Alert archive / Arkansas / Mesoscale Discussions in 2012

Mesoscale Discussion 1893

September 5, 20125 states

The Storm Prediction Center issued this mesoscale discussion at Sep 5, 2012, 2:13 PM CDT for 5 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Sep 5, 2012, 2:13 PM CDT (19:13 UTC)
Expired
Sep 5, 2012, 4:15 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 55 counties

Baxter County, AR, Clay County, AR, Cleburne County, AR, Craighead County, AR, Fulton County, AR, Greene County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Lawrence County, AR, Marion County, AR, Mississippi County, AR, Poinsett County, AR, Randolph County, AR, Sharp County, AR, Stone County, AR, Alexander County, IL, Massac County, IL, Pulaski County, IL, Ballard County, KY, Calloway County, KY, Carlisle County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, Marshall County, KY, McCracken County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, Dunklin County, MO, Howell County, MO, Mississippi County, MO, New Madrid County, MO, Oregon County, MO, Ozark County, MO, Pemiscot County, MO, Ripley County, MO, Scott County, MO, Shannon County, MO, Stoddard County, MO, Wayne County, MO, Carroll County, TN, Crockett County, TN, Dyer County, TN, Gibson County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, Obion County, TN, Weakley County, TN

The radar

The Memphis radar (KNQA), 131 km from the middle of the area, began a volume at 19:16 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

Little Rock, AR (KLZK), launched 12:00Z, 7.2 hours before the alert went out and 186 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 2012-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1178 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 2012-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 square meters per square second.1939Sfc1 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
1178 J/kg
Mixed-layer CIN
-111 J/kg
Mixed-layer LCL
1655 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
18 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.

410 
ACUS11 KWNS 051913
SWOMCD
SPC MCD 051913 
TNZ000-KYZ000-ILZ000-MOZ000-ARZ000-052115-

MESOSCALE DISCUSSION 1893
NWS STORM PREDICTION CENTER NORMAN OK
0213 PM CDT WED SEP 05 2012

AREAS AFFECTED...SRN MO...NERN AR...WRN KY AND TN

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 051913Z - 052115Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...A FEW CLUSTERS OF STRONG TO SEVERE STORMS ARE EXPECTED TO
FORM OVER THE NEXT FEW HOURS FROM SRN MO INTO NRN AR...WITH
LOCALIZED SEVERE HAIL AND WIND.

DISCUSSION...SURFACE MAP SHOWS AN OUTFLOW BOUNDARY ACROSS SRN MO
INTO SRN IL...AND VISIBLE IMAGERY SHOWS SUBSTANTIAL TCU ALONG AND
AHEAD OF THE BOUNDARY WHERE STRONG HEATING PERSISTS. TALL/MOIST CAPE
PROFILES WITH HIGH PRECIPITABLE WATER WILL FAVOR A FEW WET
MICROBURSTS...AND A SOME CELLS MAY PROPAGATE IN A SEWD
DIRECTION...POSSIBLY SHOWING SUPERCELL CHARACTERISTICS AT TIMES WITH
LARGE HAIL OF 1.00" TO 1.75" DIAMETER.

..JEWELL/CORFIDI.. 09/05/2012

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

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

LAT...LON   35518942 35479162 35709237 36339274 36809257 37099211
            37159144 37349051 37438976 37448918 37328864 36878828
            36348812 35958824 35658837 35518942

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 5, 2:29 PM CDTSevere Thunderstorm WatchSPCClay, Craighead, Fulton, Greene, Independence, Izard and 6 more8 hr
Sep 5, 5:31 PM CDTMesoscale DiscussionSPCCrittenden, Cross, Mississippi, Poinsett89 min
Sep 4, 8:30 PM CDTMesoscale DiscussionSPCJo Daviess60 min
Sep 4, 8:51 PM CDTSevere Thunderstorm WatchSPCBoone, Carroll, Cook, DeKalb, DuPage, Grundy and 13 more5 hr
Sep 5, 1:14 AM CDTMesoscale DiscussionSPCCarroll, Henry, Jo Daviess, Rock Island, Stephenson, Whiteside and 1 more91 min
Sep 5, 3:43 AM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, DeKalb, Grundy, Henderson and 21 more92 min
Sep 5, 9:04 AM CDTMesoscale DiscussionSPCAlexander, Bond, Clark, Clay, Clinton, Crawford and 28 more86 min
Sep 5, 9:37 AM CDTSevere Thunderstorm WatchSPCBond, Clark, Clay, Clinton, Coles, Crawford and 24 more6 hr
Sep 5, 1:10 PM CDTMesoscale DiscussionSPCGallatin, Hardin, Johnson, Massac, Pope65 min
Sep 5, 1:43 PM CDTSevere Thunderstorm WatchSPCHardin5 hr
Sep 5, 4:02 PM CDTMesoscale DiscussionSPCBoone, Carroll, Cook, DeKalb, DuPage, Jo Daviess and 7 more88 min

Nearby

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