Alert archive / Nebraska / Mesoscale Discussions in 2005

Mesoscale Discussion 751

May 6, 200520 counties in Nebraska; Bennett County, Todd County, South Dakota

The Storm Prediction Center issued this mesoscale discussion at May 6, 2005, 7:56 PM MDT for 20 counties in Nebraska; Bennett County, Todd County, South Dakota. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued
May 6, 2005, 7:56 PM MDT (01:56 UTC)
Expired
May 6, 2005, 9:30 PM MDT
In force
94 min
Issued by
the Storm Prediction Center
All 22 counties

Arthur County, NE, Blaine County, NE, Brown County, NE, Buffalo County, NE, Cherry County, NE, Custer County, NE, Dawson County, NE, Garfield County, NE, Grant County, NE, Greeley County, NE, Hooker County, NE, Keya Paha County, NE, Lincoln County, NE, Logan County, NE, Loup County, NE, McPherson County, NE, Rock County, NE, Sherman County, NE, Thomas County, NE, Valley County, NE, Bennett County, SD, Todd County, SD

The radar

The North Platte radar (KLNX), 10 km from the middle of the area, began a volume at 02:00 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

N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 1.9 hours before the alert went out and 102 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, N. Platte/Lee Bi, NE at 00:00Z on 2005-05-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1660 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, N. Platte/Lee Bi, NE at 00:00Z on 2005-05-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 89 square meters per square second.193958Sfc1 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
1660 J/kg
Mixed-layer CIN
-39 J/kg
Mixed-layer LCL
1882 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
89 m²/s²
0-3 km storm-relative helicity
124 m²/s²
Significant tornado parameter
0.1
Supercell composite
2.8

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 070156
SWOMCD
SPC MCD 070156 
NEZ000-SDZ000-070330-

MESOSCALE DISCUSSION 0751
NWS STORM PREDICTION CENTER NORMAN OK
0856 PM CDT FRI MAY 06 2005

AREAS AFFECTED...NEB...SD...ERN CO...WRN KS

CONCERNING...SEVERE THUNDERSTORM WATCH 222...

VALID 070156Z - 070330Z

CURRENT INDICATIONS ARE WW MAY BE ALLOWED TO EXPIRE AS SCHEDULED AT
03Z.

CONVECTION CONTINUES TO SLOWLY CONGEAL/CONSOLIDATE IN THE VICINITY
OF LEE SURFACE TROUGH ACROSS THE NORTH CENTRAL HIGH PLAINS. BOUNDARY
LAYER COOLING IS ONGOING...AND ACTIVITY MOST LIKELY IS ALREADY BASED
ABOVE NEAR SURFACE INVERSION LAYER.  FORCING FOR CONVECTIVE
DEVELOPMENT INTO THE OVERNIGHT HOURS IS SOMEWHAT UNCERTAIN...BUT
WARM ADVECTION/CONVERGENCE ON NOSE OF SOUTHERLY LOW-LEVEL JET MAY
PROVIDE SUPPORT FOR PRIMARY NEW DEVELOPMENT THROUGH THE 03-06Z TIME
FRAME. THIS APPEARS TO BE IN PROCESS OF BECOMING FOCUSED ACROSS
NORTH CENTRAL NEBRASKA...BETWEEN BROKEN BOW AND VALENTINE...BEFORE
LOW-LEVEL JET AXIS CONTINUES TO VEER TO A MORE SOUTHWESTERLY
COMPONENT OVERNIGHT.

WEAK FLOW WITHIN MID/UPPER RIDGE ACROSS THIS REGION WILL MINIMIZE
SHEAR...BUT THERMODYNAMIC ENVIRONMENT MAY REMAIN FAVORABLE FOR
OCCASIONAL LARGE HAIL IN STRONGER STORMS.

..KERR.. 05/07/2005

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

ATTN...WFO...GID...LBF...UNR...

42990250 43440075 42649886 41329843 40599940 40870051
41560175

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 7, 11:23 AM MDTMesoscale DiscussionSPCBlaine, Boyd, Brown, Cherry, Custer, Dawson and 13 more3 hr
May 7, 12:15 PM MDTMesoscale DiscussionSPCFranklin, Frontier, Furnas, Gosper, Harlan, Kearney and 3 more3 hr
May 7, 12:50 PM MDTSevere Thunderstorm WatchSPCAdams, Blaine, Boyd, Brown, Buffalo, Cherry and 29 more7 hr
May 7, 4:02 PM MDTMesoscale DiscussionSPCBurt, Butler, Cass, Cedar, Colfax, Cuming and 19 more118 min
May 7, 4:32 PM MDTMesoscale DiscussionSPCAdams, Antelope, Boone, Boyd, Buffalo, Butler and 36 more118 min
May 6, 10:36 PM MDTMesoscale DiscussionSPCLincoln, Minnehaha54 min
May 7, 2:25 PM MDTMesoscale DiscussionSPCBrown, Campbell, Corson, Dewey, Edmunds, Faulk and 4 more2 hr
May 7, 3:40 PM MDTSevere Thunderstorm WatchSPCCampbell, Corson, Dewey, Edmunds, Faulk, Hand and 5 more5 hr
May 7, 5:47 PM MDTMesoscale DiscussionSPCBrown, Campbell, Edmunds, Faulk, McPherson, Walworth118 min

Nearby

Mesoscale Discussions in Nebraska, 2005Mesoscale Discussions in South Dakota, 2005Every mesoscale discussion in 2005

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.