Alert archive / South Dakota / Mesoscale Discussions in 2006

Mesoscale Discussion 511

April 15, 200621 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Apr 15, 2006, 1:14 PM CDT for 21 counties in South Dakota. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued: Apr 15, 2006, 1:14 PM CDT (18:14 UTC)
Expired: Apr 15, 2006, 2:45 PM CDT
In force: 91 min
Issued by: the Storm Prediction Center

All 21 counties

Aurora County, SD, Beadle County, SD, Brule County, SD, Buffalo County, SD, Davison County, SD, Douglas County, SD, Haakon County, SD, Hand County, SD, Hanson County, SD, Hughes County, SD, Hyde County, SD, Jackson County, SD, Jerauld County, SD, Jones County, SD, Lyman County, SD, Mellette County, SD, Sanborn County, SD, Stanley County, SD, Sully County, SD, Todd County, SD, Tripp County, SD

The radar

The Rapid City radar (KUDX), 181 km from the middle of the area, began a volume at 18:14 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

Rapid City, SD (KUNR), launched 12:00Z, 6.2 hours before the alert went out and 183 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 3140 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: -10 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.

000 
ACUS11 KWNS 151815
SWOMCD
SPC MCD 151814 
SDZ000-151945-

MESOSCALE DISCUSSION 0511
NWS STORM PREDICTION CENTER NORMAN OK
0114 PM CDT SAT APR 15 2006

AREAS AFFECTED...SOUTHERN SD

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 151814Z - 151945Z

THREAT FOR ISOLATED LARGE HAIL MAY INCREASE THROUGH EARLY/MID
AFTERNOON ACROSS SOUTHERN SD. GIVEN EXPECTED MARGINAL/ISOLATED
NATURE...A SEVERE WATCH IS NOT CURRENTLY ANTICIPATED...BUT
CONVECTIVE TRENDS WILL BE MONITORED. 

ARC OF TSTMS HAS RECENTLY INCREASED IN INTENSITY ACROSS SOUTHERN
SD...LIKELY TIED TO INCREASING ELEVATED INSTABILITY VIA
DRYSLOT/FORCING FOR ASCENT ASSOCIATED WITH CENTRAL HIGH PLAINS
CYCLONE. 17Z RUC/09Z NAMKF SOUNDINGS SUGGEST MUCAPE WILL GENERALLY
REMAIN AT 300-500 J/KG OR LESS ACROSS MUCH OF SOUTHERN SD. GIVEN THE
ELEVATED NATURE OF BUOYANCY...LARGE HAIL WOULD BE THE PRIMARY
HAZARD. CURRENT EXPECTATIONS ARE THAT THE THREAT WILL REMAIN
SUFFICIENTLY MARGINAL/ISOLATED GIVEN MODEST INSTABILITY/CLOUD
BEARING SHEARING SUCH THAT A WATCH MAY NOT BE NEEDED...HOWEVER WILL
CONTINUE TO MONITOR.

..GUYER.. 04/15/2006

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

ATTN...WFO...FSD...ABR...UNR...

43230242 44080258 44760155 44709833 43429766 43169945
43150077

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 15, 6:41 PM CDT	Mesoscale Discussion	SPC	Clay, Lincoln, Turner, Union	94 min

Nearby

Mesoscale Discussions in South Dakota, 2006 Every mesoscale discussion in 2006

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.