Alert archive / South Dakota / Mesoscale Discussions in 2012

Mesoscale Discussion 363

March 26, 20125 states

The Storm Prediction Center issued this mesoscale discussion at Mar 26, 2012, 2:56 PM MDT for 5 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Mar 26, 2012, 2:56 PM MDT (20:56 UTC)
Expired
Mar 26, 2012, 5:00 PM MDT
In force
2 hr
Issued by
the Storm Prediction Center

Counties Carter County, MT, Adams County, ND, Bowman County, ND, Dawes County, NE, Bennett County, SD, Butte County, SD, Custer County, SD, Fall River County, SD, Haakon County, SD, Harding County, SD, Jackson County, SD, Lawrence County, SD, Meade County, SD, Oglala Lakota County, SD, Pennington County, SD, Perkins County, SD, Ziebach County, SD, Crook County, WY, Weston County, WY

The radar

The Rapid City radar (KUDX), 27 km from the middle of the area, began a volume at 20:59 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

Rapid City, SD (KUNR), launched 12:00Z, 8.9 hours before the alert went out and 33 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, Rapid City, SD at 12:00Z on 2012-03-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Rapid City, SD at 12:00Z on 2012-03-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 89 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1879 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
89 m²/s²
0-3 km storm-relative helicity
122 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.

363 
ACUS11 KWNS 262056
SWOMCD
SPC MCD 262056 
SDZ000-NEZ000-NDZ000-MTZ000-WYZ000-262300-

MESOSCALE DISCUSSION 0363
NWS STORM PREDICTION CENTER NORMAN OK
0356 PM CDT MON MAR 26 2012

AREAS AFFECTED...FAR SOUTHEAST MT/EASTERN WY TO WESTERN SD/SOUTHWEST
ND/WESTERN NEB

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 262056Z - 262300Z

AT LEAST AN ISOLATED SEVERE THREAT IS EXPECTED TO DEVELOP/INCREASE
THROUGH EARLY EVENING ACROSS THE NORTHERN HIGH PLAINS...INITIALLY
INCLUDING FAR SOUTHEAST MT/FAR EASTERN WY...AND ESPECIALLY INTO
WESTERN SD AND ADJACENT PARTS OF WESTERN NEB/SOUTHWEST ND. AT LEAST
PORTIONS OF THIS REGION MAY NEED A WATCH.

A CONSIDERABLE/COMPACT SHORTWAVE TROUGH AND ASSOCIATED SPEED MAX
CONTINUES TO QUICKLY SPREAD NORTHEASTWARD OVER WY PER SATELLITE
IMAGERY...WITH A COLD FRONT ALSO STEADILY PROGRESSING
EAST-NORTHEASTWARD ACROSS WY/NORTHWEST CO PER SURFACE
DATA/SATELLITE. AS THE HIGH PLAINS REGION INCREASINGLY COMES UNDER
THE INFLUENCE OF APPRECIABLE FORCING FOR ASCENT TOWARD
EVENING...TSTMS SHOULD STEADILY INCREASE WITHIN A MODESTLY
MOIST/RELATIVELY WELL-MIXED BOUNDARY LAYER. WHILE IT SEEMS PROBABLE
THAT A STOUT ELEVATED MIXED LAYER /PER REGIONAL 12Z OBSERVED
SOUNDINGS/ WILL SERVE TO CAP MUCH OF THE MODESTLY MOIST WARM SECTOR
AHEAD OF THE FRONT...A DEEP CONVECTIVE UPSWING IS EXPECTED TO BE
FOCUSED ALONG THE EAST-NORTHEAST ADVANCING COLD FRONT AS IT
OVERTAKES A HIGH PLAINS LEE TROUGH. IN SPITE OF LIMITED
MOISTURE/AGGRESSIVE MIXING OVER THE NEXT FEW HOURS...A STEEP LAPSE
ENVIRONMENT/INCREASINGLY STRONG VERTICAL SHEAR PROFILES AND AMPLE
FORCING ATTENDANT TO THE COLD FRONT SHOULD SUPPORT
SUSTAINED/ORGANIZED STORMS...SOME OF WHICH WILL BE STRONG/SEVERE.
WHILE HIGH-BASED/CONVECTIVELY ENHANCED WIND GUSTS WILL INITIALLY BE
POSSIBLE NEAR THE COLD FRONT...MUCH OF THE AVAILABLE HIGH-RES
CONVECTION-ALLOWING GUIDANCE SUGGEST THAT A POTENTIALLY MORE
ORGANIZED/SUSTAINED THREAT WILL BE FOCUSED ACROSS THE WESTERN HALF
OF SD DURING THE 23Z-03Z TIME FRAME. OVERALL...DAMAGING WINDS/SEVERE
HAIL WILL BE THE PRIMARY CONCERNS.

..GUYER.. 03/26/2012

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

ATTN...WFO...ABR...BIS...LBF...UNR...CYS...BYZ...

LAT...LON   44300100 42980135 42530224 42680400 44010475 45800483
            46480392 46250252 44300100

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 26, 5:28 PM MDTSevere Thunderstorm WatchSPCAdams, Bowman, Burleigh, Emmons, Grant, Hettinger and 8 more7 hr

Nearby

Mesoscale Discussions in South Dakota, 2012Mesoscale Discussions in North Dakota, 2012Mesoscale Discussions in Wyoming, 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.