Alert archive / Wisconsin / Mesoscale Discussions in 2014

Mesoscale Discussion 1613

August 25, 201414 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Aug 25, 2014, 6:17 AM CDT for 14 counties in Wisconsin. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued: Aug 25, 2014, 6:17 AM CDT (11:17 UTC)
Expired: Aug 25, 2014, 7:45 AM CDT
In force: 88 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Columbia County, WI, Dane County, WI, Dodge County, WI, Fond du Lac County, WI, Green County, WI, Green Lake County, WI, Jefferson County, WI, Marquette County, WI, Milwaukee County, WI, Rock County, WI, Walworth County, WI, Washington County, WI, Waukesha County, WI, Winnebago County, WI

The radar

The Milwaukee radar (KMKX), 50 km from the middle of the area, began a volume at 11:18 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

Green Bay/Straub, WI (KGRB), launched 00:00Z, 11.3 hours before the alert went out and 156 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: 168 J/kg
Mixed-layer CIN: -314 J/kg
Mixed-layer LCL: 965 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 112 m²/s²
0-3 km storm-relative helicity: 136 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.

753 
ACUS11 KWNS 251117
SWOMCD
SPC MCD 251117 
WIZ000-ILZ000-251245-

MESOSCALE DISCUSSION 1613
NWS STORM PREDICTION CENTER NORMAN OK
0617 AM CDT MON AUG 25 2014

AREAS AFFECTED...SERN WI

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 251117Z - 251245Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...STRONG WIND GUSTS MAY PRODUCE LOCALIZED DAMAGING WINDS FOR
A FEW MORE HOURS WITH STORM CLUSTERS PROGRESSING E/NE FROM SW WI/FAR
NE IA.

DISCUSSION...MERGING CLUSTERS HAVE SUPPORTED AN INCREASE IN FORWARD
SPEED AND BULGING REFLECTIVITY STRUCTURE FROM JUNEAU TO IOWA COUNTY
WI. THIS HAS ENHANCED DOWNDRAFT MOMENTUM AND YIELDED A STRONG WIND
GUST MEASURED AT KLNR OF 44 KT. ALTHOUGH SCATTERERS ARE FEW AND FAR
BETWEEN IN DVN/MKX VWP DATA...LSE SAMPLED 50 KT WLYS FROM 3-6 KM AGL
IN THE WAKE OF THE CLUSTER. THIS SHOULD HELP MAINTAIN FORWARD
MOMENTUM AS THE LEADING EDGE OF THE CLUSTER PROGRESSES ACROSS THE
NRN PERIPHERY OF AN AIR MASS THAT HAS YET NOT BEEN OVERTURNED THIS
MORNING...CHARACTERIZED BY MIDDLE TO UPPER 70S SURFACE TEMPERATURES
AND 72-76 DEG F DEW POINTS. THIS MAY YIELD A BIT LONGER DURATION OF
STRONG GUST POTENTIAL FARTHER E TOWARDS LK MICHIGAN...COMPARED TO
THE RAPID DEMISE OF AN EARLIER CLUSTER NEAR KGRB.

..GRAMS/CORFIDI.. 08/25/2014

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

ATTN...WFO...GRB...LOT...MKX...DVN...ARX...

LAT...LON   43858983 44078892 44138838 43948802 43648790 43178783
            42868784 42588818 42488907 42408989 42549020 42819001
            43128987 43368973 43858983

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 24, 9:34 PM CDT	Mesoscale Discussion	SPC	Burnett, Pierce, Polk, Saint Croix	56 min

Nearby

Mesoscale Discussions in Wisconsin, 2014 Every mesoscale discussion in 2014

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.