Alert archive / South Dakota / Mesoscale Discussions in 2006

Mesoscale Discussion 1521

July 15, 200613 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 15, 2006, 3:08 PM CDT for 13 counties in South Dakota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jul 15, 2006, 3:08 PM CDT (20:08 UTC)
Expired: Jul 15, 2006, 5:15 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Buffalo County, SD, Faulk County, SD, Hand County, SD, Hughes County, SD, Hyde County, SD, Jones County, SD, Lyman County, SD, Mellette County, SD, Potter County, SD, Stanley County, SD, Sully County, SD, Todd County, SD, Tripp County, SD

The radar

The Aberdeen radar (KABR), 182 km from the middle of the area, began a volume at 20:08 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

Aberdeen, SD (KABR), launched 12:00Z, 8.1 hours before the alert went out and 142 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: 399 J/kg
Mixed-layer CIN: -647 J/kg
Mixed-layer LCL: 2283 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 246 m²/s²
0-3 km storm-relative helicity: 343 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 152008
SWOMCD
SPC MCD 152008 
SDZ000-152215-

MESOSCALE DISCUSSION 1521
NWS STORM PREDICTION CENTER NORMAN OK
0308 PM CDT SAT JUL 15 2006

AREAS AFFECTED...CENTRAL AND NERN SD

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 152008Z - 152215Z

ISOLATED SVR TSTM OR TWO MAY DEVELOP NEAR A SFC LOW AND ALONG A LEE
TROUGH FROM SCENTRAL SD NEWD INTO NCENTRAL/NERN SD OVER THE NEXT
SEVERAL HRS. PORTIONS OF NERN SD MAY NEED A WW LATER THIS AFTERNOON.


LATEST VIS SAT IMAGERY SHOWED CONGESTED HIGH BASED CONVECTION
DEVELOPING ALONG A LEE TROUGH OVER SCENTRAL SD AND FAR NWRN NEB.
VERY HOT TEMPERATURES WITH READINGS IN THE 110-115 F RANGE HAVE LED
TO VERY LITTLE CINH AND THUS CONVECTION IS ANTICIPATED TO INCREASE
IN INTENSITY OVER THE NEXT FEW HRS WHILE DEVELOPING INTO CENTRAL SD.
GREATER CINH EXISTS ATTM OVER NERN SD...BUT SEVERAL MORE HRS OF
HEATING SHOULD SUPPORT ISOLATED TSTM DEVELOPMENT NEAR A SFC LOW OVER
NCENTRAL SD. INVERTED-V PROFILES WITH 50-60 DEG T/TD SPREADS
COMBINED WITH MODEST INSTABILITY /MLCAPES FROM 1000-1500 J/KG/
SHOULD SUPPORT SOME DMGG WIND POTENTIAL WITH THE STRONGEST TSTMS.
MODERATE LOW LEVEL FLOW AND STRONGER EFFECTIVE VERTICAL SHEAR OVER
NERN SD MAY SUPPORT A MORE ORGANIZED SVR THREAT AND NEED FOR A WW.
HOWEVER...GREATER CINH EXIST OVER THIS AREA...AND THUS SEVERAL MORE
HRS OF HEATING AND CONVERGENCE WILL BE NEEDED.

..CROSBIE.. 07/15/2006

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

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

45469905 45010020 44330084 43570124 43290116 43190097
43160032 43189965 43719918 44619849 45279840

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.