Alert archive / Illinois / Mesoscale Discussions in 2004

Mesoscale Discussion 908

May 26, 200437 counties in Illinois; 28 counties in Indiana; 16 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at May 26, 2004, 8:20 AM CDT for 37 counties in Illinois; 28 counties in Indiana; 16 counties in Missouri. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued
May 26, 2004, 8:20 AM CDT (13:20 UTC)
Expired
May 26, 2004, 9:45 AM CDT
In force
85 min
Issued by
the Storm Prediction Center
All 81 counties

Bond County, IL, Calhoun County, IL, Christian County, IL, Clark County, IL, Clay County, IL, Clinton County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, Edwards County, IL, Effingham County, IL, Fayette County, IL, Franklin County, IL, Gallatin County, IL, Greene County, IL, Hamilton County, IL, Jackson County, IL, Jasper County, IL, Jefferson County, IL, Jersey County, IL, Lawrence County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Perry County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Saline County, IL, Shelby County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Bartholomew County, IN, Brown County, IN, Clark County, IN, Clay County, IN, Crawford County, IN, Daviess County, IN, Dubois County, IN, Floyd County, IN, Gibson County, IN, Greene County, IN, Harrison County, IN, Jackson County, IN, Knox County, IN, Lawrence County, IN, Martin County, IN, Monroe County, IN, Orange County, IN, Owen County, IN, Perry County, IN, Pike County, IN, Posey County, IN, Scott County, IN, Spencer County, IN, Sullivan County, IN, Vanderburgh County, IN, Vigo County, IN, Warrick County, IN, Washington County, IN, City of Saint Louis, MO, Crawford County, MO, Franklin County, MO, Gasconade County, MO, Iron County, MO, Jefferson County, MO, Lincoln County, MO, Madison County, MO, Perry County, MO, Reynolds County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Warren County, MO, Washington County, MO

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 1.3 hours before the alert went out and 180 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, Lincoln, IL at 12:00Z on 2004-05-26Temperature 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, Lincoln, IL at 12:00Z on 2004-05-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -20 square meters per square second.1939587897117136Sfc1 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
1078 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
-20 m²/s²
0-3 km storm-relative helicity
43 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.

372 
ACUS11 KWNS 261321
SWOMCD
SPC MCD 261320 
KYZ000-INZ000-ILZ000-MOZ000-261445-

MESOSCALE DISCUSSION 0908
NWS STORM PREDICTION CENTER NORMAN OK
0820 AM CDT WED MAY 26 2004

AREAS AFFECTED...E-CNTRL/SERN MO INTO SRN IL

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 261320Z - 261445Z

STRONGEST STORMS WILL BE CAPABLE OF LARGE HAIL AND CONVECTIVE TRENDS
ARE BEING MONITORED FOR POSSIBLE WW ISSUANCE.

GRADUAL INCREASE IN ELEVATED STORM COVERAGE/INTENSITY HAS OCCURRED
OVER THE PAST HOUR FROM PIKE/LINCOLN COUNTIES IN E-CNTRL MO SWWD
INTO MILLER/CAMDEN COUNTIES. 12Z SGF SOUNDING INDICATES THAT STEEP
MID-LEVEL LAPSE RATES OF 7.5-8.5 C/KM ARE CONTRIBUTING TO A
MODERATELY UNSTABLE AIRMASS FOR ELEVATED PARCELS WITH MUCAPES AROUND
1500 J/KG. WATER VAPOR IMAGERY SUGGESTS THAT A LOW-AMPLITUDE
SHORTWAVE TROUGH AND ASSOCIATED 60-65KT MID-LEVEL JET MAX IS
PROVIDING BACKGROUND LARGE-SCALE ASCENT FOR EVOLVING STORMS.

POTENTIAL FOR LARGE HAIL WILL SPREAD EWD ACROSS PORTIONS OF SRN
IL/SWRN IND OVER THE NEXT FEW HOURS. ADDITIONALLY...STORMS MAY TEND
TO BECOME MORE SURFACE-BASED OVER THE COURSE OF THE MORNING...AND
GIVEN THE FAST SYSTEM MOVEMENT...DAMAGING WINDS WILL BECOME
INCREASINGLY LIKELY. THUS...A WW MAY BE REQUIRED.

..MEAD.. 05/26/2004

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

ATTN...WFO...LMK...IND...PAH...ILX...LSX...SGF...

38369167 39289075 39578991 39628802 39278582 38378566
38048618 37508970 37309121

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 25, 7:28 PM CDTMesoscale DiscussionSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 17 more92 min
May 26, 8:50 AM CDTSevere Thunderstorm WatchSPCBond, Clay, Clinton, Crawford, Edwards, Effingham and 25 more5 hr
May 26, 10:50 AM CDTMesoscale DiscussionSPCAlexander, Bond, Clay, Clinton, Crawford, Edwards and 28 more85 min
May 26, 1:10 PM CDTTornado WatchSPCAlexander, Franklin, Gallatin, Hamilton, Hardin, Jackson and 12 more8 hr
May 26, 3:32 PM CDTMesoscale DiscussionSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Jackson and 13 more88 min
May 26, 5:10 PM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Calhoun, Cass, Christian and 29 more65 min
May 26, 5:35 PM CDTSevere Thunderstorm WatchSPCAdams, Bond, Brown, Calhoun, Cass, Christian and 34 more5 hr
May 26, 5:57 PM CDTMesoscale DiscussionSPCAlexander, Franklin, Hamilton, Jackson, Jefferson, Johnson and 10 more93 min
May 26, 11:25 AM CDTSevere Thunderstorm WatchSPCClark, Crawford, Floyd, Harrison, Jefferson, Ohio and 3 more7 hr
May 26, 1:18 PM CDTMesoscale DiscussionSPCClark, Crawford, Floyd, Harrison, Jefferson, Ohio and 3 more87 min

Nearby

Mesoscale Discussions in Illinois, 2004Mesoscale Discussions in Indiana, 2004Mesoscale Discussions in Missouri, 2004Every 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.