Alert archive / Nebraska / Mesoscale Discussions in 2011
Mesoscale Discussion 1902
The Storm Prediction Center issued this mesoscale discussion at Aug 8, 2011, 2:09 PM MDT for 17 counties in Nebraska; Custer County, Fall River County, South Dakota. It was in force for 66 min.
The area
The outline as issued.
The facts
- Issued
- Aug 8, 2011, 2:09 PM MDT (20:09 UTC)
- Expired
- Aug 8, 2011, 3:15 PM MDT
- In force
- 66 min
- Issued by
- the Storm Prediction Center
Counties Arthur County, NE, Blaine County, NE, Box Butte County, NE, Custer County, NE, Dawes County, NE, Garden County, NE, Grant County, NE, Hooker County, NE, Keith County, NE, Lincoln County, NE, Logan County, NE, McPherson County, NE, Morrill County, NE, Scotts Bluff County, NE, Sheridan County, NE, Sioux County, NE, Thomas County, NE, Custer County, SD, Fall River County, SD
The radar
The North Platte radar (KLNX), 113 km from the middle of the area, began a volume at 20:09 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
N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 8.2 hours before the alert went out and 154 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
- 426 J/kg
- Mixed-layer CIN
- -479 J/kg
- Mixed-layer LCL
- 1363 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 34 m²/s²
- 0-3 km storm-relative helicity
- 133 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted, in the capitals the NWS used until 2016.
015
ACUS11 KWNS 082010
SWOMCD
SPC MCD 082009
NEZ000-SDZ000-WYZ000-082115-
MESOSCALE DISCUSSION 1902
NWS STORM PREDICTION CENTER NORMAN OK
0309 PM CDT MON AUG 08 2011
AREAS AFFECTED...WRN SD/NEB...CNTRL NEB
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 082009Z - 082115Z
INITIATION OF STORMS REMAINS UNCERTAIN...WITH SOME MODEL SUGGESTION
OF MORE ROBUST STORMS OCCURRING IN THE NEXT HOUR OR TWO. SHOULD
STRONGER CONVECTION OCCUR...DMGG WINDS AND HAIL WILL BECOME
POSSIBLE...AND THE AREA MAY BE CONSIDERED FOR A WW.
CONVECTIVE INHIBITION CONTINUES TO GRADUALLY ERODE AMIDST AMPLE
SURFACE HEATING. MODEL CONSENSUS GENERALLY WOULD SUPPORT INITIAL
DEVELOPMENT ALONG THE MOISTURE GRADIENT IN WRN SD/NEB...AND ALONG A
REMNANT W-E ORIENTED OUTFLOW BOUNDARY IN CNTRL NEB...OBSERVED ON 20Z
VISIBLE IMAGERY NEAR LBF. ALTHOUGH THUNDERSTORMS ARE ONGOING ACROSS
THE BLACK HILLS...CONVECTIVE INITIATION REMAINS SOMEWHAT UNCERTAIN
ACROSS THE REMAINDER OF THE MCD AREA. MODEL CONSENSUS IS GENERALLY
TOO FAST IN INITIATING CONVECTION...THOUGH RECENT HI-RES SUGGESTS
STRONGER UPDRAFTS MAY BE POSSIBLE IN THE NEXT HOUR OR TWO. WEAK
UPPER SUPPORT IN ASSOCIATION WITH A VORT MAX ACROSS WRN SD/NEB AND
ANOTHER NEAR THE N CNTRL NEB/S CNTRL SD AROUND THE BASE OF A COMPACT
UPPER LOW IN SRN MANITOBA MAY INFLUENCE INITIAL DEVELOPMENT ALONG
WEAK SURFACE CONVERGENCE...BUT GIVEN THE WEAK NATURE OF THE
UPPER/SURFACE FEATURES...OVERALL COVERAGE OF STORMS MAY BE LIMITED.
HOWEVER...SHOULD DEVELOPMENT OF HIGH-BASED THUNDERSTORMS
OCCUR...MODEST WLY FLOW AND THE PRESENCE OF MODERATE INSTABILITY
ACROSS WRN/CNTRL NEB SUGGEST THAT SEMI-ORGANIZED MULTICELLULAR
CLUSTERS AND SUPERCELLS MAY CONTINUE EWD...PRODUCING HAIL AND DMGG
WINDS.
..HURLBUT.. 08/08/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...GID...LBF...UNR...CYS...
LAT...LON 41209939 40680026 40950155 41240238 41620347 42300419
42950424 43710383 43760316 42700176 42520112 42430029
41209939SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 7, 6:49 PM MDT | Severe Thunderstorm Watch | SPC | Adams, Antelope, Blaine, Boone, Boyd, Brown and 60 more | 7 hr |
| Aug 7, 9:28 PM MDT | Mesoscale Discussion | SPC | Antelope, Boone, Burt, Butler, Cass, Cedar and 30 more | 2 hr |
| Aug 8, 1:41 AM MDT | Mesoscale Discussion | SPC | Adams, Buffalo, Butler, Cass, Clay, Fillmore and 23 more | 34 min |
| Aug 8, 3:52 PM MDT | Severe Thunderstorm Watch | SPC | Arthur, Box Butte, Chase, Cherry, Cheyenne, Dawes and 19 more | 6 hr |
| Aug 8, 5:27 PM MDT | Mesoscale Discussion | SPC | Arthur, Box Butte, Chase, Cheyenne, Dawes, Dawson and 21 more | 2 hr |
| Aug 8, 5:44 PM MDT | Severe Thunderstorm Watch | SPC | Dawson, Furnas, Gosper, Harlan, Phelps | 4 hr |
Nearby
Mesoscale Discussions in Nebraska, 2011Mesoscale Discussions in South Dakota, 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.