Alert archive / Nebraska / Mesoscale Discussions in 2003

Mesoscale Discussion 2248

August 25, 200317 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Aug 25, 2003, 3:44 PM CDT for 17 counties in Nebraska. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Aug 25, 2003, 3:44 PM CDT (20:44 UTC)
Expired
Aug 25, 2003, 5:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center

Counties Antelope County, NE, Boone County, NE, Custer County, NE, Dawson County, NE, Frontier County, NE, Garfield County, NE, Greeley County, NE, Hayes County, NE, Lincoln County, NE, Logan County, NE, Loup County, NE, Madison County, NE, Pierce County, NE, Stanton County, NE, Valley County, NE, Wayne County, NE, Wheeler County, NE

The radar

The North Platte radar (KLNX), 115 km from the middle of the area, began a volume at 20:45 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 12:00Z, 8.7 hours before the alert went out and 111 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 12:00Z on 2003-08-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2003-08-25The 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2502 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
5 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.

834 
ACUS11 KWNS 252045
SWOMCD
SPC MCD 252044 
NEZ000-252245-

MESOSCALE DISCUSSION 2248
NWS STORM PREDICTION CENTER NORMAN OK
0344 PM CDT MON AUG 25 2003

AREAS AFFECTED...CNTRL/NE NEB

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 252044Z - 252245Z

ISOLATED DOWNBURSTS...PERHAPS SOME HAIL...MAY ACCOMPANY STRONGEST
CELLS THROUGH EARLY EVENING.  HOWEVER...WW IS NOT CURRENTLY
ANTICIPATED.

LATEST VISIBLE IMAGERY INDICATES DEEPENING CONVECTIVE DEVELOPMENT
ALONG WEAK SURFACE BOUNDARY ACROSS CENTRAL NEBRASKA.  WIND SHIFT
EXTENDS FROM AREAS SOUTHEAST OF IMPERIAL INTO THE VICINITY OF BROKEN
BOW...EAST NORTHEASTWARD INTO AREAS NORTHWEST OF SIOUX CITY IA. 
STRONG HEATING TO AROUND 100F HAS CONTRIBUTED TO A DEEP MIXED
BOUNDARY LAYER WITH CAPE IN EXCESS OF 1000 J/KG ALONG/JUST SOUTH OF
BOUNDARY...SUPPORTIVE OF VIGOROUS UPDRAFTS.  ACTIVITY MAY CONTINUE
TO INCREASE/INTENSIFY LATE THIS AFTERNOON...AIDED BY WEAK
LARGE-SCALE FORCING FOR UPWARD VERTICAL MOTION ASSOCIATED WITH
APPROACHING SHORT WAVE TROUGH. LOW AMPLITUDE TROUGH IS EMBEDDED
WITHIN WEAK SUBTROPICAL JET...AND PROGGED TO ONLY SLOWLY MIGRATE
EASTWARD OUT OF THE NORTH CENTRAL HIGH PLAINS LATE THIS AFTERNOON
AND EVENING.  WHILE THERMODYNAMIC ENVIRONMENT IS SUPPORTIVE OF LARGE
HAIL...THIS THREAT WILL BE MARGINALIZED BY WEAK ENVIRONMENTAL SHEAR.
 ISOLATED DAMAGING DOWNBURSTS APPEARS PRIMARY SEVERE THREAT...AS
LARGE TEMPERATURE/ DEW POINT SPREADS IN THE SUB CLOUD LAYER ENHANCES
EVAPORATIVE COOLING IN DOWNDRAFTS.

..KERR.. 08/25/2003

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

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

41640040 42349910 42649751 42399670 41619739 41359883
40829947 40250050 40370143 41100112

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 25, 6:21 PM CDTMesoscale DiscussionSPCKeya Paha54 min

Nearby

Mesoscale Discussions in Nebraska, 2003Every mesoscale discussion in 2003

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.