Alert archive / Iowa / Severe Thunderstorm Warnings in 2004

Severe Thunderstorm Warning 17, NWS Quad Cities, IA

May 7, 2004Cedar County, Johnson County, Iowa

NWS Quad Cities, IA issued this severe thunderstorm warning at May 7, 2004, 6:54 AM CDT for Cedar County, Johnson County, Iowa. It was in force for 36 min. 16 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: May 7, 2004, 6:54 AM CDT (11:54 UTC)
Expired: May 7, 2004, 7:30 AM CDT
In force: 36 min
Issued by: NWS Quad Cities, IA
Area: Counties, with a storm outline in the text

Counties Cedar County, IA, Johnson County, IA

The radar

The Quad Cities radar (KDVN), 68 km from the middle of the area, began a volume at 11:54 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.

What was reported inside it

Time	Report	Where	Remark
May 7, 6:55 AM CDT	HAIL 0.88	Iowa City, IA
May 7, 6:55 AM CDT	HAIL 0.88	Iowa City, IA
May 7, 6:55 AM CDT	HAIL 1	E Iowa City, IA
May 7, 6:55 AM CDT	HAIL 1	E Iowa City, IA
May 7, 6:57 AM CDT	HAIL 0.75	Iowa City, IA	COVERING GROUND IN SOUTHEAST SECTION OF CITY.
May 7, 6:57 AM CDT	HAIL 0.75	Iowa City, IA	COVERING GROUND IN SOUTHEAST SECTION OF CITY.
May 7, 6:59 AM CDT	HAIL 1.25	1 E Iowa City, IA
May 7, 6:59 AM CDT	HAIL 1.25	1 E Iowa City, IA
May 7, 6:59 AM CDT	HAIL 2.5	1 S Iowa City, IA	REPORT RELAYED BY KWWL.
May 7, 6:59 AM CDT	HAIL 2.5	1 S Iowa City, IA	REPORT RELAYED BY KWWL.
May 7, 7:00 AM CDT	HAIL 1.75	Iowa City, IA	GOLF BALL HAIL, DENTING CARS IN IOWA CITY.
May 7, 7:00 AM CDT	HAIL 1.75	Iowa City, IA	GOLF BALL HAIL, DENTING CARS IN IOWA CITY.
May 7, 7:02 AM CDT	HAIL 1	Iowa City, IA	QUARTER SIZE HAIL COVERING GROUND AND ROAD.
May 7, 7:02 AM CDT	HAIL 1	Iowa City, IA	QUARTER SIZE HAIL COVERING GROUND AND ROAD.
May 7, 7:18 AM CDT	HAIL 0.75	3 N West Liberty, IA	OCCURING FOR PAST 5 MINUTES.
May 7, 7:18 AM CDT	HAIL 0.75	3 N West Liberty, IA	OCCURING FOR PAST 5 MINUTES.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 5 storm reports to this severe thunderstorm warning; the first came 1 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 11.9 hours before the alert went out and 74 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: 2446 J/kg
Mixed-layer CIN: -45 J/kg
Mixed-layer LCL: 1583 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 113 m²/s²
0-3 km storm-relative helicity: 217 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 9.0

Open this sounding in Storm Lab

The text

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

793 
WUUS53 KDVN 071154
SVRDVN
IAC031-103-071230-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
653 AM CDT FRI MAY 7 2004

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN CEDAR COUNTY IN EAST CENTRAL IOWA
  CENTRAL JOHNSON COUNTY IN EAST CENTRAL IOWA

* UNTIL 730 AM CDT

* AT 649 AM CDT...TRAINED SPOTTERS REPORTED A SEVERE THUNDERSTORM
  CAPABLE OF PRODUCING LARGE DAMAGING HAIL UP TO GOLF BALL SIZE. 
  THIS STORM WAS LOCATED NEAR IOWA CITY...OR ABOUT OVER IOWA CITY...
  AND MOVING EAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  8 MILES SOUTH OF TIPTON BY 730 AM CDT

SPOTTERS HAVE REPORTED HAIL UP TO THE SIZE OF GOLFBALLS IN 
IOWA CITY.

THIS IS A DANGEROUS STORM. MOVE IMMEDIATELY INDOORS AND STAY AWAY
FROM WINDOWS.

LAT...LON 4172 9164 4152 9162 4152 9138 4161 9137
          4161 9104 4178 9107

$$

LRE

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Quad Cities, IA wrote its last area forecast discussion before this severe thunderstorm warning went out at May 6, 3:31 PM CDT, 15 hours 23 minutes earlier.

Area forecast discussion, May 6, 3:31 PM CDT, 15 hours 23 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
331 PM CDT THU MAY 6 2004

.SYNOPSIS...1024 MB SURFACE HIGH OVER ND WAS SLOWLY PUSHING A
SURFACE COLD FRONT SOUTH ACROSS THE FORECAST AREA THIS AFTERNOON. AT
19Z...THIS FRONT STRETCHED FROM ABOUT RFD THROUGH CID AND DSM TO A
WEAK LOW OVER FAR SE NEB. 2-4 MB  3 HOUR PRESSURE RISES BEHIND THE
FRONT IN MN INDICATE SOUTHWARD MOVEMENT CONFIRMED BY SURFACE OBS
TODAY. 12Z DVN SOUNDING AND RECENT GOES SOUNDINGS INDICATE STRONG
CAP IN PLACE AS RESULT OF UNSEASONABLY WARM TEMPS IN H7 TO H85
LAYER. SCATTERED ELEVATED SHOWERS AND ISOLATED
THUNDERSTORMS...MOSTLY VIRGA PRODUCERS...CONTINUE ALONG AND NORTH OF
THE SURFACE FRONTAL BOUNDARY. THE STRONG CAP RESULTING IN CONVECTIVE
TEMPS NEAR OR ABOVE 100 DEG F THIS AFTERNOON WILL PREVENT SURFACE
BASED CONVECTION...BUT WILL STILL HAVE THREAT OF ELEVATED CONVECTION
THIS EVENING.
&&

.SHORT TERM...(TONIGHT THROUGH SATURDAY)...THUNDERSTORM CHANCES MAIN
CHALLENGE THROUGHOUT FORECAST AS SURFACE BOUNDARY LINGERS IN AREA
THROUGH MIDDLE PART OF NEXT WEEK. TONIGHT...WEAK MID LEVEL SHORTWAVE
SEEN ON WV IMAGERY IN SW MN INTO NEB WILL TRACK ACROSS AREA TO
ENHANCE THE SCATTERED ELEVATED SHOWERS INTO MORE SERIOUS
THUNDERSTORMS NORTH OF THE FRONT. SHORT TERM MODELS IN GOOD AGREEMENT
THE FRONT WILL REACH IA/MO BORDER AROUND MIDNIGHT WHICH LOOKS
REASONABLE BASED ON CURRENT TRENDS. 88DS SHOW WIDESPREAD VIRGA
MAINLY NORTH OF I-80 WHICH SHOULD BE ENHANCED INTO MORE WIDESPREAD
SHOWERS AND THUNDERSTORMS AFTER SUNSET WITH INCREASING H85 MOISTURE
POOLING ALONG THIS ELEVATED CONVERGENCE ZONE. HAVE LIKELY POPS
ACROSS CENTRAL CWA WITH BUFFER OF SCATTERED POPS TO NORTH AND SOUTH.
MAIN SEVERE THREAT WILL BE LARGE HAIL WITH THESE ELEVATED STORMS.
FRIDAY...THE FRONT LIFTS BACK NORTH LATE IN DAY WITH SCATTERED
ELEVATED SHOWERS AND THUNDERSTORMS CONTINUING OVER THE CWA. HAVE
ADJUSTED TEMPS DOWN CONSIDERABLY...ESPECIALLY IN FAR NORTHEAST WHERE
EASTERLY FLOW WILL LIMIT HIGHS TO AROUND 60...WHILE FAR SOUTH MAY
SEE 80 BY LATE AFTERNOON. THE FRONT LIFTS NORTH INTO HIGHWAY 20
CORRIDOR IN THE EVENING WITH MUCH MORE FAVORABLE LOW LEVEL JET
FEEDING INTO AREA FOR SEVERE POTENTIAL ALONG AND NORTH OF FRONT AND
AGAIN HAVE LIKELY POPS IN NORTH. ON SATURDAY...FRONT CONTINUES TO
WAVER ACROSS THE AREA WITH FORECAST SOUNDINGS LOOKING MORE FAVORABLE
FOR SURFACE BASED CONVECTION...ESPECIALLY IN AFTERNOON WITH WEAKER
MID LEVEL CAPPING. SEVERE POTENTIAL CONTINUES WITH ABUNDANT MOISTURE
POOLING IN AREA...MODERATE INSTABILITY IN AFTERNOON AND LOW LEVEL
SHEAR ALONG FRONT.

.LONG TERM...(SATURDAY NIGHT THROUGH THROUGH THURSDAY)...ZONAL MID
LEVEL FLOW AND LINGERING FRONT WILL KEEP PERIODIC CHANCES FOR
THUNDERSTORMS GOING THROUGH THURSDAY. MEDIUM RANGE GUIDANCE
PUSHES UPPER TROUGH INTO CENTRAL CONUS TOWARD THURSDAY TO ALLOW
CANADIAN AIRMASS TO WIN OUT AND PUSH FRONT WELL SE OF AREA THURSDAY
NIGHT FOR BREAK FROM PROLONGED WET PATTERN.
&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.

&&

SHEETS

Hazardous weather outlook, May 7, 5:46 AM CDT, 1 hour 8 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
546 AM CDT FRI MAY 7 2004

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-009-
015>018-024>026-034-035-MOZ009-010-081000-
BENTON IA-BUCHANAN IA-BUREAU IL-CARROLL IL-CEDAR IA-CLARK MO-CLINTON IA-
DELAWARE IA-DES MOINES IA-DUBUQUE IA-HANCOCK IL-HENDERSON IL-HENRY IA-
HENRY IL-IOWA IA-JACKSON IA-JEFFERSON IA-JO DAVIESS IL-JOHNSON IA-
JONES IA-KEOKUK IA-LEE IA-LINN IA-LOUISA IA-MCDONOUGH IL-MERCER IL-
MUSCATINE IA-PUTNAM IL-ROCK ISLAND IL-SCOTLAND MO-SCOTT IA-
STEPHENSON IL-VAN BUREN IA-WARREN IL-WASHINGTON IA-WHITESIDE IL-
546 AM CDT FRI MAY 7 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST IOWA...
EAST CENTRAL IOWA...SOUTHEAST IOWA...NORTHWEST ILLINOIS...NORTH
CENTRAL ILLINOIS...WEST CENTRAL ILLINOIS AND NORTHEAST MISSOURI.

.DAY ONE...TODAY AND TONIGHT

STRONG THUNDERSTORMS WILL GRADUALLY MOVE SOUTHEAST ACROSS AREAS ALONG
AND SOUTH OF INTERSTATE 80 EARLY THIS MORNING.  THESE STORMS WILL HAVE
THE POTENTIAL TO PRODUCE SMALL HAIL AND GUSTY WINDS UP TO 50 MPH.
HEAVY RAIN WILL ALSO BE POSSIBLE...WITH SOME PLACES RECEIVING OVER AN
INCH BEFORE THE RAIN ENDS.  SCATTERED SHOWERS AND A FEW ISOLATED
THUNDERSTORMS WILL BE POSSIBLE THROUGH THE AFTERNOON. ANOTHER ROUND OF
THUNDERSTORMS...POSSIBLY STRONG TO SEVERE...WILL OCCUR TONIGHT.  THE
MAIN THREAT FROM THESE STORMS WILL BE LARGE HAIL.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH FRIDAY

A VERY ACTIVE PERIOD OF WEATHER IS EXPECTED THROUGH THE WEEKEND AND
EARLY NEXT WEEK. THERE IS A POTENTIAL FOR AT LEAST TWO ROUNDS OF
SEVERE WEATHER DURING THIS TIME PERIOD...ALONG WITH MODERATE TO
POSSIBLY HEAVY RAINFALL.

DURING THE LATE AFTERNOON AND OVERNIGHT HOURS...THE COMBINATION OF
MOISTURE AND SHEAR PROVIDED BY THE FRONT SHOULD BE ENOUGH TO ALLOW
PERIODS OF STRONG TO SEVERE STORMS TO DEVELOP SATURDAY THROUGH THURSDAY.
IF SEVERE STORMS DEVELOP...HAIL AND DAMAGING WINDS WOULD BE THE PRIMARY
THREAT.

ONE FINAL THREAT WILL BE THE AMOUNT OF RAINFALL FROM TONIGHT THROUGH
THURSDAY. IF MODERATE TO HEAVY RAINFALL WOULD OCCUR...AREA
RIVERS WOULD EXPERIENCE GENERAL RISES.

EMERGENCY MANAGERS SHOULD LISTEN TO LATER FORECASTS REGARDING THE
POTENTIAL FOR SEVERE WEATHER THROUGH THE WEEKEND.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED ONE OR MORE TIMES BETWEEN TODAY AND
THURSDAY.

ERVIN

In the hours before

Local storm report, May 7, 5:16 AM CDT, 1 hour 38 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
516 AM CDT FRI MAY 07 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0511 AM     HAIL             1 W GALVA               42.51N 95.44W
05/07/2004  0.88 INCH        IDA                IA   TRAINED SPOTTER

0502 AM     TSTM WND GST     GALVA                   42.51N 95.42W
05/07/2004  50 MPH           IDA                IA   TRAINED SPOTTER

0436 AM     HAIL             STOCKTON                41.58N 90.87W
05/07/2004  0.25 INCH        MUSCATINE          IA   LAW ENFORCEMENT

            WITH HEAVY RAIN.

&&

SK

Local storm report, May 7, 5:20 AM CDT, 1 hour 34 minutes before

PRELIMINARY LOCAL STORM REPORT ... CORRECTION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
520 AM CDT FRI MAY 07 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0511 AM     HAIL             1 W GALVA               41.17N 90.06W
05/07/2004  0.88 INCH        HENRY              IL   TRAINED SPOTTER

0502 AM     TSTM WND GST     GALVA                   41.17N 90.04W
05/07/2004  50 MPH           HENRY              IL   TRAINED SPOTTER

&&
CORRECTED TO CHANGE COUNTY, STATE AND LAT/LON.

SK

Local storm report, May 7, 5:58 AM CDT, 56 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
558 AM CDT FRI MAY 07 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0548 AM     HAIL             1 E DEPUE               43.25N 89.33W
05/07/2004  1.75 INCH        DANE               WI   TRAINED SPOTTER

            HEAVY RAIN AND 30-40 MPH GUSTS.

0530 AM     HEAVY RAIN       MUSCATINE               41.42N 91.07W
05/07/2004  1.10 INCH        MUSCATINE          IA   TRAINED SPOTTER

            ONE AND ONE TENTH OF AN INCH IN THE PAST 30 MINUTES.

&&

SK

Local storm report, May 7, 6:11 AM CDT, 43 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
611 AM CDT FRI MAY 07 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0555 AM     HAIL             GRANVILLE               41.26N 89.23W
05/07/2004  0.88 INCH        PUTNAM             IL   EMERGENCY MNGR

&&

ERVIN

Local storm report, May 7, 6:12 AM CDT, 42 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
612 AM CDT FRI MAY 07 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0600 AM     HAIL             SPRING VALLEY           41.33N 89.20W
05/07/2004  0.88 INCH        BUREAU             IL   LAW ENFORCEMENT

&&

ERVIN

Local storm report, May 7, 6:54 AM CDT, 0 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
654 AM CDT FRI MAY 07 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0405 AM     TSTM WND DMG     ATALISSA                41.57N 91.17W
05/07/2004                   MUSCATINE          IA   LAW ENFORCEMENT

            SIGNIFICANT POWERLINE DAMAGE, 2 SEMI TRAILERS BLOWN OVER.

&&

ERVIN

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 7, 1:56 AM CDT	Severe Thunderstorm Warning	DVN	Benton	64 min
May 7, 2:33 AM CDT	Severe Thunderstorm Warning	DVN	Jones, Linn	57 min
May 7, 3:49 AM CDT	Severe Thunderstorm Warning	DVN	Cedar, Muscatine, Scott	26 min
May 7, 4:15 AM CDT	Severe Thunderstorm Warning	DVN	Scott	30 min
May 7, 8:13 AM CDT	Severe Thunderstorm Warning	DVN	Scott	47 min
May 7, 10:35 AM CDT	Severe Thunderstorm Warning	DVN	Cedar, Johnson	55 min
May 7, 11:04 AM CDT	Severe Thunderstorm Warning	DVN	Benton, Linn	56 min
May 7, 11:43 AM CDT	Severe Thunderstorm Warning	DVN	Jones	32 min
May 7, 4:21 PM CDT	Severe Thunderstorm Warning	DVN	Delaware, Dubuque	54 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2004 Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.