Alert archive / Nebraska / Mesoscale Discussions in 2004

Mesoscale Discussion 2349

October 22, 20047 counties in Iowa; 8 counties in Kansas; 22 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Oct 22, 2004, 10:29 AM CDT for 7 counties in Iowa; 8 counties in Kansas; 22 counties in Nebraska. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Oct 22, 2004, 10:29 AM CDT (15:29 UTC)
Expired: Oct 22, 2004, 12:30 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 37 counties

Crawford County, IA, Fremont County, IA, Harrison County, IA, Mills County, IA, Monona County, IA, Pottawattamie County, IA, Shelby County, IA, Clay County, KS, Cloud County, KS, Dickinson County, KS, Marshall County, KS, Ottawa County, KS, Republic County, KS, Riley County, KS, Washington County, KS, Burt County, NE, Butler County, NE, Cass County, NE, Colfax County, NE, Dodge County, NE, Douglas County, NE, Fillmore County, NE, Gage County, NE, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Polk County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Thayer County, NE, Washington County, NE, York County, NE

The radar

The Omaha radar (KOAX), 109 km from the middle of the area, began a volume at 15:31 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

Omaha, NE (KOAX), launched 12:00Z, 3.5 hours before the alert went out and 109 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: 773 J/kg
Mixed-layer CIN: -308 J/kg
Mixed-layer LCL: 881 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 151 m²/s²
0-3 km storm-relative helicity: 150 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

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

713 
ACUS11 KWNS 221529
SWOMCD
SPC MCD 221529 
IAZ000-MOZ000-NEZ000-KSZ000-221730-

MESOSCALE DISCUSSION 2349
NWS STORM PREDICTION CENTER NORMAN OK
1029 AM CDT FRI OCT 22 2004

AREAS AFFECTED...PORTIONS N-CENTRAL/NERN KS...SERN AND EXTREME
E-CENTRAL NEB...SWRN IA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 221529Z - 221730Z

WIDELY SCATTERED TSTMS MAY DEVELOP ROUGHLY BETWEEN SLN-OMA THROUGH
18Z AND MOVE RAPIDLY NEWD 35-45 KT ACROSS DISCUSSION AREA.  ALTHOUGH
ACTIVITY IS FCST TO REMAIN ROOTED ABOVE SFC...OCCASIONAL LARGE HAIL
IS POSSIBLE.  WW NOT ANTICIPATED FOR THIS SHORT-TERM REGIME BUT MAY
BE REQUIRED LATER IN DAY...PER SITUATION DESCRIBED IN SWODY1
CONVECTIVE OUTLOOK.  

MODIFIED 12Z RAOBS AND RUC FCST SOUNDINGS INDICATE STRONG CAP
REMAINING IN PLACE NOW...AND FOR AT LEAST ANOTHER 3-4 HOURS BASED ON
FCST BOUNDARY LAYER THERMODYNAMICS.  ROUGHLY 7-10 DEG F SFC HEATING
REQUIRED FOR ACTIVITY TO BE SFC-BASED WILL BE SLOW TO MATERIALIZE
BECAUSE OF EXTENSIVE CLOUD COVER LIMITING DIABATIC HEATING. 
HOWEVER...STEEP LAPSE RATES ARE NOTED ABOVE CAPPING LAYER -- AT
LEAST 8 DEG C/KM BETWEEN 700-850 MB...ALONG WITH INCREASING MOISTURE
ASSOCIATED WITH 40-50 KT LLJ.  AREA WAS ALONG AND JUST W OF 850 MB
ISODROSOTHERMAL AXIS AT 12Z AND SHOULD REMAIN SO FOR SEVERAL MORE
HOURS WHILE MOISTURE ADVECTS NEWD INTO IA.  THIS RESULTS IN MUCAPE
2000-3000 J/KG...IN ENVIRONMENT CHARACTERIZED BY ROUGHLY 40 KT SHEAR
THROUGH LOWEST 6 KM OF ELEVATED INSTABILITY.

..EDWARDS.. 10/22/2004

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

ATTN...WFO...DMX...EAX...FSD...OAX...TOP...ICT...GID...

39069818 40009791 41229763 42279622 42129501 41369519
40539566 39599630 38599721

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 22, 12:11 PM CDT	Mesoscale Discussion	SPC	Allamakee, Appanoose, Benton, Black Hawk, Bremer, Buchanan and 42 more	2 hr
Oct 22, 4:26 PM CDT	Mesoscale Discussion	SPC	Buena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 6 more	3 hr
Oct 22, 1:08 PM CDT	Mesoscale Discussion	SPC	Cherokee, Labette	2 hr
Oct 22, 2:02 PM CDT	Mesoscale Discussion	SPC	Antelope, Blaine, Boyd, Brown, Custer, Garfield and 11 more	118 min

Nearby

Mesoscale Discussions in Nebraska, 2004 Mesoscale Discussions in Kansas, 2004 Mesoscale Discussions in Iowa, 2004 Every mesoscale discussion in 2004

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.