Alert archive / Nebraska / Mesoscale Discussions in 2013

Mesoscale Discussion 813

May 26, 201330 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at May 26, 2013, 9:07 PM CDT for 30 counties in Nebraska. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued
May 26, 2013, 9:07 PM CDT (02:07 UTC)
Expired
May 26, 2013, 10:30 PM CDT
In force
83 min
Issued by
the Storm Prediction Center
All 30 counties

Antelope County, NE, Blaine County, NE, Boone County, NE, Brown County, NE, Butler County, NE, Cedar County, NE, Colfax County, NE, Cuming County, NE, Custer County, NE, Dakota County, NE, Dixon County, NE, Garfield County, NE, Greeley County, NE, Holt County, NE, Howard County, NE, Knox County, NE, Loup County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Pierce County, NE, Platte County, NE, Polk County, NE, Rock County, NE, Sherman County, NE, Stanton County, NE, Thurston County, NE, Valley County, NE, Wayne County, NE, Wheeler County, NE

The radar

The North Platte radar (KLNX), 172 km from the middle of the area, began a volume at 02:09 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

Omaha, NE (KOAX), launched 00:00Z, 2.1 hours before the alert went out and 190 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, Omaha, NE at 00:00Z on 2013-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3377 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, Omaha, NE at 00:00Z on 2013-05-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 151 square meters per square second.1939Sfc1 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
3377 J/kg
Mixed-layer CIN
-26 J/kg
Mixed-layer LCL
966 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
151 m²/s²
0-3 km storm-relative helicity
272 m²/s²
Significant tornado parameter
3.3
Supercell composite
16.4

Open this sounding in Storm Lab

The text

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

410 
ACUS11 KWNS 270208
SWOMCD
SPC MCD 270207 
IAZ000-NEZ000-SDZ000-270330-

MESOSCALE DISCUSSION 0813
NWS STORM PREDICTION CENTER NORMAN OK
0907 PM CDT SUN MAY 26 2013

AREAS AFFECTED...CNTRL/ERN/NRN NEB

CONCERNING...TORNADO WATCH 223...

VALID 270207Z - 270330Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 223 CONTINUES.

SUMMARY...ALL HAZARD THREATS CONTINUE NEAR-TERM WITH SUPERCELLS JUST
N OF THE QUASI-STATIONARY FRONT. ADDITIONAL /PRIMARILY ELEVATED/
TSTMS SHOULD DEVELOP EWD INTO NERN NEB WITH MAIN THREAT BEING LARGE
HAIL. DOWNSTREAM SEVERE TSTM WATCH ISSUANCE IS POSSIBLE WITHIN THE
NEXT 1-2 HOURS.

DISCUSSION...02Z SURFACE ANALYSIS PLACED A QUASI-STATIONARY FRONT
FROM 20 S BBW TO NEAR SDA. ALL SEVERE HAZARDS REMAIN POSSIBLE
NEAR-TERM WITH SUPERCELLS JUST N OF THIS FRONT...BUT A GRADUALLY
COOLING BOUNDARY LAYER AND UPSCALE GROWTH SHOULD YIELD A SLOWLY
DIMINISHING TORNADO THREAT. LLJ HAS STRENGTHENED TO 40 KT PER KUEX
VWP DATA. THIS WILL MAINTAIN CONTINUED ISENTROPIC ASCENT N OF THE
FRONT AND INFLOW OF A STRONGLY BUOYANT AIR MASS. ELEVATED CONVECTION
HAS BLOSSOMED IN THE PAST HALF HOUR IN N-CNTRL NEB /WHERE SURFACE
TEMPERATURES ARE IN THE 60S/. THIS ACTIVITY SHOULD MAINLY POSE A
THREAT FOR SEVERE HAIL AS IT DEVELOPS INTO NERN NEB.

..GRAMS.. 05/27/2013

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

ATTN...WFO...FSD...OAX...GID...LBF...

LAT...LON   41640037 42340026 42649900 42659812 42719703 42429635
            42029636 41169702 41039852 41070009 41640037

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 26, 7:33 PM CDTTornado WatchSPCAntelope, Blaine, Boone, Brown, Buffalo, Custer and 18 more4 hr
May 26, 11:03 PM CDTSevere Thunderstorm WatchSPCAntelope, Blaine, Boone, Burt, Butler, Cass and 37 more6 hr
May 27, 1:40 AM CDTMesoscale DiscussionSPCBurt, Cass, Douglas, Nemaha, Otoe, Richardson and 3 more95 min
May 27, 2:00 PM CDTMesoscale DiscussionSPCArthur, Banner, Blaine, Box Butte, Brown, Chase and 27 more60 min
May 27, 2:19 PM CDTSevere Thunderstorm WatchSPCArthur, Banner, Box Butte, Chase, Cheyenne, Dawes and 13 more6 hr
May 27, 3:23 PM CDTMesoscale DiscussionSPCFranklin, Furnas, Harlan, Nuckolls, Webster67 min
May 27, 4:49 PM CDTTornado WatchSPCAdams, Buffalo, Clay, Dawson, Fillmore, Franklin and 22 more7 hr
May 27, 5:41 PM CDTMesoscale DiscussionSPCArthur, Box Butte, Chase, Cheyenne, Dawes, Deuel and 7 more94 min
May 27, 6:53 PM CDTMesoscale DiscussionSPCAdams, Buffalo, Clay, Dawson, Fillmore, Franklin and 17 more2 hr

Nearby

Mesoscale Discussions in Nebraska, 2013Every mesoscale discussion in 2013

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.