Alert archive / South Dakota / Mesoscale Discussions in 2011

Mesoscale Discussion 2102

September 3, 2011Boyd County, Cherry County, Keya Paha County, Nebraska; 5 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Sep 3, 2011, 1:20 AM CDT for Boyd County, Cherry County, Keya Paha County, Nebraska; 5 counties in South Dakota. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued: Sep 3, 2011, 1:20 AM CDT (06:20 UTC)
Expired: Sep 3, 2011, 2:45 AM CDT
In force: 85 min
Issued by: the Storm Prediction Center

Counties Boyd County, NE, Cherry County, NE, Keya Paha County, NE, Brule County, SD, Charles Mix County, SD, Gregory County, SD, Todd County, SD, Tripp County, SD

The radar

The North Platte radar (KLNX), 145 km from the middle of the area, began a volume at 06:23 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, 6.3 hours before the alert went out and 233 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1494 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 81 m²/s²
0-3 km storm-relative helicity: 147 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

954 
ACUS11 KWNS 030620
SWOMCD
SPC MCD 030620 
SDZ000-NEZ000-030745-

MESOSCALE DISCUSSION 2102
NWS STORM PREDICTION CENTER NORMAN OK
0120 AM CDT SAT SEP 03 2011

AREAS AFFECTED...SCNTRL THROUGH SERN SD AND EXTREME NRN NEB

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 030620Z - 030745Z

STORMS MAY CONTINUE TO POSE A THREAT FOR ISOLATED DAMAGING WIND AND
HAIL AS THEY DEVELOP SEWD THROUGH SRN SD AND POSSIBLY INTO EXTREME
NRN NEB NEXT 2-3 HOURS. CONVECTIVE TRENDS ARE BEING MONITORED FOR A
POSSIBLE WW.

A COLD FRONT PARTIALLY REINFORCED BY ONGOING CONVECTION IS SURGING
SEWD THROUGH SWRN SD WITH NRN END EXTENDING THROUGH N-CNTRL SD AND
INTO ND. THIS BOUNDARY WILL ADVANCE EWD AND SEWD THROUGH THE MORNING
IN ASSOCIATION WITH PROGRESSIVE SHORTWAVE TROUGH MOVING THROUGH THE
NRN PLAINS. LATEST OBJECTIVE ANALYSIS DATA INDICATE A RESERVOIR OF
MODERATE MUCAPE ABOVE A STABLE SURFACE LAYER ACROSS CNTRL AND SRN SD
INTO NRN NEB...AND THIS REGION ALSO LIES ALONG NRN FRINGE OF STEEPER
MID LEVEL LAPSE RATE PLUME. FORCING ALONG THE SEWD SURGING FRONT AND
INFLUENCE OF DEEPER ASCENT FROM THE PROGRESSIVE SHORTWAVE TROUGH
WILL PROBABLY BE SUFFICIENT TO MAINTAIN STORMS NEXT SEVERAL HOURS
THROUGH SRN SD INTO NRN NEB. STORMS ARE EMBEDDED WITHIN 40-50 KT
EFFECTIVE SHEAR SUFFICIENT FOR ORGANIZED STRUCTURES WITH ISOLATED
LARGE HAIL AND DAMAGING WIND POSSIBLE.

..DIAL.. 09/03/2011

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...FSD...ABR...LBF...UNR...

LAT...LON   43460105 43849996 43839887 43269835 42589905 42480116
            42880163 43460105

Nearby

Mesoscale Discussions in South Dakota, 2011 Mesoscale Discussions in Nebraska, 2011 Every 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.