Alert archive / Missouri / Mesoscale Discussions in 2011

Mesoscale Discussion 151

February 27, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Feb 27, 2011, 4:57 PM CST for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Feb 27, 2011, 4:57 PM CST (22:57 UTC)
Expired
Feb 27, 2011, 7:00 PM CST
In force
2 hr
Issued by
the Storm Prediction Center
All 81 counties

Baxter County, AR, Boone County, AR, Carroll County, AR, Clay County, AR, Cleburne County, AR, Conway County, AR, Franklin County, AR, Fulton County, AR, Greene County, AR, Independence County, AR, Izard County, AR, Johnson County, AR, Lawrence County, AR, Logan County, AR, Madison County, AR, Marion County, AR, Newton County, AR, Pope County, AR, Randolph County, AR, Searcy County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, Washington County, AR, Alexander County, IL, Franklin County, IL, Hardin County, IL, Jackson County, IL, Jefferson County, IL, Johnson County, IL, Massac County, IL, Monroe County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Randolph County, IL, Saint Clair County, IL, Saline County, IL, Union County, IL, Washington County, IL, Williamson County, IL, Ballard County, KY, Carlisle County, KY, Crittenden County, KY, Livingston County, KY, McCracken County, KY, Barry County, MO, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, Christian County, MO, Crawford County, MO, Dent County, MO, Douglas County, MO, Howell County, MO, Iron County, MO, Jefferson County, MO, Laclede County, MO, Madison County, MO, Mississippi County, MO, New Madrid County, MO, Oregon County, MO, Ozark County, MO, Perry County, MO, Phelps County, MO, Pulaski County, MO, Reynolds County, MO, Ripley County, MO, Saint Francois County, MO, Sainte Genevieve County, MO, Scott County, MO, Shannon County, MO, Stoddard County, MO, Stone County, MO, Taney County, MO, Texas County, MO, Washington County, MO, Wayne County, MO, Webster County, MO, Wright County, MO

The radar

The St Louis radar (KLSX), 200 km from the middle of the area, began a volume at 22:57 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 watches that followed

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

The nearest sounding before it

Springfield, MO (KSGF), launched 12:00Z, 11.0 hours before the alert went out and 245 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, Springfield, MO at 12:00Z on 2011-02-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 306 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, Springfield, MO at 12:00Z on 2011-02-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 327 square meters per square second.1939587897117Sfc1 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
306 J/kg
Mixed-layer CIN
-147 J/kg
Mixed-layer LCL
507 m above ground
0-6 km bulk shear
66 kt
0-1 km storm-relative helicity
327 m²/s²
0-3 km storm-relative helicity
349 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

Open this sounding in Storm Lab

The text

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

277 
ACUS11 KWNS 272258
SWOMCD
SPC MCD 272257
KYZ000-ILZ000-MOZ000-TNZ000-ARZ000-280100-

MESOSCALE DISCUSSION 0151
NWS STORM PREDICTION CENTER NORMAN OK
0457 PM CST SUN FEB 27 2011

AREAS AFFECTED...NRN/CNTRL AR...SRN MO...SRN IL...W KY...WRN TN

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 272257Z - 280100Z

TORNADO WATCH WILL LIKELY BE REQUIRED BY EARLY THIS EVENING.  TSTMS
WILL INTENSIFY AROUND 00Z SRN MO/NRN AR AND EXPAND ENE 00-06Z WITH
POSSIBILITY OF TORNADOES /A FEW STRONG/...DAMAGING WINDS AND LARGE
HAIL.

100+ KT H5 JET WAS PUNCHING ACROSS W TX AND WILL TRANSLATE TO THE
OZARKS LATER THIS EVENING WITH A LEAD WAVE MIGRATING ENE THROUGH AR
AT THE MOMENT.  THIS LEAD IMPULSE MAY BE IMPETUS FOR GRADUALLY
INTENSIFYING TSTMS OVER SRN MO/NRN AR BETWEEN 23-00Z...SIMILAR TO
18Z NAM AND 12Z WRF-ARW.  VENTILATION OF INITIAL CELLS WILL FURTHER
INCREASE BY MID-EVENING AS THE PARENT TROUGH APPROACHES.

THE CORRESPONDING INCREASING IN THE SSWLY LOW-LEVEL JET OF 60+ KTS
WILL BOOST VERTICAL SHEAR AND THE LOW-LEVEL SRH WILL BECOME QUITE
STRONG.  ADDITIONALLY...THE LOW LCL/S AND POTENTIAL FOR INITIAL
STORMS TO BE SOMEWHAT DISCRETE WILL POSE A STRONG TORNADO
THREAT...PARTICULARLY ALONG THE AR/MO BORDER.  ACTIVITY SHOULD
TRANSITION TO NE-SW ORIENTED BANDS WITH EMBEDDED BOWS/ROTATING
STRUCTURES AS ACTIVITY DEVELOPS ENE INTO THE LOWER OH VLY BY 06Z.
DAMAGING WINDS...ISOLATED TORNADOES AND LARGE HAIL WILL ALL BE
THREATS.

..RACY.. 02/27/2011

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

ATTN...WFO...PAH...MEG...LSX...LZK...SGF...TSA...

LAT...LON   35869429 37049367 38009201 38349130 38689008 38558902
            38058854 37488793 37038809 36828856 36348998 35709124
            34989267 35089407 35869429

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 27, 12:44 PM CSTMesoscale DiscussionSPCCrittenden, Cross, Lee, Mississippi, St. Francis91 min
Feb 27, 5:10 PM CSTMesoscale DiscussionSPCAdams, Pike35 min
Feb 27, 5:33 PM CSTSevere Thunderstorm WatchSPCAdams, Brown, Cass, DeWitt, Fulton, Logan and 12 more4 hr
Feb 27, 5:50 PM CSTMesoscale DiscussionSPCBureau, Carroll, DeKalb, Henry, Lee, Mercer and 3 more6 hr
Feb 27, 4:31 PM CSTTornado WatchSPCAdair, Allen, Barren, Butler, Casey, Clinton and 11 more3 hr
Feb 27, 12:46 PM CSTMesoscale DiscussionSPCCaldwell, Carroll, Cass, Chariton, Clay, Clinton and 7 more59 min
Feb 27, 1:12 PM CSTSevere Thunderstorm WatchSPCBates, Caldwell, Carroll, Cass, Chariton, Clay and 15 more9 hr
Feb 27, 2:12 PM CSTMesoscale DiscussionSPCBarton, Dade, Jasper, Lawrence, Newton93 min
Feb 27, 3:24 PM CSTMesoscale DiscussionSPCBates, Carroll, Cass, Chariton, Clay, Cooper and 10 more66 min

Nearby

Mesoscale Discussions in Missouri, 2011Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Illinois, 2011Every mesoscale discussion in 2011

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.