Alert archive / Iowa / Mesoscale Discussions in 2011
Mesoscale Discussion 243
The Storm Prediction Center issued this mesoscale discussion at Mar 21, 2011, 10:05 PM CDT for 23 counties in Iowa; 8 counties in Minnesota; 23 counties in South Dakota. It was in force for 115 min.
The area
The outline as issued.
The facts
- Issued
- Mar 21, 2011, 10:05 PM CDT (03:05 UTC)
- Expired
- Mar 22, 2011, 12:00 AM CDT
- In force
- 115 min
- Issued by
- the Storm Prediction Center
All 54 counties
Buena Vista County, IA, Calhoun County, IA, Cherokee County, IA, Clay County, IA, Dickinson County, IA, Emmet County, IA, Greene 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, Winnebago County, IA, Worth County, IA, Wright County, IA, Cottonwood County, MN, Jackson County, MN, Lincoln County, MN, Martin County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Rock County, MN, Aurora County, SD, Beadle County, SD, Brookings County, SD, Brule County, SD, Buffalo County, SD, Clay County, SD, Davison County, SD, Douglas County, SD, Hand County, SD, Hanson County, SD, Hutchinson County, SD, Jerauld County, SD, Kingsbury County, SD, Lake County, SD, Lincoln County, SD, McCook County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Sanborn County, SD, Turner County, SD, Union County, SD, Yankton County, SD
The radar
The Sioux Falls radar (KFSD), 55 km from the middle of the area, began a volume at 03:06 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
Omaha, NE (KOAX), launched 00:00Z, 3.1 hours before the alert went out and 214 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 854 m above ground
- 0-6 km bulk shear
- 69 kt
- 0-1 km storm-relative helicity
- 536 m²/s²
- 0-3 km storm-relative helicity
- 656 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 8.0
The text
As transmitted, in the capitals the NWS used until 2016.
906
ACUS11 KWNS 220306
SWOMCD
SPC MCD 220305
IAZ000-MNZ000-SDZ000-220500-
MESOSCALE DISCUSSION 0243
NWS STORM PREDICTION CENTER NORMAN OK
1005 PM CDT MON MAR 21 2011
AREAS AFFECTED...CNTRL THROUGH NWRN IA...SERN SD AND SWRN MN
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 220305Z - 220500Z
STORMS ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSITY FROM SERN
SD THROUGH SWRN MN INTO NWRN AND CNTRL IA NEXT FEW HOURS. THE
STRONGER STORMS COULD EVENTUALLY POSE A THREAT FOR ISOLATED LARGE
HAIL. CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED FOR A POSSIBLE
SEVERE THUNDERSTORM WATCH.
LATE THIS EVENING A QUASI-STATIONARY FRONT EXTENDS FROM NRN MO WWD
THROUGH SRN NEB. THE SURFACE LAYER IS VERY STABLE NORTH OF THIS
FRONT WITH TEMPERATURES FROM THE UPPER 30S IN SWRN MN AND SERN SD TO
50S FARTHER SOUTH INTO IA AND NEB. HOWEVER...THETA-E ADVECTION ALONG
60 KT LLJ IS CONTRIBUTING TO NWD DESTABILIZATION ABOVE THE SURFACE
WITH MUCAPE FROM 1000-1500 J/KG FROM ERN NEB INTO WRN AND CNTRL IA.
SWLY FLOW ALOFT IS ADVECTING WARM AIR WITHIN BASE OF EML NEWD WITH
TIME...AND THIS WILL SERVE AS A CAP WHERE THE ATMOSPHERE IS
CURRENTLY MORE UNSTABLE FROM PORTIONS OF ERN NEB INTO SWRN IA.
RECENT RADAR TRENDS INDICATE CONVECTION IS BEGINNING TO DEVELOP
FARTHER NORTH FROM SERN SD INTO NWRN IA WHERE ISENTROPIC ASCENT HAS
BECOME SUFFICIENT TO BRING PARCELS TO THEIR LFC ALONG NRN EDGE OF
CAP. THESE STORMS MAY EVENTUALLY INTENSIFY AS THE ATMOSPHERE
DESTABILIZES NWD WITH TIME. EFFECTIVE SHEAR OF 40-50 KT WILL SUPPORT
A THREAT OF ELEVATED SUPERCELLS.
..DIAL.. 03/22/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MPX...DMX...FSD...ABR...
LAT...LON 41839423 42899702 43629945 44599928 44569632 43369321
41839423SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 22, 1:19 PM CDT | Mesoscale Discussion | SPC | Adams, Cass, Crawford, Fremont, Harrison, Mills and 7 more | 116 min |
| Mar 22, 2:03 PM CDT | Tornado Watch | SPC | Adair, Adams, Appanoose, Audubon, Boone, Calhoun and 38 more | 7 hr |
| Mar 22, 5:33 PM CDT | Mesoscale Discussion | SPC | Adair, Adams, Audubon, Cass, Harrison, Madison and 2 more | 57 min |
| Mar 22, 10:39 AM CDT | Mesoscale Discussion | SPC | Beltrami, Clearwater, Pennington, Polk, Red Lake | 6 hr |
| Mar 22, 2:25 PM CDT | Mesoscale Discussion | SPC | Big Stone, Douglas, Grant, Lac qui Parle, Otter Tail, Pope and 5 more | 4 hr |
| Mar 22, 3:49 PM CDT | Mesoscale Discussion | SPC | Aitkin, Carlton, Cass, Chisago, Crow Wing, Isanti and 4 more | 5 hr |
Nearby
Mesoscale Discussions in Iowa, 2011Mesoscale Discussions in South Dakota, 2011Mesoscale Discussions in Minnesota, 2011Every mesoscale discussion in 2011
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.