Alert archive / Arkansas / Mesoscale Discussions in 2012

Mesoscale Discussion 300

March 19, 20126 counties in Arkansas; 6 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Mar 19, 2012, 10:17 PM CDT for 6 counties in Arkansas; 6 counties in Missouri. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued: Mar 19, 2012, 10:17 PM CDT (03:17 UTC)
Expired: Mar 19, 2012, 11:15 PM CDT
In force: 58 min
Issued by: the Storm Prediction Center

Counties Baxter County, AR, Boone County, AR, Marion County, AR, Newton County, AR, Pope County, AR, Searcy County, AR, Douglas County, MO, Howell County, MO, Ozark County, MO, Taney County, MO, Texas County, MO, Wright County, MO

The radar

The Springfield radar (KSGF), 92 km from the middle of the area, began a volume at 03:17 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.

Severe Thunderstorm Watch 90Mar 19, 10:35 PM CDT

The nearest sounding before it

Springfield, MO (KSGF), launched 00:00Z, 3.3 hours before the alert went out and 98 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 173 J/kg
Mixed-layer CIN: -17 J/kg
Mixed-layer LCL: 1207 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 221 m²/s²
0-3 km storm-relative helicity: 369 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 3.0

Open this sounding in Storm Lab

The text

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

813 
ACUS11 KWNS 200317
SWOMCD
SPC MCD 200317 
MOZ000-ARZ000-200415-

MESOSCALE DISCUSSION 0300
NWS STORM PREDICTION CENTER NORMAN OK
1017 PM CDT MON MAR 19 2012

AREAS AFFECTED...NCNTRL AR THROUGH SCNTRL MO

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

VALID 200317Z - 200415Z

WW MAY BE NEEDED SOON FOR PARTS OF NCNTRL AR INTO SCNTRL MO AS
STORMS CONTINUE DEVELOPING EWD. DAMAGING WIND IS EXPECTED TO BE THE
PRIMARY THREAT...BUT A COUPLE OF ISOLATED TORNADOES CANNOT BE RULED
OUT.

AN OUTFLOW BOUNDARY EXTENDS FROM NERN MO SWWD THROUGH SWRN MO AND
EXTREME NERN AR THEN SSEWD THROUGH SERN OK. STRONGEST STORMS ARE
DEVELOPING ALONG PORTION OF THE BOUNDARY OVER NWRN AR. THE LINE IS
MOVING EAST AT 25-30 KT. THE DOWNSTREAM WARM SECTOR ONLY MARGINALLY
UNSTABLE WITH 500-1000 J/KG MUCAPE...AND EVENING RAOB DATA FROM
LITTLE ROCK SHOWED A CAPPING INVERSION BASED AROUND 750 MB THAT HAS
LIKELY ADVECTED NWD INTO SRN MO BASED ON MID-LEVEL TRAJECTORIES.
WITH ONSET OF NOCTURNAL COOLING AND PRESENCE OF THE
INVERSION...STORM DEVELOPMENT WILL LIKELY REMAIN CONFINED TO THE
ZONE OF FORCING ALONG THE PROGRESSIVE OUTFLOW BOUNDARY WITH A
DOMINANT LINEAR CONVECTIVE MODE. HOWEVER...LARGE HODOGRAPHS ALONG
THE LLJ AXIS WILL SUPPORT POTENTIAL FOR EMBEDDED ORGANIZED STORMS
INCLUDING OCCASIONAL EMBEDDED SUPERCELL AND BOWING SEGMENTS.

..DIAL.. 03/20/2012

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

ATTN...WFO...LZK...SGF...

LAT...LON   36989315 37629255 37779172 36459186 35249299 35459350
            36139326 36989315

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 19, 7:28 PM CDT	Tornado Watch	SPC	Howard, Little River, Miller, Sevier	9 hr
Mar 19, 8:48 PM CDT	Mesoscale Discussion	SPC	Benton, Carroll, Crawford, Madison, Sebastian, Washington	57 min
Mar 19, 10:35 PM CDT	Severe Thunderstorm Watch	SPC	Baxter, Boone, Marion, Newton, Searcy	3 hr
Mar 20, 1:48 PM CDT	Mesoscale Discussion	SPC	Arkansas, Ashley, Bradley, Calhoun, Cleburne, Cleveland and 22 more	117 min
Mar 20, 2:55 PM CDT	Tornado Watch	SPC	Arkansas, Baxter, Bradley, Calhoun, Cleburne, Cleveland and 25 more	7 hr
Mar 20, 5:57 PM CDT	Mesoscale Discussion	SPC	Arkansas, Fulton, Independence, Izard, Jackson, Monroe and 4 more	93 min

Nearby

Mesoscale Discussions in Arkansas, 2012 Mesoscale Discussions in Missouri, 2012 Every 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.