Alert archive / Iowa / Mesoscale Discussions in 2005

Mesoscale Discussion 4

January 1, 200520 counties in Illinois; 32 counties in Iowa; 17 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jan 1, 2005, 12:45 PM CST for 20 counties in Illinois; 32 counties in Iowa; 17 counties in Wisconsin. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Jan 1, 2005, 12:45 PM CST (18:45 UTC)
Expired
Jan 1, 2005, 4:45 PM CST
In force
4 hr
Issued by
the Storm Prediction Center
All 69 counties

Allamakee County, IA, Benton County, IA, Black Hawk County, IA, Bremer County, IA, Buchanan County, IA, Butler County, IA, Cedar County, IA, Chickasaw County, IA, Clayton County, IA, Clinton County, IA, Delaware County, IA, Dubuque County, IA, Fayette County, IA, Franklin County, IA, Grundy County, IA, Hardin County, IA, Iowa County, IA, Jackson County, IA, Jasper County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Linn County, IA, Louisa County, IA, Marshall County, IA, Muscatine County, IA, Poweshiek County, IA, Scott County, IA, Story County, IA, Tama County, IA, Washington County, IA, Winneshiek County, IA, Boone County, IL, Bureau County, IL, Carroll County, IL, DeKalb County, IL, DuPage County, IL, Henry County, IL, Jo Daviess County, IL, Kane County, IL, Kendall County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, McHenry County, IL, Mercer County, IL, Ogle County, IL, Putnam County, IL, Rock Island County, IL, Stephenson County, IL, Whiteside County, IL, Winnebago County, IL, Columbia County, WI, Crawford County, WI, Dane County, WI, Dodge County, WI, Grant County, WI, Green County, WI, Iowa County, WI, Jefferson County, WI, Kenosha County, WI, Lafayette County, WI, Richland County, WI, Rock County, WI, Sauk County, WI, Vernon County, WI, Walworth County, WI, Washington County, WI, Waukesha County, WI

The radar

The Quad Cities radar (KDVN), 67 km from the middle of the area, began a volume at 18:48 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

Davenport, (KDVN), launched 12:00Z, 6.8 hours before the alert went out and 68 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, Davenport, at 12:00Z on 2005-01-01Temperature 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, Davenport, at 12:00Z on 2005-01-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 120 square meters per square second.19395878Sfc1 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
1502 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
120 m²/s²
0-3 km storm-relative helicity
163 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.

316 
ACUS11 KWNS 011845
SWOMCD
SPC MCD 011845 
ILZ000-WIZ000-IAZ000-MNZ000-012245-

MESOSCALE DISCUSSION 0004
NWS STORM PREDICTION CENTER NORMAN OK
1245 PM CST SAT JAN 01 2005

AREAS AFFECTED...CENTRAL/ERN IA...SRN WI AND PORTIONS OF NRN IL

CONCERNING...FREEZING RAIN AND SLEET 

VALID 011845Z - 012245Z

A MIX OF FREEZING RAIN AND SLEET WILL CONTINUE ACROSS THE REGION
THROUGH AFTERNOON...WITH DEVELOPMENT INTO SCENTRAL WI AND NRN IL
THROUGH 21Z. HRLY ACCUMULATIONS OF ICE FROM 0.05-0.10 INCHES WILL BE
POSSIBLE WITH THE HEAVIER CONVECTIVE SHOWERS.

LOW LEVEL ADVECTIVE COMPONENT WILL REMAIN WEAKER THAN FARTHER NORTH
THUS EXPECT OVERALL LIGHTER ACCUMULATIONS OF FREEZING RAIN/SLEET
THAN ACROSS FAR NRN IA/MN AND CENTRAL WI. HOWEVER...ISENTROPIC LIFT
NORTH OF SFC FRONT WILL REMAIN MODERATE AND COMBINED WITH ELEVATED
INSTABILITY...MUCAPES FROM 50-150 J/KG ...WILL SUPPORT HEAVIER
CONVECTIVE FREEZING RAIN/SLEET SHOWERS ACROSS THE AREA THROUGH 00Z.
AN EARLIER BAND OF PRECIPITATION THAT MOVED ACROSS CENTRAL/ERN IA
INTO SWRN WI HAS ALLOWED FOR SUFFICIENT SATURATION SO THAT ANY
ADDITIONAL PRECIPITATION WILL BE EFFICIENT IN REACHING THE GROUND.
LOW LEVEL WAA WILL LEAD TO NWD MOVEMENT OF THE SFC FREEZING LINE
THROUGH THE AFTERNOON...BUT SINCE SFC LOW MVMNT WILL BE ENEWD INTO
SERN NEB AND WET-BULB EFFECTS WILL BE OCCURRING...IT IS NOT
ANTICIPATED THAT THE SFC FREEZING LINE WILL MOVE MUCH NORTH OF I-80
THROUGH 00Z.

OVER SCENTRAL WI/NRN IL WHERE PRECIPITATION HAS NOT FALLEN MUCH
TODAY...A DELAY IN LOW-MID LEVEL SATURATION SHOULD PROVIDE FOR 
SLEET AS THE PREDOMINATE PTYPE FOR THE FIRST HOUR OR SO OF ONSET OF
PRECIP. PRECIP IS NOT ANTICIPATED TO CHANGE OVER TO FREEZING RAIN
OVER THE IMMEDIATE CHI METRO AREA...WHERE NELY WINDS OFF LK MI
SHOULD KEEP TEMPERATURES ABOVE FREEZING.

..CROSBIE.. 01/01/2005

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

...NOTICE...
SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A 
SCHEDULED BASIS...FOUR TIMES A DAY...BETWEEN 00-01 UTC...
06-07 UTC...12-13 UTC...AND 18-19 UTC AS SIGNIFICANT SHORT
RANGE WINTER WEATHER EVENTS UNFOLD.  THIS SCHEDULE WILL BE
USED FROM DECEMBER 1 THROUGH FEBRUARY 28.

ATTN...WFO...LOT...ILX...MKX...DVN...ARX...DMX...

43689076 42909326 42199377 41679346 41259186 41119084
41118952 41298867 41818767 43488808

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 1, 6:48 AM CSTMesoscale DiscussionSPCAllamakee, Benton, Black Hawk, Bremer, Buchanan, Butler and 29 more4 hr
Jan 1, 12:32 PM CSTMesoscale DiscussionSPCAllamakee, Buena Vista, Cerro Gordo, Chickasaw, Clay, Dickinson and 18 more5 hr
Jan 1, 1:01 PM CSTMesoscale DiscussionSPCBayfield, Burnett, Douglas, Washburn5 hr

Nearby

Mesoscale Discussions in Iowa, 2005Mesoscale Discussions in Illinois, 2005Mesoscale Discussions in Wisconsin, 2005Every mesoscale discussion in 2005

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.