Alert archive / Minnesota / Mesoscale Discussions in 2012

Mesoscale Discussion 1648

July 29, 20125 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at Jul 29, 2012, 7:37 PM CDT for 5 counties in Minnesota. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
Jul 29, 2012, 7:37 PM CDT (00:37 UTC)
Expired
Jul 29, 2012, 8:30 PM CDT
In force
53 min
Issued by
the Storm Prediction Center
Chance of a watch
80%

Counties Kittson County, MN, Koochiching County, MN, Lake of the Woods County, MN, Marshall County, MN, Roseau County, MN

The radar

The Fargo/Grand Forks radar (KMVX), 184 km from the middle of the area, began a volume at 00:41 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

International Fa, MN (KINL), launched 00:00Z, 0.6 hours before the alert went out and 145 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, International Fa, MN at 00:00Z on 2012-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1490 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, International Fa, MN at 00:00Z on 2012-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 71 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
1490 J/kg
Mixed-layer CIN
-31 J/kg
Mixed-layer LCL
1732 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
71 m²/s²
0-3 km storm-relative helicity
119 m²/s²
Significant tornado parameter
0.2
Supercell composite
4.9

Open this sounding in Storm Lab

The text

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

976 
ACUS11 KWNS 300037
SWOMCD
SPC MCD 300037 
MNZ000-300130-

MESOSCALE DISCUSSION 1648
NWS STORM PREDICTION CENTER NORMAN OK
0737 PM CDT SUN JUL 29 2012

AREAS AFFECTED...EXTREME NERN ND INTO NRN MN

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

VALID 300037Z - 300130Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...STORMS ARE EXPECTED TO DEVELOP SEWD INTO NRN MN THIS
EVENING. THE STRONGER STORMS MAY POSE A THREAT FOR ISOLATED DAMAGING
WIND AND LARGE HAIL. WW WILL LIKELY BE NEEDED SOON.

DISCUSSION...STORMS ARE DEVELOPING ALONG SEWD MOVING OUTFLOW
BOUNDARY NEAR THE BORDER OF MANITOBA...NERN ND AND NWRN MN. OTHER
STORMS HAVE FORMED ALONG NERN EXTENSION OF COLD FRONT IN NERN ND.
THE COMBINATION OF MESOSCALE ASCENT ALONG THE PROGRESSIVE OUTFLOW
BOUNDARY AUGMENTED BY A STRENGTHENING SWLY LLJ ASSOCIATED WITH SEWD
MOVING SHORTWAVE TROUGH WILL LIKELY PROMOTE THUNDERSTORM DEVELOPMENT
INTO NRN MN THIS EVENING DESPITE INCREASING CONVECTIVE INHIBITION.
ATMOSPHERE IN THIS REGION IS MODERATELY UNSTABLE WITH 1500-2000 J/KG
MLCAPE AND EFFECTIVE SHEAR WILL INCREASE TO 35-40 KT IN ASSOCIATION
WITH APPROACHING MID LEVEL JET.

..DIAL/MEAD.. 07/30/2012

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

ATTN...WFO...DLH...FGF...

LAT...LON   48919708 48859512 48379331 47949326 47889426 48289673
            48919708

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 29, 7:51 PM CDTSevere Thunderstorm WatchSPCBeltrami, Itasca, Kittson, Koochiching, Lake, Lake of the Woods and 3 more6 hr
Jul 29, 11:03 PM CDTMesoscale DiscussionSPCBeltrami, Itasca, Koochiching, Lake, Saint Louis117 min

Nearby

Mesoscale 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.