020, 10:30 AM CDT
In force
52 min
Issued by
NWS Memphis, TN
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Alcorn County, MS, Tishomingo County, MS, Hardin County, TN, McNairy County, TN

The radar

The Columbus AFB radar (KGWX), 123 km from the middle of the area, began a volume at 14:42 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 2.6 hours before the alert went out and 205 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Nashville Metro, TN at 12:00Z on 2020-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Nashville Metro, TN at 12:00Z on 2020-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 188 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
852 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
188 m²/s²
0-3 km storm-relative helicity
332 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Memphis, TN wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 12, 6:35 AM CDT, 3 hours 3 minutes earlier.

Area forecast discussion, Jul 12, 6:35 AM CDT, 3 hours 3 minutes before
Area Forecast Discussion
National Weather Service Memphis TN
635 AM CDT Sun Jul 12 2020

.UPDATE...
Updated 12z Aviation Discussion.

&&

.PREV DISCUSSION... /issued 312 AM CDT Sun Jul 12 2020/

DISCUSSION...

SKies are mostly clear across the Mid-South early this morning
with temperatures ranging from the mid 70s to lower 80s. An area
of thunderstorms has been moving across portions of western
Kentucky and has begun to move into middle Tennessee. In addition,
a weak frontal boundary extends across southern Missouri through
northwest Oklahoma and into southeast New Mexico.

The frontal boundary will drop further south into the Mid-South.
This front will provide a focus for additional thunderstorm
development later today. Temperatures will be a little cooler
today with this boundary moving into the region with highs in the
upper 80s to around 90. With slightly cooler temperatures expected
today, heat index values should remain around 100 degrees this
afternoon so a Heat Advisory is not needed at this time.

The frontal boundary will continue to push south into north
Mississippi tonight with any thunderstorms that develop confined
to southern sections of the Mid-South. Temperatures will be
seasonally warm tonight with lows Monday morning in the upper 60s
to lower 70s.

By Monday, high pressure will build into the region bringing dry
weather to the Mid-South. Temperatures will be a little warmer on
Monday with highs in the upper 80s to lower 90s. Heat index values
should remain around 100 degrees on Monday. High pressure will
remain over the region on Tuesday bringing another day of dry
weather. Temperatures will be even warmer on Tuesday with highs in
the low to mid 90s. In addition, heat index values should exceed
105 degrees over southern and western sections of the Mid-South so
a Heat Advisory may be needed.

By Wednesday, a new cold front will move into Missouri. Some of
the thunderstorms that develop ahead of this front may reach
northern and eastern sections of the Mid-South Wednesday or
Wednesday night. The front will remain stalled out over central
Missouri on Thursday and Friday with a few thunderstorms possibly
reaching the Mid- South during the late morning or afternoon
hours both days.

By Saturday, the frontal boundary will have fallen apart leaving
the Mid-South dry. Temperatures will remain on the hot side from
Wednesday through Saturday with afternoon highs in the mid 90s.
Heat index values across the much of the Mid-South will be in the
105-110 range each day.

ARS

&&

.AVIATION...
/12z TAFs/
Made some big changes to the 06z TAF set. Short range models
indicate TSRA not really affecting the TAF sites, so have taken
out the TEMPO group. There's still a chance for shower development
at each TAF site so still have VCSH through the morning. TUP has
the best chance for seeing TSRA but confidence is low. The other
change made was to winds. Winds will begin to gust to 16/15kts
later this afternoon and persist through the evening. They will
quickly become calm around 01z.

SGW

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
Hazardous weather outlook, Jul 12, 8:59 AM CDT, 39 minutes before
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In the hours before

Special weather statement, Jul 12, 9:04 AM CDT, 34 minutes before
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Local storm report, Jul 12, 9:05 AM CDT, 33 minutes before
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Special weather statement, Jul 12, 9:15 AM CDT, 23 minutes before
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Local storm report, Jul 12, 9:26 AM CDT, 12 minutes before
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Local storm report, Jul 12, 9:32 AM CDT, 6 minutes before
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Local storm report, Jul 12, 9:33 AM CDT, 5 minutes before
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The office that day

Everything else NWS Memphis, TN issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 12, 7:02 AM CDTSpecial Weather StatementMEGCalhoun13 min
Jul 12, 7:16 AM CDTSpecial Weather StatementMEGCalhoun29 min
Jul 12, 10:18 AM CDTSpecial Weather StatementMEGAlcorn27 min
Jul 12, 10:28 AM CDTSpecial Weather StatementMEGPrentiss, Tishomingo32 min
Jul 12, 10:58 AM CDTSpecial Weather StatementMEGItawamba, Lee, Prentiss, Tishomingo47 min
Jul 12, 11:03 AM CDTSpecial Weather StatementMEGBenton, Tippah, Union42 min
Jul 12, 11:44 AM CDTSpecial Weather StatementMEGItawamba, Lee31 min
Jul 12, 12:13 PM CDTSpecial Weather StatementMEGChickasaw, Itawamba, Lee, Monroe, Pontotoc32 min
Jul 12, 12:41 PM CDTSpecial Weather StatementMEGMonroe34 min
Jul 12, 6:17 AM CDTSpecial Weather StatementMEGBenton, Henry28 min
Jul 12, 6:54 AM CDTSpecial Weather StatementMEGBenton, Henry, Weakley36 min
Jul 12, 6:56 AM CDTSpecial Weather StatementMEGDecatur, Henderson34 min
Jul 12, 6:58 AM CDTSpecial Weather StatementMEGDyer, Lake32 min
Jul 12, 7:29 AM CDTSpecial Weather StatementMEGBenton, Henry, Weakley46 min
Jul 12, 7:38 AM CDTSpecial Weather StatementMEGGibson, Lake, Obion37 min
Jul 12, 7:54 AM CDTSpecial Weather StatementMEGHardin51 min
Jul 12, 8:02 AM CDTAreal Flood AdvisoryMEGBenton, Henry, Weakley3 hr
Jul 12, 8:22 AM CDTAreal Flood AdvisoryMEGBenton, Carroll, Decatur, Gibson, Henderson, Henry and 2 more3 hr
Jul 12, 8:26 AM CDTFlash Flood WarningMEGBenton, Carroll, Henry, Weakley3 hr
Jul 12, 8:32 AM CDTSpecial Weather StatementMEGCarroll, Decatur, Henderson43 min
Jul 12, 8:41 AM CDTSevere Thunderstorm WarningMEGCarroll, Chester, Decatur, Henderson, Madison34 min
Jul 12, 9:04 AM CDTSpecial Weather StatementMEGChester, Madison26 min
Jul 12, 9:15 AM CDTSpecial Weather StatementMEGHardin, McNairy45 min
Jul 12, 10:40 AM CDTAreal Flood AdvisoryMEGHardin2 hr
Jul 12, 6:51 PM CDTSpecial Weather StatementMEGBenton24 min
Jul 12, 6:20 AM CDTSpecial Weather StatementMEGClay25 min

Nearby

Severe Thunderstorm Warnings in Mississippi, 2020Severe Thunderstorm Warnings in Tennessee, 2020Every severe thunderstorm warning in 2020

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.