Alert archive / Minnesota / Mesoscale Discussions in 2012
Mesoscale Discussion 1675
The Storm Prediction Center issued this mesoscale discussion at Aug 1, 2012, 4:14 PM CDT for 30 counties in Minnesota; Grant County, South Dakota; Pierce County, Polk County, Saint Croix County, Wisconsin. It was in force for 91 min.
The area
The outline as issued.
The facts
- Issued
- Aug 1, 2012, 4:14 PM CDT (21:14 UTC)
- Expired
- Aug 1, 2012, 5:45 PM CDT
- In force
- 91 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 60%
All 34 counties
Anoka County, MN, Benton County, MN, Brown County, MN, Carver County, MN, Chippewa County, MN, Chisago County, MN, Dakota County, MN, Goodhue County, MN, Hennepin County, MN, Isanti County, MN, Kandiyohi County, MN, Lac qui Parle County, MN, Le Sueur County, MN, Lyon County, MN, McLeod County, MN, Meeker County, MN, Nicollet County, MN, Ramsey County, MN, Redwood County, MN, Renville County, MN, Rice County, MN, Scott County, MN, Sherburne County, MN, Sibley County, MN, Stearns County, MN, Swift County, MN, Wabasha County, MN, Washington County, MN, Wright County, MN, Yellow Medicine County, MN, Grant County, SD, Pierce County, WI, Polk County, WI, Saint Croix County, WI
The radar
The Minneapolis radar (KMPX), 105 km from the middle of the area, began a volume at 21:16 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
Minneapolis, MN (KMPX), launched 12:00Z, 9.2 hours before the alert went out and 103 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
- 670 J/kg
- Mixed-layer CIN
- -340 J/kg
- Mixed-layer LCL
- 1367 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 246 m²/s²
- 0-3 km storm-relative helicity
- 292 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.1
The text
As transmitted, in the capitals the NWS used until 2016.
132
ACUS11 KWNS 012114
SWOMCD
SPC MCD 012114
WIZ000-MNZ000-SDZ000-012245-
MESOSCALE DISCUSSION 1675
NWS STORM PREDICTION CENTER NORMAN OK
0414 PM CDT WED AUG 01 2012
AREAS AFFECTED...PARTS OF CENTRAL/SRN MN AND FAR WEST CENTRAL WI
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 012114Z - 012245Z
PROBABILITY OF WATCH ISSUANCE...60 PERCENT
SUMMARY...THIS REGION WILL BE MONITORED FOR WW ISSUANCE BY 23-00Z.
TSTM DEVELOPMENT IS EXPECTED BETWEEN 21-00Z ACROSS CENTRAL INTO SRN
MN...WITH A SUBSEQUENT LIKELIHOOD FOR STORMS TO BECOME SEVERE GIVEN
THE DEGREE OF AVAILABLE INSTABILITY /MLCAPE OF 2500-3500 J PER KG/.
LARGE HAIL...SOME VERY LARGE...AND DAMAGING WINDS WILL BE THE
PRIMARY THREATS ONCE STORMS DEVELOP LATE THIS AFTERNOON AND EARLY
EVENING.
DISCUSSION...STRONG SURFACE HEATING AHEAD OF A COLD FRONT NOW MOVING
INTO CENTRAL MN HAS CONTRIBUTED TO VERY STRONG INSTABILITY WITH
MLCAPE RANGING FROM 2500-3500 J/KG EXTENDING WWD FROM WEST CENTRAL
WI. CONVECTIVE DEVELOPMENT IS AT A MINIMUM AT THE PRESENT TIME
ACROSS THE DISCUSSION AS THIS AREA RESIDES BETWEEN TWO SHORTWAVE
TROUGHS. HOWEVER...FORCING FOR ASCENT ATTENDANT TO THE PROGRESSIVE
DAKOTAS SYSTEM IS LIKELY SUPPORTING CONVECTIVE DEEPER CU FORMATION
ALONG THE COLD FRONT IN NERN SD /CLARK COUNTY/ WITH ADDITIONAL CU
AND ACCAS FORMATION EWD INTO CENTRAL MN.
12Z NAM/12Z NSSL-4 KM WRF AND THE 16/17Z RUNS OF THE HRRR ALL
SUGGEST AT LEAST ISOLATED TSTM DEVELOPMENT INTO CENTRAL MN BY 00Z
WITH ACTIVITY MOVING SSEWD. ALTHOUGH EFFECTIVE BULK SHEAR IS
CURRENTLY WEAK...AN INCREASE IN VALUES DURING THE NEXT SEVERAL HOURS
AND THE DEGREE OF INSTABILITY ARE EXPECTED TO SUPPORT SEVERE STORMS
WITH HAIL AND DAMAGING WINDS THE PRIMARY THREATS.
..PETERS/HART.. 08/01/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...DLH...ARX...MPX...FSD...ABR...
LAT...LON 45279694 45579564 45839299 45629231 44079209 44129421
44449637 44519656 45279694SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 1, 1:07 PM CDT | Mesoscale Discussion | SPC | Anoka, Carver, Chisago, Dakota, Goodhue, Hennepin and 6 more | 23 min |
| Aug 1, 5:12 PM CDT | Severe Thunderstorm Watch | SPC | Anoka, Blue Earth, Brown, Carver, Chippewa, Cottonwood and 28 more | 5 hr |
| Aug 1, 2:53 PM CDT | Mesoscale Discussion | SPC | Aurora, Beadle, Bennett, Brule, Buffalo, Charles Mix and 20 more | 67 min |
| Aug 1, 3:19 PM CDT | Severe Thunderstorm Watch | SPC | Aurora, Beadle, Bennett, Brule, Buffalo, Charles Mix and 28 more | 6 hr |
| Aug 1, 2:19 PM CDT | Severe Thunderstorm Watch | SPC | Clark, Forest, Langlade, Lincoln, Marathon, Marinette and 7 more | 4 hr |
Nearby
Mesoscale Discussions in Minnesota, 2012Mesoscale Discussions in Wisconsin, 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.