Alert archive / Iowa / Mesoscale Discussions in 2004

Mesoscale Discussion 970

May 28, 200422 counties in Iowa; 18 counties in Minnesota; 18 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at May 28, 2004, 11:41 PM CDT for 22 counties in Iowa; 18 counties in Minnesota; 18 counties in South Dakota. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued
May 28, 2004, 11:41 PM CDT (04:41 UTC)
Expired
May 29, 2004, 1:15 AM CDT
In force
94 min
Issued by
the Storm Prediction Center
All 58 counties

Buena Vista County, IA, Calhoun County, IA, Cherokee County, IA, Clay County, IA, Dickinson County, IA, Emmet County, IA, Hamilton County, IA, Hancock 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, Wright County, IA, Big Stone County, MN, Brown County, MN, Chippewa County, MN, Cottonwood County, MN, Jackson County, MN, Lac qui Parle County, MN, Lincoln County, MN, Lyon County, MN, Martin County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Redwood County, MN, Renville County, MN, Rock County, MN, Swift County, MN, Watonwan County, MN, Yellow Medicine County, MN, Beadle County, SD, Brookings County, SD, Clark County, SD, Clay County, SD, Codington County, SD, Day County, SD, Deuel County, SD, Grant County, SD, Hamlin County, SD, Kingsbury County, SD, Lake County, SD, Lincoln County, SD, McCook County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Turner County, SD, Union County, SD

The radar

The Sioux Falls radar (KFSD), 59 km from the middle of the area, began a volume at 04:42 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

Aberdeen, SD (KABR), launched 00:00Z, 4.7 hours before the alert went out and 220 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, Aberdeen, SD at 00:00Z on 2004-05-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 48 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Aberdeen, SD at 00:00Z on 2004-05-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 46 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
48 J/kg
Mixed-layer CIN
-105 J/kg
Mixed-layer LCL
1790 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
46 m²/s²
0-3 km storm-relative helicity
242 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

823 
ACUS11 KWNS 290441
SWOMCD
SPC MCD 290441 
IAZ000-MNZ000-NEZ000-SDZ000-290615-

MESOSCALE DISCUSSION 0970
NWS STORM PREDICTION CENTER NORMAN OK
1141 PM CDT FRI MAY 28 2004

AREAS AFFECTED...ERN SD...SWRN MN AND NWRN/CNTRL IA

CONCERNING...SEVERE THUNDERSTORM WATCH 320...

VALID 290441Z - 290615Z

TSTMS MAY PRODUCE LARGE HAIL ACROSS ERN SD...SWRN MN AND NWRN/CNTRL
IA THROUGH THE EARLY MORNING HOURS OF SATURDAY.  ISOLD DAMAGING
WINDS MAY ALSO OCCUR ACROSS PARTS OF CNTRL IA.

PROFILER/VAD WIND PROFILER DATA SUGGEST THAT THE SLY LOW LEVEL JET
HAS INCREASED TO NEARLY 60 KTS...SIMILAR TO LATEST RUC FORECAST.  AN
IMPRESSIVE WARM ADVECTION REGIME ON THE NOSE OF THIS JET HAS BEEN
SUPPORTING TSTMS...ESPECIALLY FROM NEAR WATERTOWN SEWD TOWARD FT.
DODGE AND CARROLL IA.  PARCELS FEEDING THE TSTMS EXHIBIT MUCAPE
VALUES OF AROUND 1500 J/KG PER OBJECTIVE ANALYSIS AND GIVEN 45-50
KTS OF CAPE-BEARING SHEAR...POTENTIAL WILL EXIST FOR A FEW ELEVATED
SUPERCELLS WITH LARGE HAIL.

ADDITIONALLY...WHAT WERE SUPERCELLS EARLIER THIS EVENING IN THE
SIOUX FALLS/SIOUX CITY AREAS HAVE EVOLVED INTO SMALL SCALE BOWS AND
ARE MOVING INTO WCNTRL IA.  THESE CELLS...WHILE PROBABLY ELEVATED
ABOVE THE BOUNDARY LAYER...WILL CONTINUE TO HAVE A SMALL DAMAGING
WIND PROBABILITY.

TSTMS ARE EXPECTED TO DEVELOP NWD INTO POSSIBLY WCNTRL MN SEWD INTO
NCNTRL IA IN A FEW HOURS.

..RACY.. 05/29/2004

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

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

42109623 44429837 45469761 45729628 44929470 42099312

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 28, 7:31 PM CDTMesoscale DiscussionSPCCherokee, Crawford, Harrison, Ida, Lyon, Monona and 6 more89 min
May 28, 9:03 PM CDTMesoscale DiscussionSPCAudubon, Buena Vista, Calhoun, Carroll, Cherokee, Clay and 24 more57 min
May 28, 9:50 PM CDTSevere Thunderstorm WatchSPCBuena Vista, Calhoun, Cherokee, Clay, Dickinson, Emmet and 15 more5 hr
May 29, 12:42 PM CDTMesoscale DiscussionSPCAdair, Appanoose, Audubon, Boone, Buena Vista, Calhoun and 45 more93 min
May 29, 2:05 PM CDTTornado WatchSPCBuena Vista, Calhoun, Cherokee, Clay, Dickinson, Emmet and 13 more8 hr
May 29, 3:05 PM CDTTornado WatchSPCCarroll, Crawford, Fremont, Harrison, Mills, Monona and 4 more7 hr
May 29, 4:35 PM CDTTornado WatchSPCAdair, Adams, Boone, Cass, Clarke, Dallas and 15 more5 hr
May 29, 5:01 PM CDTMesoscale DiscussionSPCBuena Vista, Calhoun, Cherokee, Clay, Dickinson, Emmet and 13 more119 min
May 29, 3:25 PM CDTSevere Thunderstorm WatchSPCBecker, Clay, Douglas, Grant, Norman, Otter Tail and 2 more6 hr

Nearby

Mesoscale Discussions in Iowa, 2004Mesoscale Discussions in Minnesota, 2004Mesoscale Discussions in South Dakota, 2004Every mesoscale discussion in 2004

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.