Alert archive / Missouri / Mesoscale Discussions in 2012

Mesoscale Discussion 2086

October 23, 2012Carroll County, Arkansas; 15 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Oct 23, 2012, 1:12 AM CDT for Carroll County, Arkansas; 15 counties in Missouri. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Oct 23, 2012, 1:12 AM CDT (06:12 UTC)
Expired
Oct 23, 2012, 3:45 AM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Chance of a watch
5%

Counties Carroll County, AR, Barry County, MO, Benton County, MO, Cedar County, MO, Christian County, MO, Dade County, MO, Dallas County, MO, Greene County, MO, Hickory County, MO, Lawrence County, MO, Pettis County, MO, Polk County, MO, St. Clair County, MO, Stone County, MO, Taney County, MO, Webster County, MO

The radar

The Springfield radar (KSGF), 10 km from the middle of the area, began a volume at 06:15 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

Springfield, MO (KSGF), launched 00:00Z, 6.2 hours before the alert went out and 46 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 00:00Z on 2012-10-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1200 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 00:00Z on 2012-10-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 190 square meters per square second.193958Sfc1 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
1200 J/kg
Mixed-layer CIN
-65 J/kg
Mixed-layer LCL
822 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
190 m²/s²
0-3 km storm-relative helicity
183 m²/s²
Significant tornado parameter
0.8
Supercell composite
2.4

Open this sounding in Storm Lab

The text

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

164 
ACUS11 KWNS 230612
SWOMCD
SPC MCD 230612 
MOZ000-ARZ000-230845-

MESOSCALE DISCUSSION 2086
NWS STORM PREDICTION CENTER NORMAN OK
0112 AM CDT TUE OCT 23 2012

AREAS AFFECTED...PORTIONS W-CENTRAL/SWRN MO.

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 230612Z - 230845Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...CLUSTER OF TSTMS MAY OFFER THREAT FOR DAMAGING GUSTS
THROUGH ABOUT 08Z...ALONG WITH CONDITIONAL/BRIEF TORNADO RISK. 
THREAT APPEARS TOO LOW AND CONFINED IN TIME/SPACE FOR WW.

DISCUSSION...SFC MESOANALYSIS SHOWS WEAK/RESIDUAL/QUASISTATIONARY
FRONTAL ZONE FROM W-CENTRAL MO SSWWD ACROSS NERN AND S-CENTRAL OK. 
THIS FRONT SHOULD CONTINUE TO WEAKEN THROUGH REMAINDER OVERNIGHT
HOURS...BUT WILL DEMARCATE WRN PORTION OF NARROW MOIST PLUME...AXIS
OF WHICH PRECEDES FRONT BY ABOUT 50 NM.  BOUNDARY-LAYER THETAE
DECREASES SUBSTANTIALLY WITH EWD EXTENT THROUGH OZARKS...I.E. SFC
DEW POINTS UPPER 60S F NEAR MOIST AXIS TO MID 50S IN FLP/UNO AREAS. 
TSTMS OVER DISCUSSION AREA HAVE DEVELOPED AS STRONGEST DEEP-LAYER
ASCENT -- ASSOCIATED WITH MID-UPPER LEVEL SHORTWAVE TROUGH NOW
CROSSING WRN MO -- JUXTAPOSES WITH MOIST AXIS...OPTIMIZING BUOYANCY
THAT NONETHELESS IS MRGL.  MODIFIED FCST SOUNDINGS SUGGEST SOME
WEAKENING OF STABLE LAYER BETWEEN 700-850 MB THAT CHARACTERIZED
REGIONAL 00Z RAOBS...PERMITTING EFFECTIVELY SFC-BASED PARCELS NEAR
MOIST AXIS...PRIMARILY OVER SWRN MO.  ABOVE THAT...MLCAPE UP TO 500
J/KG AND MUCAPE 500-1000 J/KG ARE EVIDENT...ALONG WITH LLJ-ENHANCED
EFFECTIVE SRH OF 200-400 J/KG.  RELATIVELY WEAK MIDLEVEL
WINDS...HOWEVER...LIMIT DEEP SHEAR...WITH EFFECTIVE SHEAR MAGNITUDES
ONLY 20-30 KT OVER MOST OF THIS AREA.  

GIVEN THESE MIXED SIGNALS...NET EFFECT SHOULD BE CONTINUATION OF
MESSY AND MOSTLY MULTICELLULAR/CLUSTERED STORM MODES...BUT WITH
POTENTIAL FOR BRIEF/EMBEDDED MESOCYCLONE DEVELOPMENT.  AS PLUME OF
STRONGEST LARGE-SCALE ASCENT SHIFTS NE OF RICHEST NEAR-SFC
MOISTURE...CONVECTION WILL SHIFT EWD AND NEWD ACROSS CENTRAL/SRN MO
AND BECOME MORE ELEVATED IN NATURE.

..EDWARDS/HART.. 10/23/2012

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

ATTN...WFO...LZK...SGF...EAX...TSA...

LAT...LON   36499419 38089381 38869355 38819314 38209291 37379275
            36529277 36269338 36229382 36359410 36499419

Nearby

Mesoscale Discussions in Missouri, 2012Mesoscale Discussions in Arkansas, 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; radar from the NEXRAD Level II archive.