Alert archive / Nebraska / Mesoscale Discussions in 2012
Mesoscale Discussion 1689
The Storm Prediction Center issued this mesoscale discussion at Aug 3, 2012, 1:02 AM CDT for Boyd County, Keya Paha County, Nebraska; Gregory County, South Dakota. It was in force for 88 min.
The area
The outline as issued.
The facts
- Issued
- Aug 3, 2012, 1:02 AM CDT (06:02 UTC)
- Expired
- Aug 3, 2012, 2:30 AM CDT
- In force
- 88 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
Counties Boyd County, NE, Keya Paha County, NE, Gregory County, SD
The radar
The North Platte radar (KLNX), 168 km from the middle of the area, began a volume at 06:03 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
Aberdeen, SD (KABR), launched 00:00Z, 6.0 hours before the alert went out and 219 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
- 163 J/kg
- Mixed-layer CIN
- -119 J/kg
- Mixed-layer LCL
- 2218 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 25 m²/s²
- 0-3 km storm-relative helicity
- 101 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted, in the capitals the NWS used until 2016.
580 ACUS11 KWNS 030602 SWOMCD SPC MCD 030602 NEZ000-SDZ000-030730- MESOSCALE DISCUSSION 1689 NWS STORM PREDICTION CENTER NORMAN OK 0102 AM CDT FRI AUG 03 2012 AREAS AFFECTED...EXTREME SCNTRL SD INTO NERN NEB CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 030602Z - 030730Z PROBABILITY OF WATCH ISSUANCE...20 PERCENT SUMMARY...STORMS MAY CONTINUE TO POSE A THREAT FOR ISOLATED LARGE HAIL AND DAMAGING WIND THROUGH 08Z AS THEY CONTINUE ESEWD THROUGH SCNTRL SD INTO EXTREME NERN NEB. SPATIAL EXTENT AND DURATION OF THREAT WILL PROBABLY NOT WARRANT A WW. HOWEVER...IF STORMS BEGIN TO SHOW SIGNS OF INCREASING IN AREAL COVERAGE...A SEVERE THUNDERSTORM WATCH MIGHT NEED TO BE CONSIDERED. DISCUSSION...SEVERE STORM ALONG THE SD-NEB BORDER IN TRIPP COUNTY IS MOVING ESE AT AROUND 35 KT. CONVECTIVE INHIBITION REMAINS STRONG WITH RESPECT TO SFC BASED PARCELS...AND LESS SO FOR PARCELS LIFTED FROM ABOVE THE SFC LAYER. THE STORM APPEARS TO BE FORWARD PROPAGATING ALONG ITS CONVECTIVE OUTFLOW BOUNDARY WITH CONVERGENCE AND MESOSCALE ASCENT AUGMENTED BY 30 KT SLY LLJ. STORMS ARE EXPECTED TO CONTINUE ESEWD ALONG INSTABILITY GRADIENT NEXT COUPLE HOURS...HOWEVER SOME WEAKENING MIGHT EVENTUALLY OCCUR AS ACTIVITY SHIFTS FARTHER AWAY FROM THE LLJ AXIS. ..DIAL/WEISS.. 08/03/2012 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...FSD...OAX...LBF...UNR... LAT...LON 43309977 43159790 42329796 42879999 43309977
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 3, 6:19 PM CDT | Mesoscale Discussion | SPC | Antelope, Blaine, Boyd, Brown, Cedar, Cherry and 9 more | 86 min |
| Aug 2, 7:10 PM CDT | Mesoscale Discussion | SPC | Butte, Harding, Lawrence, Meade, Perkins | 95 min |
| Aug 3, 1:31 PM CDT | Mesoscale Discussion | SPC | Brown, Campbell, Dewey, Edmunds, Faulk, Haakon and 10 more | 59 min |
| Aug 3, 2:14 PM CDT | Severe Thunderstorm Watch | SPC | Aurora, Beadle, Bon Homme, Brookings, Brown, Brule and 34 more | 7 hr |
Nearby
Mesoscale Discussions in Nebraska, 2012Mesoscale Discussions in South Dakota, 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.