Alert archive / Mississippi / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 217, NWS Memphis, TN

August 18, 2015Calhoun County, Chickasaw County, Mississippi

NWS Memphis, TN issued this severe thunderstorm warning at Aug 18, 2015, 5:36 PM CDT for Calhoun County, Chickasaw County, Mississippi. It was in force for 39 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
Aug 18, 2015, 5:36 PM CDT (22:36 UTC)
Expired
Aug 18, 2015, 6:15 PM CDT
In force
39 min
Issued by
NWS Memphis, TN
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Calhoun County, MS, Chickasaw County, MS

The radar

The Columbus AFB radar (KGWX), 75 km from the middle of the area, began a volume at 22:36 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

Little Rock, AR (KBYH), launched 12:00Z, 10.6 hours before the alert went out and 125 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, Little Rock, AR at 12:00Z on 2015-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 425 joules per kilogram.LCLLFCEL10008507005003002001001 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, Little Rock, AR at 12:00Z on 2015-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 square meters per square second.1939Sfc1 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
425 J/kg
Mixed-layer CIN
-73 J/kg
Mixed-layer LCL
1076 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
32 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 Aug 18, 3:38 PM CDT, 1 hour 58 minutes earlier.

Area forecast discussion, Aug 18, 3:38 PM CDT, 1 hour 58 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
338 PM CDT TUE AUG 18 2015

.DISCUSSION...WATER VAPOR SATELLITE/WSR-88D VAD WIND PROFILES THIS
AFTERNOON INDICATE A SUBTLE MID LEVEL SHORTWAVE MOVING THROUGH THE
LOWER MISSISSIPPI VALLEY. AS A RESULT...SCATTERED SHOWERS AND
THUNDERSTORMS HAVE DEVELOPED ACROSS THE MID SOUTH WITH THE
GREATEST COVERAGE ACROSS NORTH MISSISSIPPI. AS OF 3 PM
CDT...TEMPERATURES ACROSS THE MID SOUTH ARE IN THE UPPER 80S TO
LOWER 90S ACROSS MOST AREAS WHERE RAIN HASN/T OCCURRED JUST YET.

A WEAK SUBTLE MID LEVEL SHORTWAVE WILL MOVE ACROSS THE MID SOUTH
FOR THE REMAINDER OF THE AFTERNOON INTO THIS EVENING. OVERALL
FORCING REMAINS WEAK AND CONVECTION IS BEING PREDOMINANTLY DRIVEN
BY DAYTIME HEATING. CONSEQUENTLY...ANTICIPATING OVERALL COVERAGE
TO DIMINISH SOMEWHAT TOWARDS SUNSET.

SHORT TERM MODEL TRENDS CONTINUE TO INDICATE WEAKENING MID LEVEL
HEIGHTS ACROSS THE MID SOUTH AS AN UPPER LEVEL TROUGH MOVES ACROSS
THE UPPER AND MIDDLE MISSISSIPPI VALLEYS WEDNESDAY INTO WEDNESDAY
NIGHT. AT THE SURFACE...A COLD FRONT OVER THE MIDDLE/UPPER
MISSISSIPPI VALLEYS IS EXPECTED TO DROP INTO THE MID SOUTH
WEDNESDAY NIGHT INTO THURSDAY. THIS WILL RESULT IN INCREASED
CHANCES FOR SHOWERS AND THUNDERSTORMS WEDNESDAY INTO WEDNESDAY
NIGHT WITH RAIN CHANCES GRADUALLY SHIFTING MAINLY ALONG AND SOUTH
OF I-40 ON THURSDAY. BEST FORCING/KINEMATICS WILL REMAIN TO THE
NORTH OF THE REGION WITH ANY CONVECTION BEING DRIVEN PREDOMINANTLY
BY THERMODYNAMICS. 0-6 KM SHEAR VALUES AROUND 35 KTS SUPPORT SOME
ORGANIZATION AND PERHAPS A POTENTIAL FOR STRONG TO SEVERE
THUNDERSTORMS ESPECIALLY WEDNESDAY AFTERNOON INTO WEDNESDAY
EVENING.

THE AFOREMENTIONED FRONT IS EXPECTED TO PUSH BACK NORTH OF THE
AREA FRIDAY INTO SATURDAY WITH SHOWER AND THUNDERSTORM CHANCES
INCREASING AGAIN...FOLLOWED BY ANOTHER PASSAGE OF A FRONT LATE FOR
THE UPCOMING WEEKEND.

CJC

&&

.AVIATION...
18Z TAFS

DEEP SOUTHERLY TROPICAL FLOW WILL PREVAIL THROUGH THE NEXT 24
HOURS. BEST SHRA/TSRA CHANCES WILL REMAIN NEAR TUP. WEDNESDAY
MORNING WILL LIKELY SEE AN EXPANSION OF SHRA/TSRA CHANCES WITH
DAYTIME HEATING AND THE APPROACH OF A MIDLEVEL TROF.

PWB

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
Hazardous weather outlook, Aug 18, 3:40 PM CDT, 1 hour 56 minutes before
HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE MEMPHIS TN
340 PM CDT TUE AUG 18 2015

ARZ008-009-017-018-026>028-035-036-048-049-058-MOZ113-115-
MSZ001>017-020>024-TNZ001>004-019>022-048>055-088>092-191045-
ALCORN-BENTON MS-BENTON TN-CALHOUN-CARROLL-CHESTER-CHICKASAW-CLAY-
COAHOMA-CRAIGHEAD-CRITTENDEN-CROCKETT-CROSS-DESOTO-DECATUR-
DUNKLIN-DYER-FAYETTE-GIBSON-GREENE-HARDEMAN-HARDIN-HAYWOOD-
HENDERSON-HENRY-ITAWAMBA-LAFAYETTE-LAKE-LAUDERDALE-LAWRENCE-
LEE AR-LEE MS-MADISON-MARSHALL-MCNAIRY-MISSISSIPPI-MONROE-OBION-
PANOLA-PEMISCOT-PHILLIPS-POINSETT-PONTOTOC-PRENTISS-QUITMAN-
RANDOLPH-SHELBY-ST. FRANCIS-TALLAHATCHIE-TATE-TIPPAH-TIPTON-
TISHOMINGO-TUNICA-UNION-WEAKLEY-YALOBUSHA-
340 PM CDT TUE AUG 18 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST ARKANSAS...
THE MISSOURI BOOTHEEL...NORTH MISSISSIPPI...AND WEST TENNESSEE.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF THE
MID SOUTH ON WEDNESDAY...ESPECIALLY WEDNESDAY AFTERNOON INTO
WEDNESDAY EVENING. DAMAGING WINDS WILL BE THE PRIMARY THREAT FOR ANY
THUNDERSTORMS WHICH REACH SEVERE LIMITS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED WEDNESDAY AFTERNOON INTO WEDNESDAY
EVENING.

In the hours before

Special weather statement, Aug 18, 4:03 PM CDT, 1 hour 33 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MEMPHIS TN
403 PM CDT TUE AUG 18 2015

MSZ001-002-008-TNZ088-089-182130-
TATE MS-MARSHALL MS-DESOTO MS-FAYETTE TN-SHELBY TN-
403 PM CDT TUE AUG 18 2015

...THE NATIONAL WEATHER SERVICE IN MEMPHIS HAS ISSUED A SIGNIFICANT
WEATHER ADVISORY UNTIL UNTIL 430 PM CDT FOR...

NORTH CENTRAL TATE COUNTY IN NORTHWESTERN MISSISSIPPI...
NORTHWESTERN MARSHALL COUNTY IN NORTHWESTERN MISSISSIPPI...
EASTERN DESOTO COUNTY IN NORTHWESTERN MISSISSIPPI...
SOUTHERN FAYETTE COUNTY IN WEST TENNESSEE...
SOUTHEASTERN SHELBY COUNTY IN WEST TENNESSEE...

AT 403 PM CDT...A STRONG THUNDERSTORM PRODUCING PEA SIZE HAIL OR
LARGER AND WINDS AT LEAST 40 MPH WAS LOCATED NEAR BYHALIA...OR 10
MILES SOUTHEAST OF OLIVE BRANCH...MOVING NORTHEAST AT 25 MPH.

VERY HEAVY RAIN ALONG WITH CONTINUOUS CLOUD TO GROUND LIGHTNING ARE
ALSO POSSIBLE WITH THIS THUNDERSTORM.

PEOPLE IN NORTH CENTRAL TATE...NORTHWESTERN MARSHALL...EASTERN
DESOTO...SOUTHERN FAYETTE AND SOUTHEASTERN SHELBY COUNTIES SHOULD
MONITOR THIS STORM CLOSELY.

LAT...LON 3477 8963 3474 8995 3513 8989 3508 8927
TIME...MOT...LOC 2103Z 213DEG 24KT 3482 8975
Special weather statement, Aug 18, 4:51 PM CDT, 45 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MEMPHIS TN
451 PM CDT TUE AUG 18 2015

MSZ015-022>024-182230-
CALHOUN MS-CHICKASAW MS-PONTOTOC MS-MONROE MS-
451 PM CDT TUE AUG 18 2015

...THE NATIONAL WEATHER SERVICE IN MEMPHIS HAS ISSUED A SIGNIFICANT
WEATHER ADVISORY UNTIL UNTIL 530 PM CDT FOR...

CALHOUN COUNTY IN NORTHEASTERN MISSISSIPPI...
CHICKASAW COUNTY IN NORTHEASTERN MISSISSIPPI...
SOUTHERN PONTOTOC COUNTY IN NORTHEASTERN MISSISSIPPI...
NORTHWESTERN MONROE COUNTY IN NORTHEASTERN MISSISSIPPI...

AT 451 PM CDT...A STRONG THUNDERSTORM PRODUCING PEA SIZE HAIL OR
LARGER AND WINDS AT LEAST 40 MPH WAS LOCATED NEAR BRUCE...OR 17 MILES
SOUTHEAST OF WATER VALLEY...MOVING EAST AT 25 MPH.

VERY HEAVY RAIN ALONG WITH CONTINUOUS CLOUD TO GROUND LIGHTNING ARE
ALSO POSSIBLE WITH THIS THUNDERSTORM.

PEOPLE IN CALHOUN...CHICKASAW...SOUTHERN PONTOTOC AND NORTHWESTERN
MONROE COUNTIES SHOULD MONITOR THIS STORM CLOSELY.

LAT...LON 3415 8950 3414 8882 3408 8882 3408 8872
      3409 8872 3409 8871 3381 8872 3381 8893
      3375 8893 3375 8903 3374 8904 3372 8950
TIME...MOT...LOC 2151Z 272DEG 20KT 3404 8935
Special weather statement, Aug 18, 5:32 PM CDT, 4 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Aug 18, 4:03 PM CDTSpecial Weather StatementMEGMarshall27 min
Aug 18, 4:51 PM CDTSpecial Weather StatementMEGCalhoun, Chickasaw39 min
Aug 18, 5:10 PM CDTSevere Thunderstorm WarningMEGChickasaw32 min
Aug 18, 5:32 PM CDTSpecial Weather StatementMEGMonroe28 min

Nearby

Severe Thunderstorm Warnings in Mississippi, 2015Every severe thunderstorm warning in 2015

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.