Alert archive / Minnesota / Mesoscale Discussions in 2011

Mesoscale Discussion 1813

August 1, 201111 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at Aug 1, 2011, 10:42 AM CDT for 11 counties in Minnesota. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued
Aug 1, 2011, 10:42 AM CDT (15:42 UTC)
Expired
Aug 1, 2011, 11:45 AM CDT
In force
63 min
Issued by
the Storm Prediction Center

Counties Benton County, MN, Kandiyohi County, MN, Meeker County, MN, Mille Lacs County, MN, Morrison County, MN, Pope County, MN, Sherburne County, MN, Stearns County, MN, Swift County, MN, Todd County, MN, Wright County, MN

The radar

The Minneapolis radar (KMPX), 92 km from the middle of the area, began a volume at 15:43 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, 3.7 hours before the alert went out and 90 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 12:00Z on 2011-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2974 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 12:00Z on 2011-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 square meters per square second.193958Sfc1 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
2974 J/kg
Mixed-layer CIN
-122 J/kg
Mixed-layer LCL
898 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
10 m²/s²
0-3 km storm-relative helicity
59 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

628 
ACUS11 KWNS 011543
SWOMCD
SPC MCD 011542
MNZ000-011645-

MESOSCALE DISCUSSION 1813
NWS STORM PREDICTION CENTER NORMAN OK
1042 AM CDT MON AUG 01 2011

AREAS AFFECTED...CENTRAL MN

CONCERNING...SEVERE THUNDERSTORM WATCH 708...

VALID 011542Z - 011645Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 708
CONTINUES.

ISOLATED STRONG TO SEVERE STORMS REMAIN POSSIBLE MAINLY ACROSS
CENTRAL MN THROUGH 17Z.  OVERALL DECREASING TREND IN COVERAGE OF
STRONGER ACTIVITY IS EXPECTED TO CONTINUE THROUGH EARLY AFTERNOON
AND THUS WILL LIMIT THE NEED FOR A NEW WW.

SURFACE ANALYSES INDICATED A CONVECTIVE OUTFLOW BOUNDARY EXTENDED
FROM THE TWIN CITIES METRO WSWWD TO JUST N OF RWF...NEAR ATY...TO 35
SE MBG.  25-30 KT SWLY LLJ EXTENDING INTO ERN SD/WEST CENTRAL MN WAS
MAINTAINING A WAA REGIME ALONG AND N OF THE OUTFLOW BOUNDARY AND
SUPPORTING ADDITIONAL TSTM DEVELOPMENT WITHIN THE REMNANT MCS.
INFLOW OF STEEPER MIDLEVEL LAPSE RATES AND STRONGER INSTABILITY
RESIDING OVER SD COMBINED WITH EFFECTIVE BULK SHEAR /40-50 KT/
ACROSS CENTRAL MN SUGGEST THIS TSTM COMPLEX WILL CONTINUE TO HAVE
NEW DEVELOPMENT INTO THE AFTERNOON.  HOWEVER...GIVEN DOWNSTREAM
CLOUD AND PRECIPITATION SHIELD LIMITING SURFACE HEATING AND
REDUCTION OF SBCINH...TSTM ACTIVITY IS EXPECTED TO REMAIN ELEVATED
WITH PERIODIC STRONGER UPDRAFTS SUPPORTING AN ISOLATED SEVERE STORM.

..PETERS.. 08/01/2011

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

ATTN...WFO...DLH...MPX...

LAT...LON   44969385 44969470 45249570 45869559 46109512 46169417
            45969347 45449327 45199346 44969385

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 31, 10:26 PM CDTSevere Thunderstorm WatchSPCBecker, Clay, Clearwater, Grant, Kittson, Mahnomen and 8 more8 hr
Aug 1, 12:35 AM CDTMesoscale DiscussionSPCClay, Norman, Polk85 min
Aug 1, 2:31 AM CDTMesoscale DiscussionSPCBecker, Cass, Clay, Clearwater, Crow Wing, Douglas and 11 more89 min
Aug 1, 4:57 AM CDTSevere Thunderstorm WatchSPCBecker, Benton, Big Stone, Brown, Cass, Chippewa and 28 more7 hr
Aug 1, 7:31 AM CDTMesoscale DiscussionSPCAnoka, Benton, Blue Earth, Brown, Carver, Chippewa and 33 more89 min
Aug 1, 11:29 AM CDTMesoscale DiscussionSPCAnoka, Benton, Carver, Chisago, Dakota, Hennepin and 8 more31 min
Aug 1, 11:52 AM CDTSevere Thunderstorm WatchSPCAnoka, Becker, Benton, Big Stone, Blue Earth, Brown and 43 more7 hr
Aug 1, 1:50 PM CDTMesoscale DiscussionSPCBlue Earth, Dakota, Dodge, Fillmore, Freeborn, Goodhue and 12 more25 min
Aug 1, 2:04 PM CDTSevere Thunderstorm WatchSPCDodge, Fillmore, Houston, Mower, Olmsted, Wabasha and 1 more5 hr
Aug 1, 3:53 PM CDTMesoscale DiscussionSPCAnoka, Becker, Benton, Blue Earth, Carver, Chippewa and 47 more67 min

Nearby

Mesoscale Discussions in Minnesota, 2011Every mesoscale discussion in 2011

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.