Alert archive / South Dakota / Mesoscale Discussions in 2016

Mesoscale Discussion 1639

September 4, 2016Wilkin County, Minnesota; 6 counties in North Dakota; 30 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Sep 4, 2016, 9:16 PM CDT for Wilkin County, Minnesota; 6 counties in North Dakota; 30 counties in South Dakota. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued
Sep 4, 2016, 9:16 PM CDT (02:16 UTC)
Expired
Sep 4, 2016, 10:15 PM CDT
In force
59 min
Issued by
the Storm Prediction Center
All 37 counties

Wilkin County, MN, Dickey County, ND, LaMoure County, ND, McIntosh County, ND, Ransom County, ND, Richland County, ND, Sargent County, ND, Aurora County, SD, Beadle County, SD, Brown County, SD, Brule County, SD, Buffalo County, SD, Clark County, SD, Codington County, SD, Davison County, SD, Day County, SD, Douglas County, SD, Edmunds County, SD, Faulk County, SD, Hamlin County, SD, Hand County, SD, Hanson County, SD, Hughes County, SD, Hyde County, SD, Jerauld County, SD, Jones County, SD, Kingsbury County, SD, Lyman County, SD, Marshall County, SD, McPherson County, SD, Mellette County, SD, Miner County, SD, Potter County, SD, Roberts County, SD, Sanborn County, SD, Spink County, SD, Sully County, SD

The radar

The Aberdeen radar (KABR), 108 km from the middle of the area, began a volume at 02:20 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

Aberdeen, SD (KABR), launched 00:00Z, 2.3 hours before the alert went out and 66 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, Aberdeen, SD at 00:00Z on 2016-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 359 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, Aberdeen, SD at 00:00Z on 2016-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 113 square meters per square second.1939587897Sfc1 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
359 J/kg
Mixed-layer CIN
-176 J/kg
Mixed-layer LCL
1204 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
113 m²/s²
0-3 km storm-relative helicity
131 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.8

Open this sounding in Storm Lab

The text

As transmitted.

368 
ACUS11 KWNS 050216
SWOMCD
SPC MCD 050216 
MNZ000-SDZ000-NDZ000-050315-

MESOSCALE DISCUSSION 1639
NWS STORM PREDICTION CENTER NORMAN OK
0916 PM CDT SUN SEP 04 2016

AREAS AFFECTED...EASTERN SD...SERN ND

CONCERNING...SEVERE THUNDERSTORM WATCH 466...

VALID 050216Z - 050315Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 466
CONTINUES.

SUMMARY...SEVERE THREAT IS INCREASING ACROSS THE SOUTHERN HALF OF
WW466.

DISCUSSION...HIGH PLAINS CONVECTION THAT DEVELOPED OVER SWRN SD/NEB
PANHANDLE HAS MATURED INTO A WELL-DEFINED MCS OVER SCNTRL SD. 
LATEST RADAR DATA SUGGESTS AN MCV HAS FORMED SW OF PIR OVER JONES
COUNTY.  A BOWING SEGMENT IS SURGING NEWD IN EXCESS OF 40KT IN
ADVANCE OF THIS FEATURE AND IS LIKELY GENERATING DAMAGING WINDS
ALONG THE LEADING EDGE OF THE BOW...ESPECIALLY LYMAN COUNTY SD. 
THIS COMPLEX SHOULD SPREAD ACROSS MUCH OF THE SRN HALF OF WW466 OVER
THE NEXT FEW HOURS.

CONVECTION WILL CONTINUE TO DEVELOP NEAR THE FRONTAL ZONE EXTENDING
ACROSS NCNTRL SD INTO ERN ND.  HOWEVER...MUCH OF THIS ACTIVITY HAS
STRUGGLED TO ATTAIN SEVERE LEVELS.  FOR THIS REASON...MARGINALLY
SEVERE HAIL MAY BE THE GREATEST RISK WITH THIS ELEVATED OR NEAR-SFC
BASED CONVECTION.

..DARROW.. 09/05/2016

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

ATTN...WFO...FGF...FSD...ABR...BIS...UNR...

LAT...LON   43350115 46569941 46569606 43359795 43350115

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 5, 1:10 AM CDTMesoscale DiscussionSPCCottonwood, Murray, Nobles2 hr
Sep 5, 3:08 PM CDTMesoscale DiscussionSPCChippewa, Kandiyohi, Lac qui Parle, Lincoln, Lyon, McLeod and 8 more2 hr
Sep 4, 8:57 PM CDTMesoscale DiscussionSPCBennett, Jackson, Mellette, Todd93 min
Sep 4, 10:40 PM CDTSevere Thunderstorm WatchSPCAurora, Beadle, Bon Homme, Charles Mix, Clay, Davison and 14 more4 hr
Sep 5, 6:09 PM CDTMesoscale DiscussionSPCCuster, Fall River, Lawrence3 hr

Nearby

Mesoscale Discussions in South Dakota, 2016Mesoscale Discussions in North Dakota, 2016Mesoscale Discussions in Minnesota, 2016Every mesoscale discussion in 2016

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.