Alert archive / Nebraska / Mesoscale Discussions in 2012
Mesoscale Discussion 679
The Storm Prediction Center issued this mesoscale discussion at May 3, 2012, 3:41 PM CDT for 4 states. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- May 3, 2012, 3:41 PM CDT (20:41 UTC)
- Expired
- May 3, 2012, 5:45 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 60%
All 51 counties
Adair County, IA, Adams County, IA, Cass County, IA, Clarke County, IA, Fremont County, IA, Madison County, IA, Mills County, IA, Montgomery County, IA, Page County, IA, Pottawattamie County, IA, Ringgold County, IA, Taylor County, IA, Union County, IA, Jewell County, KS, Marshall County, KS, Phillips County, KS, Republic County, KS, Smith County, KS, Washington County, KS, Atchison County, MO, Holt County, MO, Nodaway County, MO, Worth County, MO, Adams County, NE, Butler County, NE, Cass County, NE, Clay County, NE, Douglas County, NE, Fillmore County, NE, Franklin County, NE, Gage County, NE, Hall County, NE, Hamilton County, NE, Harlan County, NE, Jefferson County, NE, Johnson County, NE, Kearney County, NE, Lancaster County, NE, Nemaha County, NE, Nuckolls County, NE, Otoe County, NE, Pawnee County, NE, Phelps County, NE, Richardson County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Thayer County, NE, Webster County, NE, York County, NE
The radar
The Omaha radar (KOAX), 114 km from the middle of the area, began a volume at 20:41 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, 8.7 hours before the alert went out and 114 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
- 497 J/kg
- Mixed-layer CIN
- -269 J/kg
- Mixed-layer LCL
- 1132 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 75 m²/s²
- 0-3 km storm-relative helicity
- 15 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.6
The text
As transmitted, in the capitals the NWS used until 2016.
601
ACUS11 KWNS 032041
SWOMCD
SPC MCD 032041
IAZ000-MOZ000-NEZ000-KSZ000-032245-
MESOSCALE DISCUSSION 0679
NWS STORM PREDICTION CENTER NORMAN OK
0341 PM CDT THU MAY 03 2012
AREAS AFFECTED...SERN NEB...FAR N-CNTRL KS...SWRN IA
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 032041Z - 032245Z
PROBABILITY OF WATCH ISSUANCE...60 PERCENT
SUMMARY...INCREASING POTENTIAL FOR SEVERE THUNDERSTORMS ACROSS SERN
NEB...FAR N-CNTRL KS AND SWRN IA. WW MAY BE NEEDED FOR PORTIONS OF
THIS AREA IN THE NEXT 1 TO 2 HOURS.
DISCUSSION...SURFACE OBJECTIVE ANALYSIS INDICATES SURFACE-BASED CINH
HAS ERODED ALONG A CORRIDOR FROM N-CNTRL KS NEWD INTO SWRN IA INVOF
A WEAK PRE-FRONTAL TROUGH. TEMPERATURES IN THE 80S AND DEWPOINTS IN
THE UPPER 60S TO LOW 70S BELOW STEEP MID-LEVEL LAPSE RATES HAVE
RESULTED IN A VERY UNSTABLE AIR MASS /SBCAPE VALUES AOA 3000 J/KG /
ACROSS THE AREA. INCREASING THUNDERSTORM COVERAGE IS ANTICIPATED AS
THE PREVIOUSLY MENTIONED PRE-FRONTAL TROUGH PROGRESSES SLOWLY SEWD.
ELY/ESELY STORM MOTION WILL TAKE ANY STORMS THAT DEVELOP INTO A MORE
UNSTABLE ENVIRONMENT WITH BULK SHEAR FORECAST TO INCREASE. FORECAST
GUIDANCE SUGGESTS THE POTENTIAL FOR GREATER STORM COVERAGE E WITHIN
THE INSTABILITY AXIS INTO THE EVENING. STORMS IN THIS ENVIRONMENT
WILL POSE A THREAT OF LARGE HAIL/DAMAGING WINDS AND A WATCH MAY BE
NEEDED.
..MOSIER/BUNTING/CARBIN.. 05/03/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...DMX...EAX...OAX...TOP...GID...GLD...
LAT...LON 40119512 39679691 39489828 39409880 39399925 39519972
40039983 40389972 40579940 40779889 41309693 41519543
41579448 41529394 41249360 40569399 40119512SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 2, 10:43 PM CDT | Mesoscale Discussion | SPC | Harrison, Monona, Plymouth, Sioux, Woodbury | 62 min |
| May 3, 12:50 AM CDT | Severe Thunderstorm Watch | SPC | Adams, Cass, Fremont, Mills, Montgomery, Page and 2 more | 4 hr |
| May 3, 3:05 AM CDT | Mesoscale Discussion | SPC | Adair, Adams, Cass, Clarke, Decatur, Montgomery and 4 more | 85 min |
| May 3, 2:12 PM CDT | Mesoscale Discussion | SPC | Buena Vista, Calhoun, Cerro Gordo, Cherokee, Clay, Dickinson and 18 more | 2 hr |
| May 3, 6:42 PM CDT | Mesoscale Discussion | SPC | Appanoose, Davis, Decatur, Des Moines, Henry, Lee and 5 more | 63 min |
| May 2, 7:32 PM CDT | Severe Thunderstorm Watch | SPC | Graham, Jewell, Mitchell, Norton, Osborne, Phillips and 2 more | 6 hr |
Nearby
Mesoscale Discussions in Nebraska, 2012Mesoscale Discussions in Iowa, 2012Mesoscale Discussions in Kansas, 2012Every mesoscale discussion in 2012
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.