Alert archive / Iowa / Mesoscale Discussions in 2011
Mesoscale Discussion 154
The Storm Prediction Center issued this mesoscale discussion at Feb 27, 2011, 5:50 PM CST for 9 counties in Illinois; 25 counties in Iowa; Harrison County, Mercer County, Putnam County, Missouri. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 27, 2011, 5:50 PM CST (23:50 UTC)
- Expired
- Feb 27, 2011, 11:45 PM CST
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
All 37 counties
Appanoose County, IA, Cedar County, IA, Clarke County, IA, Clinton County, IA, Davis County, IA, Decatur County, IA, Des Moines County, IA, Henry County, IA, Iowa County, IA, Jackson County, IA, Jefferson County, IA, Johnson County, IA, Keokuk County, IA, Louisa County, IA, Lucas County, IA, Mahaska County, IA, Marion County, IA, Monroe County, IA, Muscatine County, IA, Ringgold County, IA, Scott County, IA, Van Buren County, IA, Wapello County, IA, Washington County, IA, Wayne County, IA, Bureau County, IL, Carroll County, IL, DeKalb County, IL, Henry County, IL, Lee County, IL, Mercer County, IL, Ogle County, IL, Rock Island County, IL, Whiteside County, IL, Harrison County, MO, Mercer County, MO, Putnam County, MO
The radar
The Quad Cities radar (KDVN), 110 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
Davenport, (KDVN), launched 12:00Z, 11.8 hours before the alert went out and 116 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
- 680 m above ground
- 0-6 km bulk shear
- 77 kt
- 0-1 km storm-relative helicity
- 106 m²/s²
- 0-3 km storm-relative helicity
- 172 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
800
ACUS11 KWNS 272351
SWOMCD
SPC MCD 272350
ILZ000-IAZ000-MOZ000-280545-
MESOSCALE DISCUSSION 0154
NWS STORM PREDICTION CENTER NORMAN OK
0550 PM CST SUN FEB 27 2011
AREAS AFFECTED...SERN IA...EXTREME NRN MO...NWRN/N-CNTRL IL
CONCERNING...WINTER MIXED PRECIPITATION
VALID 272350Z - 280545Z
A WINTRY MIX IS ANTICIPATED ACROSS PORTIONS OF SERN IA...EXTREME NRN
MO...AND NWRN/N-CNTRL IL THIS EVENING. FREEZING RAIN IS EXPECTED IN
THIS AREA...WITH RATES AOA 0.05 INCH PER HOUR POSSIBLE.
INCREASING ASCENT OVER THE CENTRAL PLAINS HAS AIDED IN INITIATING A
CONVECTIVE COMPLEX OVER PORTIONS OF NRN MO...WITH STRATIFORM PRECIP
CURRENTLY EXTENDING INTO SRN IA. AS THIS ACTIVITY IS STEERED NEWD
THIS EVENING...AND ADDITIONAL SCATTERED CONVECTION DEVELOPS UPSTREAM
OVER PORTIONS OF ERN KS...PRECIPITATION WILL CONTINUE TO INCREASE
ACROSS THE DISCUSSION AREA. OBJECTIVE ANALYSIS AT 23Z DEPICTS THE
SFC FREEZING LINE EXTENDING FROM NEAR DKB TO JUST NORTH OF LWD. COLD
AIR ADVECTION ACROSS THE REGION IS FORECAST TO NUDGE THE FREEZING
LINE SWD THIS EVENING. FREEZING RAIN WILL BE THE PRIMARY CONCERN
NORTH OF THIS LINE...GIVEN ELEVATED WARM NOSE TEMPERATURES AOA 3C
PER RUC FORECAST SOUNDINGS. HOWEVER...LATER IN THE
EVENING...ADDITIONAL LOW-LEVEL COOLING IS ANTICIPATED...WHICH COULD
ALLOW SLEET AND SNOW TO ALSO OCCUR. FREEZING RAIN RATES AOA 0.05
INCH PER HOUR WILL BE POSSIBLE...ESPECIALLY ACROSS PORTIONS OF SERN
IA AND NWRN/N-CNTRL IL WHERE THE PRESENCE OF ELEVATED INSTABILITY
COULD ENHANCE UPRIGHT CONVECTION IN ADDITIONAL TO THUNDERSTORM
ACTIVITY. MOST OF THE PRECIPITATION IS EXPECTED TO HAVE MOVED EWD
INTO IL BY 07Z.
..COHEN.. 02/27/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LOT...ILX...DVN...DMX...EAX...
LAT...LON 40239361 40729142 41448895 41768852 42258888 42369029
41769220 41359343 40819445 40249418 40239361SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 27, 4:57 PM CST | Mesoscale Discussion | SPC | Alexander, Franklin, Hardin, Jackson, Jefferson, Johnson and 11 more | 2 hr |
| Feb 27, 5:10 PM CST | Mesoscale Discussion | SPC | Adams, Pike | 35 min |
| Feb 27, 5:33 PM CST | Severe Thunderstorm Watch | SPC | Adams, Brown, Cass, DeWitt, Fulton, Logan and 12 more | 4 hr |
| Feb 27, 12:44 PM CST | Mesoscale Discussion | SPC | Pemiscot | 91 min |
| Feb 27, 12:46 PM CST | Mesoscale Discussion | SPC | Caldwell, Carroll, Cass, Chariton, Clay, Clinton and 7 more | 59 min |
| Feb 27, 1:12 PM CST | Severe Thunderstorm Watch | SPC | Bates, Caldwell, Carroll, Cass, Chariton, Clay and 15 more | 9 hr |
| Feb 27, 2:12 PM CST | Mesoscale Discussion | SPC | Barton, Dade, Jasper, Lawrence, Newton | 93 min |
| Feb 27, 3:24 PM CST | Mesoscale Discussion | SPC | Bates, Carroll, Cass, Chariton, Clay, Cooper and 10 more | 66 min |
Nearby
Mesoscale Discussions in Iowa, 2011Mesoscale Discussions in Illinois, 2011Mesoscale Discussions in Missouri, 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.