Alert archive / Minnesota / Mesoscale Discussions in 2012

Mesoscale Discussion 165

February 28, 201224 counties in Minnesota; 18 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Feb 28, 2012, 2:40 PM CST for 24 counties in Minnesota; 18 counties in Wisconsin. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: Feb 28, 2012, 2:40 PM CST (20:40 UTC)
Expired: Feb 28, 2012, 6:45 PM CST
In force: 4 hr
Issued by: the Storm Prediction Center

All 42 counties

Anoka County, MN, Benton County, MN, Carver County, MN, Chisago County, MN, Dakota County, MN, Dodge County, MN, Goodhue County, MN, Hennepin County, MN, Houston County, MN, Isanti County, MN, Kanabec County, MN, Le Sueur County, MN, McLeod County, MN, Mille Lacs County, MN, Olmsted County, MN, Ramsey County, MN, Rice County, MN, Scott County, MN, Sherburne County, MN, Steele County, MN, Wabasha County, MN, Washington County, MN, Winona County, MN, Wright County, MN, Barron County, WI, Buffalo County, WI, Chippewa County, WI, Clark County, WI, Dunn County, WI, Eau Claire County, WI, Jackson County, WI, Juneau County, WI, La Crosse County, WI, Monroe County, WI, Pepin County, WI, Pierce County, WI, Polk County, WI, Richland County, WI, Saint Croix County, WI, Sauk County, WI, Trempealeau County, WI, Vernon County, WI

The radar

The La Crosse radar (KARX), 118 km from the middle of the area, began a volume at 20:41 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 nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 8.7 hours before the alert went out and 121 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: 1485 m above ground
0-6 km bulk shear: 64 kt
0-1 km storm-relative helicity: 279 m²/s²
0-3 km storm-relative helicity: 363 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.

762 
ACUS11 KWNS 282041
SWOMCD
SPC MCD 282040
WIZ000-IAZ000-MNZ000-290045-

MESOSCALE DISCUSSION 0165
NWS STORM PREDICTION CENTER NORMAN OK
0240 PM CST TUE FEB 28 2012

AREAS AFFECTED...E-CNTRL MN...W CNTRL WI

CONCERNING...WINTER MIXED PRECIPITATION

VALID 282040Z - 290045Z

WINTER MIXED PRECIPITATION IS EXPECTED TO INCREASE ACROSS PORTIONS
OF E-CNTRL MN AND W-CNTRL WI DURING THE LATE AFTERNOON AND EVENING.
THIS INCLUDES AREAS OF FREEZING RAIN RATES OF 0.05 TO 0.10 IN/HR.

AN AREA OF MIXED PRECIP ACROSS SERN MN...SRN WI...AND NERN/N-CNTRL
IA WILL CONTINUE TO PROGRESS NEWD OVER THE NEXT FEW HOURS...WITH
ADDITIONAL PRECIP DEVELOPING FARTHER SW INTO NEB/SD. AREA VWP DATA
INDICATE 20 TO 30 KT S WINDS NEAR 3 KM AGL...WHICH WILL STRENGTHEN
THE ELEVATED WARM NOISE VIA WAA. SEVERAL DETERMINISTIC MODEL RUNS --
E.G. NAM/ETA-KF CONTROL MEMBER OF THE SREF/RUC -- AS WELL AS
HIGH-RESOLUTION WRF MODEL OUTPUT ARE HAVING DIFFICULTLY RESOLVING
THE COMPLEX SFC TEMPERATURE FIELD ACROSS MUCH OF THE AREA...WITH
MODEL OUTPUT SUGGESTING WARMER SFC TEMPERATURES THAN THOSE OBSERVED.
AS A RESULT...MUCH OF THIS MODEL OUTPUT INDICATES RAIN WOULD OCCUR
WHILE OBSERVATIONS SUGGEST MIXED PRECIP IS MORE LIKELY.
FURTHERMORE...FRONTOGENESIS WILL INCREASE ACROSS THE AREA AS A SFC
LOW MOVES NEWD THIS EVENING. THIS WILL LIKELY RESULT IN AN INCREASE
OF PRECIP INTENSITY AND COVERAGE. FREEZING RAIN...SLEET...AND SNOW
WILL ALL BE POSSIBLE...WITH THE THREAT FOR FREEZING RAIN BECOMING OF
INCREASING CONCERN AFTER 23Z CONTINUING INTO THE EVENING. FREEZING
RAIN RATES OF 0.05 TO 0.10 IN/HR POSSIBLE...HIGHEST NEAR EMBEDDED
ELEVATED CONVECTIVE ELEMENTS /WITH ISOLATED LIGHTNING STRIKES
POSSIBLE/.

..MOSIER/COHEN.. 02/28/2012

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

ATTN...WFO...GRB...MKX...DLH...ARX...MPX...

LAT...LON   45919304 45759234 45489166 45229107 44779022 44078982
            43598976 43359003 43249060 43269108 43579152 43759225
            43909310 44209384 45099450 45699447 45859404 45989338
            45919304

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 28, 6:18 AM CST	Mesoscale Discussion	SPC	Jackson, Nobles, Rock	5 hr
Feb 28, 11:43 AM CST	Mesoscale Discussion	SPC	Big Stone, Brown, Carver, Chippewa, Cottonwood, Jackson and 21 more	5 hr
Feb 28, 2:43 PM CST	Mesoscale Discussion	SPC	Becker, Clay, Crow Wing, Douglas, Grant, Morrison and 6 more	5 hr

Nearby

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