Alert archive / South Dakota / Mesoscale Discussions in 2013
Mesoscale Discussion 1621
The Storm Prediction Center issued this mesoscale discussion at Aug 5, 2013, 2:04 AM MDT for 16 counties in South Dakota. It was in force for 56 min.
The area
The outline as issued.
The facts
- Issued
- Aug 5, 2013, 2:04 AM MDT (08:04 UTC)
- Expired
- Aug 5, 2013, 3:00 AM MDT
- In force
- 56 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 60%
Counties Bennett County, SD, Brule County, SD, Buffalo County, SD, Custer County, SD, Fall River County, SD, Haakon County, SD, Hughes County, SD, Jackson County, SD, Jones County, SD, Lyman County, SD, Mellette County, SD, Oglala Lakota County, SD, Pennington County, SD, Stanley County, SD, Todd County, SD, Tripp County, SD
The radar
The Rapid City radar (KUDX), 117 km from the middle of the area, began a volume at 08:07 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 (KRAP), launched 00:00Z, 8.1 hours before the alert went out and 118 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.
- Mixed-layer CAPE
- 352 J/kg
- Mixed-layer CIN
- -170 J/kg
- Mixed-layer LCL
- 2206 m above ground
- 0-6 km bulk shear
- 49 kt
- 0-1 km storm-relative helicity
- -73 m²/s²
- 0-3 km storm-relative helicity
- 76 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.0
The text
As transmitted, in the capitals the NWS used until 2016.
469
ACUS11 KWNS 050805
SWOMCD
SPC MCD 050804
SDZ000-NEZ000-WYZ000-050900-
MESOSCALE DISCUSSION 1621
NWS STORM PREDICTION CENTER NORMAN OK
0304 AM CDT MON AUG 05 2013
AREAS AFFECTED...SRN SD...FAR ERN WY
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 050804Z - 050900Z
PROBABILITY OF WATCH ISSUANCE...60 PERCENT
SUMMARY...AN ISOLATED SEVERE THREAT MAY CONTINUE ACROSS SRN SD OVER
THE NEXT FEW HOURS. LARGE HAIL AND WIND DAMAGE WILL BE THE PRIMARY
THREATS. WW ISSUANCE MAY BE NEEDED ACROSS THE REGION EARLY THIS
MORNING.
DISCUSSION...STRONG TO SEVERE THUNDERSTORMS ARE ONGOING FROM NEAR
NEWCASTLE WY EXTENDING EWD TO THE BADLANDS OF SD. THIS ACTIVITY IS
LOCATED ALONG A CORRIDOR OF INSTABILITY WHERE MESOANALYSIS IS
ESTIMATING MLCAPE IN THE 500 TO 1500 J/KG RANGE. IN ADDITION...THE
WSR-88D VWP AT RAPID CITY SHOW ABOUT 40 KT OF 0-6 KM SHEAR. DEEP
LAYER SHEAR IS PROBABLY A BIT STRONGER ACROSS SCNTRL SD WHERE THE
EDGE OF A MID-LEVEL JET IS LOCATED. THIS ENVIRONMENT COMBINED WITH
MID-LEVEL LAPSE RATES APPROACHING 8.0 C/KM SHOULD BE FAVORABLE FOR
LARGE HAIL. WIND DAMAGE WILL ALSO BE POSSIBLE ESPECIALLY CONSIDERING
STORM MOTIONS ARE ELY AT ABOUT 40 KT.
..BROYLES/CORFIDI.. 08/05/2013
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...FSD...ABR...LBF...UNR...CYS...
LAT...LON 43489899 44129900 44489959 44470067 44260224 44090370
43940415 43550430 43290419 43090385 42980260 42850132
42860033 43029951 43489899SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 5, 2:14 AM MDT | Severe Thunderstorm Watch | SPC | Bennett, Custer, Fall River, Haakon, Jackson, Jones and 5 more | 3 hr |
| Aug 5, 5:14 AM MDT | Mesoscale Discussion | SPC | Aurora, Bennett, Bon Homme, Brule, Charles Mix, Douglas and 7 more | 91 min |
| Aug 5, 2:31 PM MDT | Mesoscale Discussion | SPC | Butte, Custer, Fall River, Lawrence, Pennington | 89 min |
Nearby
Mesoscale Discussions in South Dakota, 2013Every mesoscale discussion in 2013
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.