Alert archive / Mississippi / Mesoscale Discussions in 2003

Mesoscale Discussion 970

May 14, 2003Desha County, Phillips County, Arkansas; 34 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at May 14, 2003, 10:26 AM CDT for Desha County, Phillips County, Arkansas; 34 counties in Mississippi. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued
May 14, 2003, 10:26 AM CDT (15:26 UTC)
Expired
May 14, 2003, 12:00 PM CDT
In force
94 min
Issued by
the Storm Prediction Center
All 36 counties

Desha County, AR, Phillips County, AR, Attala County, MS, Bolivar County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, Coahoma County, MS, Grenada County, MS, Holmes County, MS, Humphreys County, MS, Kemper County, MS, Lafayette County, MS, Leake County, MS, Leflore County, MS, Madison County, MS, Montgomery County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Panola County, MS, Quitman County, MS, Scott County, MS, Sharkey County, MS, Sunflower County, MS, Tallahatchie County, MS, Tate County, MS, Tunica County, MS, Washington County, MS, Webster County, MS, Winston County, MS, Yalobusha County, MS, Yazoo County, MS

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Little Rock, AR (KLZK), launched 12:00Z, 3.4 hours before the alert went out and 126 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 2003-05-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 869 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 2003-05-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 66 square meters per square second.1939587897Sfc1 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
869 J/kg
Mixed-layer CIN
-116 J/kg
Mixed-layer LCL
474 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
66 m²/s²
0-3 km storm-relative helicity
88 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.9

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

853 
ACUS11 KWNS 141526
SWOMCD
SPC MCD 141526 
ALZ000-MSZ000-ARZ000-LAZ000-141700-

MESOSCALE DISCUSSION 0970
NWS STORM PREDICTION CENTER NORMAN OK
1026 AM CDT WED MAY 14 2003

AREAS AFFECTED...NRN MS...

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 141526Z - 141700Z

THUNDERSTORMS ACROSS E CENTRAL AR ARE FORECAST TO MOVE SEWD NEAR /
JUST NORTH OF SURFACE FRONT.  DEGREE OF ELEVATED INSTABILITY AND
MARGINAL DEEP-LAYER SHEAR SUGGESTS THAT A LIMITED HAIL THREAT EXISTS
ATTM...WITH AN INCREASE IN SEVERE THREAT OVER THE NEXT 1 TO 3 HOURS.
 NEW WW MAY BE ISSUED IN THE NEXT HOUR ACROSS PARTS OF NRN AND
CENTRAL MS.

LATEST RADAR / SATELLITE IMAGERY SHOWS REMNANTS OF OVERNIGHT MCS /
BROAD COLD POOL ACROSS AR AHEAD OF SHORT WAVE TROUGH MOVING INTO WRN
OK...WITH STRONGEST CLUSTER OF CONVECTION JUST SW OF MEM IN E
CENTRAL AR APPROACHING THE MS RIVER.  SURFACE ANALYSIS SHOWS WARM
FRONT EXTENDING SSEWD FROM THIS CONVECTIVE CLUSTER ACROSS WRN AND
CENTRAL MS TO NEAR GPT...WITH MARGINAL /500 TO 1000 J/KG/
MOST-UNSTABLE CAPE ABOVE STABLE / CAPPED BOUNDARY LAYER.

ALTHOUGH DEEP-LAYER WIND FIELD REMAINS SOMEWHAT WEAK ATTM...
MID-LEVEL FLOW SHOULD INCREASE AS OK SHORT WAVE TROUGH APPROACHES. 
THIS SUGGESTS THAT ONGOING CLUSTER OF STORMS COULD INTENSIFY
SOMEWHAT WITH TIME AS IT MOVES SEWD NEAR / JUST N OF SURFACE
BOUNDARY ACROSS NRN MS.  MAIN SEVERE THREAT WILL LIKELY BE
MARGINALLY-SEVERE HAIL OVER THE NEXT 1 TO 2 HOURS...BUT THREAT FOR
DAMAGING WINDS MAY INCREASE -- PARTICULARLY IF COLD POOL ORGANIZES
INVOF THIS CONVECTION.	SOME THINNING OF CLOUD COVER EVIDENT IN
LATEST SATELLITE IMAGERY MAY ALLOW SUFFICIENT HEATING /
DESTABILIZATION OF BOUNDARY LAYER TO FURTHER ENHANCE POTENTIAL FOR
DAMAGING WINDS IN THE NEXT 2 TO 3 HOURS.

..GOSS.. 05/14/2003

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...BMX...MEG...JAN...LZK...

34869049 34628951 33348838 32458833 32328954 32989112
34149145

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 13, 8:05 PM CDTMesoscale DiscussionSPCColumbia, Hempstead, Lafayette, Miller, Nevada55 min
May 14, 5:50 AM CDTMesoscale DiscussionSPCHoward, Little River, Miller, Sevier115 min
May 14, 10:55 AM CDTMesoscale DiscussionSPCColumbia, Hempstead, Howard, Lafayette, Little River, Miller and 3 more2 hr
May 14, 11:10 AM CDTSevere Thunderstorm WatchSPCPhillips6 hr
May 14, 2:30 PM CDTTornado WatchSPCBradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 10 more6 hr
May 14, 5:17 PM CDTMesoscale DiscussionSPCColumbia, Hempstead, Lafayette, Little River, Miller, Nevada and 1 more118 min
May 14, 6:10 PM CDTSevere Thunderstorm WatchSPCAshley, Columbia, Lafayette, Nevada, Union6 hr
May 14, 2:28 PM CDTMesoscale DiscussionSPCAttala, Carroll, Chickasaw, Choctaw, Clay, Holmes and 18 more62 min

Nearby

Mesoscale Discussions in Mississippi, 2003Mesoscale Discussions in Arkansas, 2003Every mesoscale discussion in 2003

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.