Alert archive / Wisconsin / Mesoscale Discussions in 2012

Mesoscale Discussion 1680

August 1, 20125 counties in Minnesota; 9 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Aug 1, 2012, 10:11 PM CDT for 5 counties in Minnesota; 9 counties in Wisconsin. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued
Aug 1, 2012, 10:11 PM CDT (03:11 UTC)
Expired
Aug 1, 2012, 11:45 PM CDT
In force
94 min
Issued by
the Storm Prediction Center
Chance of a watch
40%

Counties Fillmore County, MN, Houston County, MN, Olmsted County, MN, Wabasha County, MN, Winona County, MN, Buffalo County, WI, Jackson County, WI, Juneau County, WI, La Crosse County, WI, Monroe County, WI, Pepin County, WI, Pierce County, WI, Trempealeau County, WI, Vernon County, WI

The radar

The La Crosse radar (KARX), 63 km from the middle of the area, began a volume at 03:14 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

Minneapolis, MN (KMPX), launched 00:00Z, 3.2 hours before the alert went out and 160 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-pSkew-T log-p diagram, Minneapolis, MN at 00:00Z on 2012-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2247 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 00:00Z on 2012-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 51 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
2247 J/kg
Mixed-layer CIN
-65 J/kg
Mixed-layer LCL
1724 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
51 m²/s²
0-3 km storm-relative helicity
101 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.9

Open this sounding in Storm Lab

The text

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

837 
ACUS11 KWNS 020312
SWOMCD
SPC MCD 020311
WIZ000-IAZ000-MNZ000-020445-

MESOSCALE DISCUSSION 1680
NWS STORM PREDICTION CENTER NORMAN OK
1011 PM CDT WED AUG 01 2012

AREAS AFFECTED...EXTREME SERN MN/SWRN WI

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 020311Z - 020445Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...A SMALL CLUSTER OF SVR TSTMS OVER SERN MN MAY CONTINUE TO
POSE A SVR WIND/HAIL THREAT FOR A FEW MORE HOURS AS IT MOVES EWD
INTO SWRN WI. CONVECTIVE TRENDS ARE BEING MONITORED.

DISCUSSION...A SMALL CLUSTER OF SVR TSTMS OVER SERN MN WILL MOVE
GENLY EWD INTO SWRN WI THROUGH 05Z. THE ENVIRONMENT IN THE IMMEDIATE
PATH OF THIS CLUSTER IS FAVORABLE FOR A CONTINUED LOCALIZED SVR WIND
AND HAIL THREAT. LATEST OBJECTIVE ANALYSIS SUGGESTS TSTM CLUSTER IS
CURRENTLY MOVING THROUGH AN AXIS OF MODERATE TO STRONG INSTABILITY
WITH MUCAPE 2000 TO 3000 J/KG AND EFFECTIVE BULK SHEAR OF 25 TO 30
KT. ALTHOUGH THE SVR THREAT IS CURRENTLY RELATIVELY
LOCALIZED...CONVECTIVE TRENDS WILL BE MONITORED FOR SIGNS OF A
DEVELOPING COLD POOL WHICH WOULD SUGGEST A MORE SUSTAINED SVR
THREAT.

..BUNTING/HART.. 08/02/2012

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

ATTN...WFO...MKX...ARX...MPX...

LAT...LON   43749259 44299269 44599269 44809259 44839240 44849224
            44709155 44259042 43788993 43409034 43409107 43669227
            43759260 43749259

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 1, 7:35 PM CDTMesoscale DiscussionSPCAnoka, Blue Earth, Brown, Carver, Chippewa, Cottonwood and 27 more55 min

Nearby

Mesoscale Discussions in Wisconsin, 2012Mesoscale Discussions in Minnesota, 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.