Alert archive / Wisconsin / Mesoscale Discussions in 2003

Mesoscale Discussion 1921

July 20, 20039 counties in Michigan; Lake County, Saint Louis County, Minnesota; 13 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jul 20, 2003, 7:47 PM EDT for 9 counties in Michigan; Lake County, Saint Louis County, Minnesota; 13 counties in Wisconsin. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued
Jul 20, 2003, 7:47 PM EDT (23:47 UTC)
Expired
Jul 20, 2003, 9:15 PM EDT
In force
88 min
Issued by
the Storm Prediction Center
All 24 counties

Baraga County, MI, Delta County, MI, Dickinson County, MI, Gogebic County, MI, Houghton County, MI, Iron County, MI, Marquette County, MI, Menominee County, MI, Ontonagon County, MI, Lake County, MN, Saint Louis County, MN, Ashland County, WI, Bayfield County, WI, Door County, WI, Douglas County, WI, Florence County, WI, Forest County, WI, Iron County, WI, Langlade County, WI, Marinette County, WI, Oneida County, WI, Price County, WI, Sawyer County, WI, Vilas County, WI

The radar

The Marquette radar (KMQT), 159 km from the middle of the area, began a volume at 23:50 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 12:00Z, 11.8 hours before the alert went out and 244 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, Green Bay/Straub, WI at 12:00Z on 2003-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 765 joules per kilogram.LCLLFCEL10008507005003002001001 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, Green Bay/Straub, WI at 12:00Z on 2003-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 51 square meters per square second.1939587897Sfc1 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
765 J/kg
Mixed-layer CIN
-74 J/kg
Mixed-layer LCL
716 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
51 m²/s²
0-3 km storm-relative helicity
110 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.5

Open this sounding in Storm Lab

The text

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

796 
ACUS11 KWNS 202347
SWOMCD
SPC MCD 202347 
MIZ000-WIZ000-MNZ000-210115-

MESOSCALE DISCUSSION 1921
NWS STORM PREDICTION CENTER NORMAN OK
0647 PM CDT SUN JUL 20 2003

AREAS AFFECTED...NERN MN...NRN WI AND UPPER MI

CONCERNING...SEVERE THUNDERSTORM WATCH 772...

VALID 202347Z - 210115Z

THREAT FOR LARGE HAIL AND ISOLATED DAMAGING WIND EXPECTED TO PERSIST
NEXT 2-3 HOURS.

NUMEROUS STORMS CONTINUE DEVELOPING WITHIN ZONE OF ASCENT IN EXIT
REGION OF CYCLONICALLY CURVED UPPER JET WHERE MID LEVEL LAPSE RATES
HAVE BEEN STEEPENED BY COLDER AIR ALOFT. UNIDIRECTIONAL WNWLY SHEAR
PROFILES WILL CONTINUE TO SUPPORT ORGANIZED STORMS INCLUDING
SUPERCELLS AND POTENTIAL FOR SMALL BOWING SEGMENTS. ACTIVITY SHOULD
BEGIN TO DECREASE IN INTENSITY LATER THIS EVENING WITH LOSS OF
HEATING.

..DIAL.. 07/20/2003

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

ATTN...WFO...MQT...GRB...DLH...

45508996 45929173 46179259 46979263 47669257 48089247
47809127 47478996 47028843 46638691 46398636 45588648
44778646 44538649

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 20, 1:41 PM EDTMesoscale DiscussionSPCBarry, Branch, Calhoun, Eaton, Hillsdale, Ingham and 6 more64 min
Jul 20, 2:16 PM EDTMesoscale DiscussionSPCAlger, Baraga, Dickinson, Gogebic, Houghton, Iron and 3 more119 min
Jul 20, 2:20 PM EDTSevere Thunderstorm WatchSPCAlcona, Alpena, Arenac, Bay, Clare, Clinton and 28 more6 hr
Jul 20, 2:55 PM EDTSevere Thunderstorm WatchSPCAlger, Baraga, Delta, Dickinson, Gogebic, Houghton and 4 more7 hr
Jul 20, 4:27 PM EDTMesoscale DiscussionSPCAlger, Baraga, Delta, Dickinson, Gogebic, Houghton and 4 more63 min
Jul 20, 4:37 PM EDTMesoscale DiscussionSPCAlcona, Alpena, Arenac, Bay, Crawford, Genesee and 21 more113 min
Jul 20, 7:23 PM EDTMesoscale DiscussionSPCBerrien, Cass, Saint Joseph, Van Buren97 min
Jul 20, 7:45 PM EDTSevere Thunderstorm WatchSPCAllegan, Antrim, Barry, Benzie, Berrien, Branch and 27 more5 hr
Jul 19, 8:16 PM EDTMesoscale DiscussionSPCBeltrami, Clearwater, Itasca, Kittson, Koochiching, Marshall and 5 more89 min
Jul 20, 12:00 AM EDTSevere Thunderstorm WatchSPCBecker, Beltrami, Clay, Clearwater, Hubbard, Mahnomen and 7 more5 hr
Jul 20, 2:15 AM EDTSevere Thunderstorm WatchSPCBig Stone, Chippewa, Cottonwood, Douglas, Grant, Jackson and 15 more6 hr
Jul 20, 3:03 AM EDTMesoscale DiscussionSPCBig Stone, Chippewa, Grant, Lac qui Parle, Lincoln, Lyon and 6 more117 min
Jul 20, 4:05 AM EDTSevere Thunderstorm WatchSPCBecker, Clay, Grant, Norman, Otter Tail, Wilkin4 hr
Jul 20, 5:14 AM EDTMesoscale DiscussionSPCBlue Earth, Brown, Carver, Chippewa, Cottonwood, Dakota and 34 more3 hr
Jul 20, 7:45 AM EDTSevere Thunderstorm WatchSPCBlue Earth, Brown, Cottonwood, Faribault, Freeborn, Jackson and 15 more5 hr
Jul 20, 11:07 AM EDTMesoscale DiscussionSPCCottonwood, Jackson, Lincoln, Lyon, Murray, Nobles and 3 more53 min
Jul 20, 6:14 PM EDTMesoscale DiscussionSPCLincoln, Lyon, Murray, Pipestone, Rock, Yellow Medicine2 hr
Jul 20, 5:25 PM EDTSevere Thunderstorm WatchSPCBrown, Calumet, Columbia, Dane, Dodge, Fond du Lac and 19 more5 hr

Nearby

Mesoscale Discussions in Wisconsin, 2003Mesoscale Discussions in Michigan, 2003Mesoscale Discussions in Minnesota, 2003Every mesoscale discussion in 2003

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.