Alert archive / Illinois / Mesoscale Discussions in 2004

Mesoscale Discussion 7

January 4, 20044 states

The Storm Prediction Center issued this mesoscale discussion at Jan 4, 2004, 9:27 AM CST for 4 states. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: Jan 4, 2004, 9:27 AM CST (15:27 UTC)
Expired: Jan 4, 2004, 1:30 PM CST
In force: 4 hr
Issued by: the Storm Prediction Center

All 72 counties

Bureau County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Ford County, IL, Grundy County, IL, Henry County, IL, Iroquois County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Knox County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, Marshall County, IL, McHenry County, IL, McLean County, IL, Ogle County, IL, Peoria County, IL, Putnam County, IL, Stark County, IL, Whiteside County, IL, Will County, IL, Woodford County, IL, Allen County, IN, Benton County, IN, Cass County, IN, DeKalb County, IN, Elkhart County, IN, Fulton County, IN, Huntington County, IN, Jasper County, IN, Kosciusko County, IN, LaGrange County, IN, Lake County, IN, LaPorte County, IN, Marshall County, IN, Miami County, IN, Newton County, IN, Noble County, IN, Porter County, IN, Pulaski County, IN, Saint Joseph County, IN, Starke County, IN, Steuben County, IN, Wabash County, IN, White County, IN, Whitley County, IN, Allegan County, MI, Barry County, MI, Berrien County, MI, Branch County, MI, Calhoun County, MI, Cass County, MI, Eaton County, MI, Hillsdale County, MI, Ingham County, MI, Jackson County, MI, Kalamazoo County, MI, Lenawee County, MI, Livingston County, MI, Monroe County, MI, Saint Joseph County, MI, Van Buren County, MI, Washtenaw County, MI, Defiance County, OH, Fulton County, OH, Henry County, OH, Paulding County, OH, Williams County, OH

The radar

The Chicago radar (KLOT), 97 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

Lincoln, IL (KILX), launched 12:00Z, 3.5 hours before the alert went out and 213 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 651 m above ground
0-6 km bulk shear: 99 kt
0-1 km storm-relative helicity: 194 m²/s²
0-3 km storm-relative helicity: 239 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.

284 
ACUS11 KWNS 041527
SWOMCD
SPC MCD 041527 
MIZ000-OHZ000-INZ000-ILZ000-IAZ000-041930-

MESOSCALE DISCUSSION 0007
NWS STORM PREDICTION CENTER NORMAN OK
0927 AM CST SUN JAN 04 2004

AREAS AFFECTED...CENTRAL/NRN IL...NRN IND...SRN LOWER MI...AND NWRN
OH

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 041527Z - 041930Z

AXIS OF HEAVY SNOW EXPECTED TO DEVELOP ENEWD ACROSS NRN IL/NRN
IND/SRN LOWER MI THROUGH THIS AFTERNOON. NARROW ZONE OF
SLEET/FREEZING RAIN FROM NEAR BMI ENEWD TO NEAR FWA WITH RATES
BRIEFLY TO 0.1/HR.

AT 15Z...IR IMAGERY INDICATES EXPANDING SHIELD OF COLD CLOUD TOPS
ACROSS NERN MO AND NRN/CENTRAL IL...OWING TO LEFT FRONT QUADRANT OF
100KT MID-LEVEL JET MOVING NEWD INTO THE REGION. ASSOCIATED HEIGHT
TROUGH WILL MOVE ENEWD ALONG INTENSE BAROCLINIC ZONE...WITH 700MB
LOW CENTER REACHING CHICAGO AREA BY 00Z. STRONG UPPER JET DYNAMICS
IN ADDITION TO AMPLE NWD ADVECTION OF MOIST LOW-LEVEL AIR ACROSS THE
MID-MS RIVER VALLEY SHOULD INTENSIFY PRECIPITATION SHIELD FROM NRN
IL ENEWD ACROSS NRN IND/SRN LOWER MI/NWRN OH DURING THE NEXT 6-9
HOURS. MODEL SOUNDINGS FAVOR A NARROW ZONE OF SLEET/FREEZING RAIN
FROM BMI ENEWD TO FWA AREA...WITH WARM ADVECTION CAUSING ABOVE
FREEZING TEMPERATURES IN 850-700MB LAYER. DRY SLOT EVIDENT ON MOSAIC
RADAR IMAGERY ACROSS NRN MO SHOULD PROPAGATE ACROSS CENTRAL
IL/CENTRAL IND THIS AFTERNOON RESULTING IN SHORTER DURATION OF
FREEZING PRECIPITATION. HOWEVER...JUST NORTH OF DRY SLOT...A
PERSISTENT AND ELONGATED BAND OF HVY SNOW IS LIKELY.
PRESENTLY...1/HR SNOWS ARE NOTED WITH ZONE OF STRONG WAA ACROSS
N-CENTRAL IL. ON THE MESOSCALE...HEAVY BANDED SNOW IS LIKELY ON NRN
FRINGE OF PRECIPITATION SHIELD...COINCIDENT WITH STRONG 700MB
FRONTOGENESIS AND HORIZONTAL DEFORMATION IN ADVANCE OF WAVE CYCLONE.
ANTICIPATE SNOWFALL RATES OF 1/HR FOR SEVERAL HOURS FROM NRN IL
ENEWD ACROSS FAR NRN IND/SRN LOWER MI THROUGH THIS AFTERNOON...WITH
LOCALLY HIGHER RATES POSSIBLE.

..BANACOS.. 01/04/2004

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

ATTN...WFO...CLE...DTX...IWX...GRR...IND...LOT...ILX...DVN...

41688353 40978429 40738602 40468794 40438901 40789035
41709034 42038984 42198972 42588675 42738534 42588334

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 4, 2:08 AM CST	Mesoscale Discussion	SPC	Brown, Calhoun, Cass, Champaign, Christian, Coles and 19 more	5 hr

Nearby

Mesoscale Discussions in Illinois, 2004 Mesoscale Discussions in Indiana, 2004 Mesoscale Discussions in Michigan, 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.