Alert archive / Iowa / Mesoscale Discussions in 2003

Mesoscale Discussion 978

May 14, 2003Hancock County, Henderson County, Illinois; 39 counties in Iowa; 8 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at May 14, 2003, 3:23 PM CDT for Hancock County, Henderson County, Illinois; 39 counties in Iowa; 8 counties in Missouri. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued
May 14, 2003, 3:23 PM CDT (20:23 UTC)
Expired
May 14, 2003, 5:00 PM CDT
In force
97 min
Issued by
the Storm Prediction Center
All 49 counties

Adair County, IA, Adams County, IA, Appanoose County, IA, Audubon County, IA, Cass County, IA, Clarke County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Des Moines County, IA, Guthrie County, IA, Henry County, IA, Iowa County, IA, Jasper County, IA, Jefferson County, IA, Johnson County, IA, Keokuk County, IA, Lee County, IA, Louisa County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Monroe County, IA, Montgomery County, IA, Muscatine County, IA, Page County, IA, Polk County, IA, Pottawattamie County, IA, Poweshiek County, IA, Ringgold County, IA, Shelby County, IA, Taylor County, IA, Union County, IA, Van Buren County, IA, Wapello County, IA, Warren County, IA, Washington County, IA, Wayne County, IA, Hancock County, IL, Henderson County, IL, Clark County, MO, Harrison County, MO, Mercer County, MO, Nodaway County, MO, Putnam County, MO, Schuyler County, MO, Scotland County, MO, Worth County, MO

The radar

The Des Moines radar (KDMX), 90 km from the middle of the area, began a volume at 20:22 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, 8.4 hours before the alert went out and 220 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 12:00Z on 2003-05-14Temperature 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, Omaha, NE at 12:00Z on 2003-05-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2025 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
67 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.

146 
ACUS11 KWNS 142024
SWOMCD
SPC MCD 142023 
TXZ000-OKZ000-142230-

MESOSCALE DISCUSSION 0979
NWS STORM PREDICTION CENTER NORMAN OK
0323 PM CDT WED MAY 14 2003

AREAS AFFECTED...N TX / SRN OK...

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 142023Z - 142230Z

A CONDITIONAL SEVERE THUNDERSTORM POTENTIAL EXISTS ACROSS N TX AND
ADJACENT SRN OK AHEAD OF DRYLINE / INVOF W-E FRONT.  IF CAP WEAKENS
SUFFICIENTLY TO ALLOW DEEP CONVECTIVE DEVELOPMENT...WW WILL BE
REQUIRED.

LATEST SURFACE ANALYSIS SHOWS LOW NEAR ABI...WITH DRYLINE EXTENDING
FROM E OF ABI SWD TO NEAR JCT...AND THEN SWWD TO W OF DRT.  WARM
FRONT EXTENDS FROM THE LOW EWD -- N OF MWL / DFW TO NEAR GGG ATTM. 
BOUNDARY LAYER REMAINS MOIST EAST OF DRYLINE...AND WITH STEEP
MID-LEVEL LAPSE RATES IN PLACE...DAYTIME HEATING HAS ALLOWED AIRMASS
TO BECOME MODERATELY UNSTABLE...WITH 2000 TO 2500 J/KG MEAN-LAYER
CAPE INDICATED.  HOWEVER...MORNING FWD RAOB SHOWED VERY STRONG CAP
IN PLACE.

WITH SHORT-WAVE RIDGING BUILDING INTO THE REGION WEST OF SHORT-WAVE
TROUGH AXIS NOW ACROSS CENTRAL OK ACCORDING TO LATEST WV
IMAGERY...SYNOPTIC-SCALE UVV APPEARS TO BE SHIFTING INTO NERN TX. 
GIVEN LACK OF SIGNIFICANT CU DEVELOPMENT NEAR DRYLINE / LOW THUS
FAR...IT APPEARS THAT CAP WILL REMAIN IN PLACE AND MAIN SEVERE
THREAT EXISTS E OF THIS REGION -- ACROSS TORNADO WATCH 371.

HOWEVER...WE WILL CONTINUE TO MONITOR EVOLVING UVV FIELD / CAP
STRENGTH...AS ANY BREACH OF THE CAP ACROSS N TX WOULD LIKELY LEAD TO
RAPID SUPERCELL DEVELOPMENT GIVEN KINEMATIC / THERMODYNAMIC
ENVIRONMENT. 

..GOSS.. 05/14/2003

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

ATTN...WFO...FWD...OUN...SJT...

34339968 34439908 34099727 32869631 31809735 31649946
32669945 33399933

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 14, 12:36 PM CDTMesoscale DiscussionSPCAdams, Brown, Bureau, Cass, Champaign, Christian and 38 more84 min
May 14, 1:10 PM CDTSevere Thunderstorm WatchSPCBrown, Bureau, Cass, Champaign, DeWitt, Douglas and 33 more6 hr
May 14, 2:00 PM CDTSevere Thunderstorm WatchSPCHenderson, Mercer5 hr
May 14, 2:45 PM CDTMesoscale DiscussionSPCBureau, Cass, Champaign, Christian, Coles, DeWitt and 32 more60 min
May 14, 5:07 PM CDTMesoscale DiscussionSPCBrown, Bureau, Cass, Champaign, DeWitt, Douglas and 28 more113 min
May 14, 6:45 PM CDTSevere Thunderstorm WatchSPCBond, Brown, Calhoun, Cass, Champaign, Christian and 35 more5 hr
May 13, 8:38 PM CDTMesoscale DiscussionSPCFremont, Page2 hr
May 14, 12:40 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Boone, Cass, Clarke and 22 more95 min

Nearby

Mesoscale Discussions in Iowa, 2003Mesoscale Discussions in Missouri, 2003Mesoscale Discussions in Illinois, 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.