Alert archive / Iowa / Mesoscale Discussions in 2005

Mesoscale Discussion 430

March 30, 200538 counties in Iowa; 22 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at Mar 30, 2005, 6:03 AM CST for 38 counties in Iowa; 22 counties in Minnesota. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
Mar 30, 2005, 6:03 AM CST (12:03 UTC)
Expired
Mar 30, 2005, 8:00 AM CST
In force
117 min
Issued by
the Storm Prediction Center
All 60 counties

Adair County, IA, Adams County, IA, Audubon County, IA, Boone County, IA, Buena Vista County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Cherokee County, IA, Clay County, IA, Crawford County, IA, Dallas County, IA, Dickinson County, IA, Emmet County, IA, Greene County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Harrison County, IA, Humboldt County, IA, Ida County, IA, Kossuth County, IA, Mills County, IA, Monona County, IA, Montgomery County, IA, O'Brien County, IA, Osceola County, IA, Palo Alto County, IA, Plymouth County, IA, Pocahontas County, IA, Pottawattamie County, IA, Sac County, IA, Shelby County, IA, Sioux County, IA, Webster County, IA, Winnebago County, IA, Woodbury County, IA, Wright County, IA, Blue Earth County, MN, Brown County, MN, Carver County, MN, Cottonwood County, MN, Faribault County, MN, Freeborn County, MN, Hennepin County, MN, Jackson County, MN, Le Sueur County, MN, Martin County, MN, McLeod County, MN, Meeker County, MN, Nicollet County, MN, Nobles County, MN, Redwood County, MN, Renville County, MN, Rice County, MN, Scott County, MN, Sibley County, MN, Steele County, MN, Waseca County, MN, Watonwan County, MN

The radar

The Des Moines radar (KDMX), 136 km from the middle of the area, began a volume at 12:05 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 0.1 hours before the alert went out and 199 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, Omaha, NE at 12:00Z on 2005-03-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 585 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, Omaha, NE at 12:00Z on 2005-03-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 23 square meters per square second.193958Sfc1 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
585 J/kg
Mixed-layer CIN
-92 J/kg
Mixed-layer LCL
916 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
23 m²/s²
0-3 km storm-relative helicity
61 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.

000 
ACUS11 KWNS 301203
SWOMCD
SPC MCD 301203 
MNZ000-IAZ000-301400-

MESOSCALE DISCUSSION 0430
NWS STORM PREDICTION CENTER NORMAN OK
0603 AM CST WED MAR 30 2005

AREAS AFFECTED...WRN/CNTRL IA AND SCNTRL MN

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 301203Z - 301400Z

TSTMS ARE LIKELY TO INCREASE THROUGH MID-MORNING ACROSS WRN/CNTRL IA
AND SCNTRL MN. THREATS FOR LARGE HAIL AND DAMAGING WINDS WILL EXIST
AND A SEVERE TSTM WATCH MAY BECOME NECESSARY.

WATER VAPOR LOOPS SHOW THAT THE STRONG UPPER LOW WAS MOVING SLOWLY
EWD THROUGH NERN KS WITH AN ENHANCED JET STREAK CURVING NEWD THROUGH
WRN MO.  LARGE SCALE FORCING FOR ASCENT WAS BEGINNING TO SPREAD NEWD
ACROSS THE MO RVR AND RECENT TSTM DEVELOPMENT VCNTY KOMA MAY BE THE
START OF A MORE ORGANIZED BATCH OF STORMS.

00Z WRF AND 09Z RUC AGREE IN TSTMS DEVELOPING ALONG THE MO RVR BY
12Z...WITH STORMS THEN MOVING/DEVELOPING NWD INTO PARTS OF CNTRL/NRN
IA AND SCNTRL MN.  A SMALL WARM SECTOR HAS EVOLVED OVER THIS AREA
AND GIVEN MID 50S/MID 40S TEMPERATURES/DEW POINTS... MUCAPE OF
AROUND 750 J/KG IS LIKELY IN PLACE.  MAGNITUDE OF FORCING WILL BE
SUFFICIENT FOR THE INCREASING TSTM THREAT.

VERTICAL SHEAR IN THE CAPE-BEARING LAYER WILL BE MARGINALLY
SUFFICIENT FOR SUPERCELLULAR STRUCTURES AND GIVEN THE STEEPENING
MID-TROP LAPSE RATES...LARGE HAIL WILL BE A CONCERN.  DAMAGING WINDS
MAY ALSO BECOME MORE OF A THREAT AS STORMS DEVELOP...CONGEAL AND
BEGIN TO ORIENT NORMAL TO THE MEAN WIND VECTORS.

TSTMS MAY TEND TO DEVELOP FARTHER SWD LATER THIS MORNING INTO SCNTRL
IA AS THE BOUNDARY LAYER BEGINS TO WARM AND THE LARGE SCALE FORCING
SPREADS FARTHER TO THE EAST.

..RACY.. 03/30/2005

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

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

41089578 42369615 42849645 45179483 45149343 44079314
42689357 41589395 40689483

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 30, 8:40 AM CSTSevere Thunderstorm WatchSPCAdair, Adams, Audubon, Boone, Butler, Calhoun and 38 more5 hr
Mar 30, 10:46 AM CSTMesoscale DiscussionSPCAllamakee, Appanoose, Benton, Black Hawk, Bremer, Buchanan and 29 more119 min
Mar 30, 10:50 AM CSTMesoscale DiscussionSPCAdair, Adams, Audubon, Boone, Calhoun, Carroll and 29 more85 min
Mar 30, 11:05 AM CSTTornado WatchSPCAllamakee, Appanoose, Benton, Black Hawk, Bremer, Buchanan and 28 more5 hr
Mar 30, 1:14 PM CSTMesoscale DiscussionSPCBoone, Butler, Cerro Gordo, Floyd, Franklin, Hamilton and 7 more61 min
Mar 30, 1:23 PM CSTMesoscale DiscussionSPCAllamakee, Benton, Black Hawk, Bremer, Buchanan, Cedar and 25 more97 min
Mar 30, 2:00 PM CSTMesoscale DiscussionSPCBoone, Butler, Cerro Gordo, Floyd, Franklin, Hamilton and 7 more30 min
Mar 30, 2:15 PM CSTTornado WatchSPCAllamakee, Benton, Black Hawk, Bremer, Buchanan, Butler and 20 more6 hr
Mar 30, 3:54 PM CSTMesoscale DiscussionSPCAllamakee, Clayton, Clinton, Dubuque, Jackson, Winneshiek66 min

Nearby

Mesoscale Discussions in Iowa, 2005Mesoscale Discussions in Minnesota, 2005Every mesoscale discussion in 2005

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.