Alert archive / Iowa / Mesoscale Discussions in 2003

Mesoscale Discussion 1908

July 20, 200319 counties in Iowa; 9 counties in Minnesota; 6 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 20, 2003, 10:07 AM CDT for 19 counties in Iowa; 9 counties in Minnesota; 6 counties in South Dakota. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
Jul 20, 2003, 10:07 AM CDT (15:07 UTC)
Expired
Jul 20, 2003, 11:00 AM CDT
In force
53 min
Issued by
the Storm Prediction Center
All 34 counties

Buena Vista County, IA, Calhoun County, IA, Cherokee County, IA, Clay County, IA, Dickinson County, IA, Emmet County, IA, Humboldt County, IA, Ida County, IA, Kossuth County, IA, Lyon County, IA, O'Brien County, IA, Osceola County, IA, Palo Alto County, IA, Plymouth County, IA, Pocahontas County, IA, Sac County, IA, Sioux County, IA, Webster County, IA, Woodbury County, IA, Cottonwood County, MN, Jackson County, MN, Lincoln County, MN, Lyon County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Redwood County, MN, Rock County, MN, Brookings County, SD, Kingsbury County, SD, Lake County, SD, Lincoln County, SD, Minnehaha County, SD, Moody County, SD

The radar

The Sioux Falls radar (KFSD), 101 km from the middle of the area, began a volume at 15:07 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, 3.1 hours before the alert went out and 212 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, Minneapolis, MN at 12:00Z on 2003-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 189 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, Minneapolis, MN at 12:00Z on 2003-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 36 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
189 J/kg
Mixed-layer CIN
-312 J/kg
Mixed-layer LCL
1802 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
36 m²/s²
0-3 km storm-relative helicity
87 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.

065 
ACUS11 KWNS 201507
SWOMCD
SPC MCD 201507 
IAZ000-MNZ000-SDZ000-201600-

MESOSCALE DISCUSSION 1908
NWS STORM PREDICTION CENTER NORMAN OK
1007 AM CDT SUN JUL 20 2003

AREAS AFFECTED...SERN SD...SWRN MN...NWRN IA

CONCERNING...SEVERE THUNDERSTORM WATCH 770...

VALID 201507Z - 201600Z

...CONVECTION WILL CONTINUE TO DEVELOP ACROSS WRN PORTIONS OF WW...

NWLY WARM ADVECTION FEED ATOP THE BOUNDARY LAYER APPEARS TO BE
DRIVING RENEWED THUNDERSTORM DEVELOPMENT ACROSS WRN PORTIONS OF
WW...MAINLY ON BACK SIDE OF CONVECTIVE BUBBLE HIGH.  CLOUD LAYER
SHEAR IS NOT PARTICULARLY STRONG AND GIVEN NATURE OF ONGOING
ACTIVITY...IT MOST LIKELY FALLS IN THE PULSE-MULTICELL STORM
STRUCTURE.  UNLESS THUNDERSTORMS CAN TRANSITION INTO A
FORWARD-PROPAGATING MODE...MARGINAL SEVERE HAIL SHOULD BE THE
PRIMARY CONCERN IN THE NEAR TERM.

..DARROW.. 07/20/2003

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

ATTN...WFO...MPX...DMX...FSD...ABR...

44769545 42749378 42009450 42349607 44429760

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 20, 4:14 AM CDTMesoscale DiscussionSPCHoward, Mitchell, Winnebago, Winneshiek, Worth3 hr
Jul 20, 6:45 AM CDTSevere Thunderstorm WatchSPCBuena Vista, Butler, Calhoun, Cerro Gordo, Cherokee, Clay and 22 more5 hr
Jul 20, 2:09 PM CDTMesoscale DiscussionSPCCrawford, Harrison, Monona, Plymouth, Pottawattamie, Shelby and 2 more66 min
Jul 20, 2:50 PM CDTTornado WatchSPCAdair, Adams, Audubon, Buena Vista, Carroll, Cass and 20 more6 hr
Jul 20, 5:29 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Carroll, Cass, Cherokee and 17 more91 min
Jul 19, 7:16 PM CDTMesoscale DiscussionSPCBeltrami, Clearwater, Itasca, Kittson, Koochiching, Marshall and 5 more89 min
Jul 19, 11:00 PM CDTSevere Thunderstorm WatchSPCBecker, Beltrami, Clay, Clearwater, Hubbard, Mahnomen and 7 more5 hr
Jul 20, 1:15 AM CDTSevere Thunderstorm WatchSPCBig Stone, Chippewa, Cottonwood, Douglas, Grant, Jackson and 15 more6 hr
Jul 20, 2:03 AM CDTMesoscale DiscussionSPCBig Stone, Chippewa, Grant, Lac qui Parle, Lincoln, Lyon and 6 more117 min
Jul 20, 3:05 AM CDTSevere Thunderstorm WatchSPCBecker, Clay, Grant, Norman, Otter Tail, Wilkin4 hr
Jul 20, 1:16 PM CDTMesoscale DiscussionSPCBeltrami, Cook, Itasca, Koochiching, Lake, Lake of the Woods and 2 more119 min
Jul 20, 1:55 PM CDTSevere Thunderstorm WatchSPCCarlton, Lake, Saint Louis7 hr
Jul 20, 3:27 PM CDTMesoscale DiscussionSPCCarlton, Lake, Saint Louis63 min
Jul 20, 5:14 PM CDTMesoscale DiscussionSPCLincoln, Lyon, Murray, Pipestone, Rock, Yellow Medicine2 hr
Jul 20, 6:47 PM CDTMesoscale DiscussionSPCLake, Saint Louis88 min
Jul 19, 11:58 PM CDTMesoscale DiscussionSPCBrown, Clark, Codington, Day, Deuel, Edmunds and 6 more62 min

Nearby

Mesoscale Discussions in Iowa, 2003Mesoscale Discussions in Minnesota, 2003Mesoscale Discussions in South Dakota, 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.