Alert archive / Nebraska / Mesoscale Discussions in 2010

Mesoscale Discussion 1421

July 22, 2010Box Butte County, Dawes County, Sheridan County, Nebraska; Bennett County, Oglala Lakota County, South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 22, 2010, 5:35 PM MDT for Box Butte County, Dawes County, Sheridan County, Nebraska; Bennett County, Oglala Lakota County, South Dakota. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued
Jul 22, 2010, 5:35 PM MDT (23:35 UTC)
Expired
Jul 22, 2010, 7:00 PM MDT
In force
85 min
Issued by
the Storm Prediction Center

Counties Box Butte County, NE, Dawes County, NE, Sheridan County, NE, Bennett County, SD, Oglala Lakota County, SD

The radar

The Rapid City radar (KUDX), 146 km from the middle of the area, began a volume at 23:38 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

Rapid City, SD (KUNR), launched 12:00Z, 11.6 hours before the alert went out and 140 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-pSkew-T log-p diagram, Rapid City, SD at 12:00Z on 2010-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 34 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Rapid City, SD at 12:00Z on 2010-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -39 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
34 J/kg
Mixed-layer CIN
-350 J/kg
Mixed-layer LCL
860 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
-39 m²/s²
0-3 km storm-relative helicity
18 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.

470 
ACUS11 KWNS 222335
SWOMCD
SPC MCD 222335 
NEZ000-SDZ000-230100-

MESOSCALE DISCUSSION 1421
NWS STORM PREDICTION CENTER NORMAN OK
0635 PM CDT THU JUL 22 2010

AREAS AFFECTED...NEB PANHANDLE/SOUTHWEST SD

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 222335Z - 230100Z

A CORRIDOR OF DAMAGING WIND/SEVERE HAIL POTENTIAL WILL
EXIST/CONTINUE THROUGH THE EARLY EVENING HOURS ACROSS THE NORTHERN
NEB PANHANDLE/SOUTHWEST SD. A WATCH IS NOT CURRENTLY EXPECTED.

A SMALL QUASI-LINEAR/FORWARD PROPAGATION EAST-SOUTHEASTWARD MOVING
CLUSTER...CURRENTLY OVER FALL RIVER COUNTY SD AS OF 2320Z...SHOULD
CONTINUE TO STEADILY PROGRESS EAST-SOUTHEASTWARD...WHILE POTENTIALLY
CONTINUING TO EXPAND/ACCELERATE AND MERGE WITH ADDITIONAL
SEMI-DISCRETE STORMS CURRENTLY OVER DAWES/BOX BUTTE COUNTIES NEB.
WITHIN A WEAK LOW LEVEL UPSLOPE REGIME...THIS ACTIVITY APPEARS TO BE
AIDED BY A PASSING MID LEVEL SPEED MAX /50+ KT/ PER CYS/UDX WSR-88D
VWP DATA. IN ALL...EXISTING STORM-SCALE ORGANIZATION AND FAVORABLE
BACKGROUND VERTICAL SHEAR...IN CONJUNCTION WITH A SUFFICIENTLY
MOIST/UNSTABLE DOWNSTREAM AIRMASS...WILL LIKELY MAINTAIN/PERHAPS
SOMEWHAT INCREASE THE DAMAGING WIND/SEVERE HAIL POTENTIAL ACROSS THE
NORTHERN NEB PANHANDLE /INCLUDING CHADRON VICINITY/ AND FAR
SOUTHWEST SD OVER THE NEXT HOUR OR TWO.

..GUYER.. 07/22/2010

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

ATTN...WFO...LBF...UNR...CYS...

LAT...LON   43130360 43600286 43280158 42130170 42070304 42330351
            43130360

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 21, 6:22 PM MDTMesoscale DiscussionSPCArthur, Banner, Blaine, Box Butte, Boyd, Brown and 27 more83 min
Jul 21, 7:21 PM MDTMesoscale DiscussionSPCBoyd, Cedar, Dakota, Dixon, Knox, Thurston54 min
Jul 21, 9:09 PM MDTMesoscale DiscussionSPCBrown, Cherry, Grant, Hooker, Keya Paha, Sheridan and 1 more96 min
Jul 21, 9:55 PM MDTMesoscale DiscussionSPCChase, Dawson, Dundy, Frontier, Furnas, Gosper and 4 more65 min
Jul 21, 10:40 PM MDTMesoscale DiscussionSPCBoyd, Cedar, Dixon, Holt, Knox2 hr
Jul 22, 1:06 PM MDTMesoscale DiscussionSPCAntelope, Boone, Burt, Butler, Cedar, Colfax and 19 more114 min
Jul 22, 3:31 PM MDTMesoscale DiscussionSPCFurnas, Harlan, Hitchcock, Red Willow89 min

Nearby

Mesoscale Discussions in Nebraska, 2010Mesoscale Discussions in South Dakota, 2010Every mesoscale discussion in 2010

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.