Alert archive / Minnesota / Mesoscale Discussions in 2012

Mesoscale Discussion 2021

October 4, 201213 counties in Minnesota; Grand Forks County, Traill County, North Dakota

The Storm Prediction Center issued this mesoscale discussion at Oct 4, 2012, 5:50 AM CDT for 13 counties in Minnesota; Grand Forks County, Traill County, North Dakota. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Oct 4, 2012, 5:50 AM CDT (10:50 UTC)
Expired
Oct 4, 2012, 11:45 AM CDT
In force
6 hr
Issued by
the Storm Prediction Center

Counties Becker County, MN, Beltrami County, MN, Clay County, MN, Clearwater County, MN, Kittson County, MN, Lake of the Woods County, MN, Mahnomen County, MN, Marshall County, MN, Norman County, MN, Pennington County, MN, Polk County, MN, Red Lake County, MN, Roseau County, MN, Grand Forks County, ND, Traill County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 133 km from the middle of the area, began a volume at 10:53 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

International Fa, MN (KINL), launched 00:00Z, 10.8 hours before the alert went out and 208 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 2012-10-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, International Fa, MN at 00:00Z on 2012-10-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 61 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1602 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
61 m²/s²
0-3 km storm-relative helicity
311 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

893 
ACUS11 KWNS 041050
SWOMCD
SPC MCD 041050 
MNZ000-NDZ000-041645-

MESOSCALE DISCUSSION 2021
NWS STORM PREDICTION CENTER NORMAN OK
0550 AM CDT THU OCT 04 2012

AREAS AFFECTED...NERN ND...NWRN MN

CONCERNING...HEAVY SNOW 

VALID 041050Z - 041645Z

SUMMARY...A SMALL BUT INTENSE AREA OF PRECIPITATION WILL CHANGE TO
ALL SNOW THROUGH THE LATE MORNING HOURS...WITH HEAVIEST SNOWFALL
RATES ACROSS FAR NWRN MN THROUGH 18Z. RATES OF 1-2 IN/HR APPEAR
LIKELY.

DISCUSSION...A SURFACE LOW WILL CONTINUE TO GRADUALLY DEEPEN AS IT
MOVES NWD ACROSS NRN MN TODAY WITH ASSOCIATED COMMA HEAD PRECIP
SHIFTING EWD ACROSS THE RED RIVER AND INTO THE LAKE OF THE WOODS
AREA BY 18Z.

PERSISTENT UPWARD VERTICAL MOTION WITH THE DEEPENING LOW AND AMPLE
PRECIPITABLE WATER SHOULD ALLOW FOR A CHANGEOVER TO ALL SNOW ACROSS
MUCH OF NWRN MN OVER THE NEXT SEVERAL HOURS. FORECAST SOUNDINGS
INDICATE THE LIKELIHOOD OF HEAVY DENDRITIC GROWTH ALOFT...WHICH WILL
EVENTUALLY MAKE IT TO THE SURFACE AS COLD ADVECTION DROPS THE
850-700 MB LAYER BELOW FREEZING. MODEL QPF AND SREF WINTER ENSEMBLE
OUTPUT SUGGEST THAT HEAVY WET SNOWFALL RATES UP TO 2 IN/HR MAY OCCUR
OVER NWRN MN...ALTHOUGH ACTUAL SURFACE ACCUMULATION WILL LIKELY BE
LESS.

..JEWELL.. 10/04/2012

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

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

LAT...LON   47979758 48749750 49089717 49929615 50089527 50029480
            49369466 48159464 47129506 46859554 46819640 47129703
            47979758

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 3, 11:15 PM CDTMesoscale DiscussionSPCBecker, Clay, Clearwater, Kittson, Mahnomen, Marshall and 6 more5 hr

Nearby

Mesoscale Discussions in Minnesota, 2012Mesoscale Discussions in North 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.