Alert archive / North Dakota / Mesoscale Discussions in 2012
Mesoscale Discussion 1833
The Storm Prediction Center issued this mesoscale discussion at Aug 29, 2012, 1:53 PM MDT for 8 counties in North Dakota; 6 counties in South Dakota. It was in force for 97 min.
The area
The outline as issued.
The facts
- Issued
- Aug 29, 2012, 1:53 PM MDT (19:53 UTC)
- Expired
- Aug 29, 2012, 3:30 PM MDT
- In force
- 97 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
Counties Adams County, ND, Grant County, ND, Hettinger County, ND, Mercer County, ND, Morton County, ND, Oliver County, ND, Sioux County, ND, Stark County, ND, Corson County, SD, Dewey County, SD, Haakon County, SD, Perkins County, SD, Stanley County, SD, Ziebach County, SD
The radar
The Bismarck radar (KBIS), 135 km from the middle of the area, began a volume at 19:53 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
Bismarck Municip, ND (KBIS), launched 12:00Z, 7.9 hours before the alert went out and 138 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
- 784 J/kg
- Mixed-layer CIN
- -477 J/kg
- Mixed-layer LCL
- 1518 m above ground
- 0-6 km bulk shear
- 6 kt
- 0-1 km storm-relative helicity
- -77 m²/s²
- 0-3 km storm-relative helicity
- -31 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted, in the capitals the NWS used until 2016.
239
ACUS11 KWNS 291953
SWOMCD
SPC MCD 291953
SDZ000-NDZ000-292130-
MESOSCALE DISCUSSION 1833
NWS STORM PREDICTION CENTER NORMAN OK
0253 PM CDT WED AUG 29 2012
AREAS AFFECTED...PORTIONS OF WRN/CNTRL SD...SWRN/S-CNTRL ND
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 291953Z - 292130Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...ISOLATED THUNDERSTORMS ARE FORECAST TO MOVE ACROSS
PORTIONS OF WRN/CNTRL SD AND SWRN/S-CNTRL ND THIS AFTERNOON AND
EVENING. A STORM OR TWO MAY BECOME CAPABLE OF PRODUCING DAMAGING
WIND GUSTS AND LARGE HAIL...BUT THE SVR WEATHER THREAT IS EXPECTED
TO BE TOO MARGINAL FOR A WW.
DISCUSSION...SUBJECTIVE SURFACE ANALYSIS AT 19Z SHOWED A COLD FRONT
ARCING S-SWWD-WWD ACROSS WRN ND INTO SRN MT...WHILE A WARM FRONT
EXTENDED S-SEWD ACROSS CNTRL SD INTO NWRN IA. THE AIRMASS S OF THE
COLD FRONT AND W OF THE WARM FRONT IS VERY HOT AND WELL
MIXED...WHILE CONDITIONS N AND E OF THE COLD FRONT/WARM FRONT ARE
SLIGHTLY COOLER AND MORE MOIST WITH DEWPOINTS IN THE 50S TO MID 60S.
VISIBLE SATELLITE IMAGERY INDICATES CUMULUS ARE DEEPENING INVOF THE
BLACK HILLS...WITH ONE CELL PRODUCING A COUPLE OF LIGHTNING STRIKES.
AS THIS CUMULUS SPREADS E-NEWD TOWARD THE WARM FRONT...ADDITIONAL
ISOLATED THUNDERSTORM DEVELOPMENT WILL BE POSSIBLE AS SLIGHTLY
GREATER MOISTURE AND CAPE IS ENCOUNTERED. IN ADDITION...OTHER STORMS
MAY FORM ALONG THE COLD FRONT AS THE BOUNDARY MOVES E TOWARD CNTRL
ND. THOUGH STRONGEST DEEP-LAYER SHEAR WILL GENERALLY BE CONFINED
FARTHER N NEAR THE CANADIAN BORDER...STEEP LOW AND MIDLEVEL LAPSE
RATES WILL PROMOTE THE DEVELOPMENT OF ISOLATED STRONG/SVR MULTICELL
THUNDERSTORMS OVER THE DISCUSSION AREA.
..GARNER/WEISS.. 08/29/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...ABR...BIS...UNR...
LAT...LON 47030282 47370171 46690061 44510047 43930148 44260257
46170312 47030282Nearby
Mesoscale Discussions in North Dakota, 2012Mesoscale Discussions in South Dakota, 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.