Alert archive / Missouri / Mesoscale Discussions in 2012

Mesoscale Discussion 1899

September 6, 20129 counties in Arkansas; 46 counties in Missouri; Ottawa County, Oklahoma

The Storm Prediction Center issued this mesoscale discussion at Sep 6, 2012, 10:52 AM CDT for 9 counties in Arkansas; 46 counties in Missouri; Ottawa County, Oklahoma. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued
Sep 6, 2012, 10:52 AM CDT (15:52 UTC)
Expired
Sep 6, 2012, 12:15 PM CDT
In force
83 min
Issued by
the Storm Prediction Center
All 56 counties

Baxter County, AR, Benton County, AR, Boone County, AR, Carroll County, AR, Clay County, AR, Fulton County, AR, Marion County, AR, Randolph County, AR, Sharp County, AR, Barry County, MO, Barton County, MO, Bollinger County, MO, Butler County, MO, Camden County, MO, Carter County, MO, Cedar County, MO, Christian County, MO, Crawford County, MO, Dade County, MO, Dallas County, MO, Dent County, MO, Douglas County, MO, Greene County, MO, Hickory County, MO, Howell County, MO, Iron County, MO, Jasper County, MO, Jefferson County, MO, Laclede County, MO, Lawrence County, MO, Madison County, MO, Maries County, MO, McDonald County, MO, Miller County, MO, Newton County, MO, Oregon County, MO, Ozark County, MO, Phelps County, MO, Polk County, MO, Pulaski County, MO, Reynolds County, MO, Ripley County, MO, Saint Francois County, MO, Sainte Genevieve County, MO, Shannon County, MO, St. Clair County, MO, Stoddard County, MO, Stone County, MO, Taney County, MO, Texas County, MO, Vernon County, MO, Washington County, MO, Wayne County, MO, Webster County, MO, Wright County, MO, Ottawa County, OK

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, 3.9 hours before the alert went out and 157 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 2012-09-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 841 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 2012-09-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 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
841 J/kg
Mixed-layer CIN
-167 J/kg
Mixed-layer LCL
1845 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
10 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

The text

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

173 
ACUS11 KWNS 061552
SWOMCD
SPC MCD 061552 
MOZ000-ILZ000-ARZ000-OKZ000-KSZ000-061715-

MESOSCALE DISCUSSION 1899
NWS STORM PREDICTION CENTER NORMAN OK
1052 AM CDT THU SEP 06 2012

AREAS AFFECTED...SRN MO...FAR NRN AR

CONCERNING...OUTLOOK UPGRADE 

VALID 061552Z - 061715Z

SUMMARY...SMALL TSTM CLUSTER NEAR KS/MO BORDER MAY GROW UPSCALE AS
IT PROGRESSES INTO AN INCREASINGLY UNSTABLE AIR MASS. THIS AREA WILL
BE UPGRADED TO SLIGHT RISK WITH THE 1630Z DAY 1 OUTLOOK AND IS BEING
MONITORED FOR A POSSIBLE SEVERE TSTM WATCH ISSUANCE.

DISCUSSION...SMALL TSTM CLUSTER CENTERED OVER BOURBON COUNTY KS MAY
INCREASE IN COVERAGE/INTENSITY AS DOWNSTREAM SURFACE TEMPERATURES
WARMS THROUGH THE 80S INTO THE 90S AMIDST PW VALUES APPROACHING 1.5
INCHES. THIS SHOULD YIELD MODERATELY LARGE BUOYANCY WITH MLCAPE
LIKELY INCREASING TO NEAR 2500 J/KG BY MID-AFTERNOON. PRESENCE OF A
WEAK CYCLONE NEAR THE KS/OK/MO BORDER AND REMNANT QUASI-STATIONARY
FRONTAL ZONE DRAPED ACROSS SRN MO MAY FOSTER CONGLOMERATING UPDRAFTS
AND YIELD UPSCALE GROWTH...PER RECENT HRRR GUIDANCE. WEAK ELY
COMPONENT TO SURFACE FLOW AMIDST MODEST MID-LEVEL W/NWLYS SHOULD BE
SUFFICIENT FOR SEMI-ORGANIZED CLUSTERS WITH A PRIMARY THREAT OF
ISOLATED DAMAGING WINDS.

..GRAMS/CORFIDI.. 09/06/2012

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

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

LAT...LON   38109411 38379228 38409135 38259042 38119004 37468972
            36868977 36508998 36159047 36109155 36159361 36289445
            36839486 37649476 38109411

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 6, 3:37 PM CDTMesoscale DiscussionSPCClay, Randolph83 min
Sep 6, 6:29 PM CDTMesoscale DiscussionSPCBaxter, Boone, Carroll, Clay, Fulton, Greene and 3 more91 min
Sep 6, 12:28 PM CDTSevere Thunderstorm WatchSPCBarry, Benton, Bollinger, Butler, Camden, Cape Girardeau and 46 more9 hr
Sep 6, 2:03 PM CDTMesoscale DiscussionSPCBollinger, Butler, Callaway, Cape Girardeau, Carter, Cole and 32 more57 min
Sep 6, 3:10 PM CDTMesoscale DiscussionSPCBeaver, Cimarron, Texas3 hr

Nearby

Mesoscale Discussions in Missouri, 2012Mesoscale Discussions in Arkansas, 2012Mesoscale Discussions in Oklahoma, 2012Every mesoscale discussion in 2012

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.