Alert archive / Minnesota / Mesoscale Discussions in 2010

Mesoscale Discussion 2113

December 3, 201012 counties in Iowa; 18 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at Dec 3, 2010, 10:13 AM CST for 12 counties in Iowa; 18 counties in Minnesota. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: Dec 3, 2010, 10:13 AM CST (16:13 UTC)
Expired: Dec 3, 2010, 2:15 PM CST
In force: 4 hr
Issued by: the Storm Prediction Center

All 30 counties

Black Hawk County, IA, Bremer County, IA, Butler County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Fayette County, IA, Floyd County, IA, Howard County, IA, Mitchell County, IA, Winnebago County, IA, Winneshiek County, IA, Worth County, IA, Blue Earth County, MN, Brown County, MN, Dodge County, MN, Faribault County, MN, Fillmore County, MN, Freeborn County, MN, Le Sueur County, MN, Martin County, MN, Mower County, MN, Nicollet County, MN, Olmsted County, MN, Redwood County, MN, Renville County, MN, Rice County, MN, Sibley County, MN, Steele County, MN, Waseca County, MN, Watonwan County, MN

The radar

The Minneapolis radar (KMPX), 122 km from the middle of the area, began a volume at 16:13 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 12:00Z, 4.2 hours before the alert went out and 122 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1097 m above ground
0-6 km bulk shear: 68 kt
0-1 km storm-relative helicity: 4 m²/s²
0-3 km storm-relative helicity: 161 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.

130 
ACUS11 KWNS 031614
SWOMCD
SPC MCD 031613
MNZ000-IAZ000-032015-

MESOSCALE DISCUSSION 2113
NWS STORM PREDICTION CENTER NORMAN OK
1013 AM CST FRI DEC 03 2010

AREAS AFFECTED...SRN MN AND NCNTRL/NERN IA

CONCERNING...HEAVY SNOW

VALID 031613Z - 032015Z

INITIAL BAND OF 700-500 MB FRONTOGENESIS WAS LARGELY RESPONSIBLE FOR
THE NARROW CORRIDOR OF SNOW PROGRESSING EWD ACROSS SRN MN AND NRN IA
LATE THIS MORNING.  12Z NAM...09Z SREF AND 14Z 3KM WRF-HRRR SUGGEST
THAT ISENTROPIC ASCENT IN THE 285-290K LAYER WILL INCREASE
SUBSTANTIALLY AFTER 21Z AS A WEAK UPPER IMPULSE MOVES SEWD TOWARD
THE REGION. AT THAT TIME...FRONTOGENESIS OVER A DEEPER LAYER WILL
BECOME COINCIDENT WITH A WEAKLY NEGATIVE EPV ZONE ATOP AND THE BANDS
OF SNOW WILL NARROW AND INTENSIFY.  BY THAT TIME...THE COLUMN WILL
HAVE BECOME MORE SATURATED AND ABOUT A 100 MB DEEP LAYER OF FAVORED
DENDRITIC ZONE SHOULD HAVE EVOLVED.  GIVEN ABOUT 12:1 SNOW
RATIOS...ONE INCH PER HOUR SNOW RATES WILL EASILY BE REACHED...BUT
OVER A NARROW ZONE.  LATEST GUIDANCE SUGGESTS THAT THIS CORRIDOR MAY
BE SLIGHTLY FARTHER SW THAN EARLIER EXPECTED.  HIGHEST PROBABILITIES
WILL BE IN AN AREA ROUGHLY 60-80 MILES WIDE CENTERED FROM JUST NW OF
REDWOOD FALLS MN TO 40NM W OF ROCHESTER MN TO 35NM NE OF WATERLOO IA
THROUGH MID-EVENING.

..RACY.. 12/03/2010

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

ATTN...WFO...DVN...ARX...MPX...DMX...FSD...

LAT...LON   44499327 43789183 42649168 42459236 42859336 43319403
            43999514 44719550 44849475 44499327

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 3, 5:50 PM CST	Mesoscale Discussion	SPC	Allamakee, Chickasaw, Clayton, Delaware, Dubuque, Fayette and 4 more	5 hr

Nearby

Mesoscale Discussions in Minnesota, 2010 Mesoscale Discussions in Iowa, 2010 Every mesoscale discussion in 2010

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.