Alert archive / Iowa / Severe Thunderstorm Warnings in 1996

Severe Thunderstorm Warning 11, NWS Quad Cities, IA

April 18, 1996Clayton County, Iowa

NWS Quad Cities, IA issued this severe thunderstorm warning at Apr 18, 1996, 1:55 PM CDT for Clayton County, Iowa. It was in force for 50 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Apr 18, 1996, 1:55 PM CDT (18:55 UTC)
Expired: Apr 18, 1996, 2:45 PM CDT
In force: 50 min
Issued by: NWS Quad Cities, IA
Area: Whole counties

County Clayton County, IA

What was reported inside it

Time	Report	Where	Remark
Apr 18, 2:00 PM CDT	Hail 1	Clayton, IA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 6.9 hours before the alert went out and 153 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: 1782 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 278 m²/s²
0-3 km storm-relative helicity: 276 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 Apr 18, 1:05 PM CDT, 50 minutes earlier.

Area forecast discussion, Apr 18, 1:05 PM CDT, 50 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
104 PM CDT WED APR 17 1996

17Z ADAP STREAMLINE/WIND PLOT INDICATED COLD FRONT APPROACHING I-35.
FRONT BECOMING PARALLEL TO FLOW SINCE WINDS BACKING IN MID LEVELS
AS PER PLAINVIEW PROFILIER COMPOSITES. THIS IN TURN WILL ALLOW MOISTURE
IN THE FORM OF LOWER TO MID 50 SFC TD'S TO REACH THE MISSISSIPPI RIVER
VALLEY BEFORE FROPA. "BULLS-EYE" OF MOISTURE FLUX CONVERGENCE NEAR
KDMX. LATEST KDVN 88-D VOLUME SCAN INDICATED VIL TO 47 JUST WEST OF
KDMX BUT LIKELY OVER-ESTIMATING. 32 VIL AT ALO AIRPORT ASSOCIATED WITH
1/2 INCH SIZE HAIL.

NEW ETA/NMG SLOW FRONT DOWN A BIT WHICH INCREASES SVR THREAT FOR E
IA/NW ILL LATE THIS AFTERNOON AND EARLY EVENING... ALLOWING AMPLE TIME
FOR MOISTURE RETURN. 18Z KDVN SOUNDING AVBL AND SHOWED SUPER-ADIABATIC
LAPSE RATES (12.9 C) FROM 700-500 MB... LI -1... TT 54... WET BULB ZERO
12500 KFT AND SR HELICIITY (0-3KM) OF 235. B+ ONLY 379 HOWEVER AND CAP
STRENGTH 3.0 C. CAP TO ERODE AS STRONG SHORTWAVE APPROACHES... BUT
EXTENSIVE AC/CI ON LATEST VISIBLE TO LIMIT UPDRAFT STRENGTH (MEAGER
CAPES). DELTA THETA-E FROM SFC TO 500 MB 16 WHICH IS MARGINAL FOR WET
MICROBURST (+20 BETTER). JUST WARNED FOR CLAYTON COUNTY (DIME SIZE HAIL
WITH VIL TO 29!). BOX DUE OUT SHORTLY I'LL BET. LARGE HAIL MAIN THREAT.

CID 045/70  DBQ 047/70  MLI 046/70  BRL 050/70

HENDRICKS

In the hours before

Special weather statement, Apr 18, 10:57 AM CDT, 2 hours 58 minutes before

IAZ030-040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-
002-007-009-015>018-024>026-034-035-200000-

SIGNIFICANT WEATHER OUTLOOK FOR EASTERN IOWA AND NORTHWEST ILLINOIS
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1056 AM CDT THU APR 18 1996

...SEVERE THUNDERSTORMS POSSIBLE THIS AFTERNOON...

A COLD FRONT WILL MOVE THROUGH EASTERN IOWA AND NORTHWEST ILLINOIS THIS
AFTERNOON AND EARLY EVENING... POSSIBLY SPAWNING SEVERE THUNDERSTORMS.
POSITIVE FACTORS FOR THIS EVENT INCLUDE A STRONG LOW-LEVEL JET PASSING
OVER EASTERN IOWA AND NORTHWEST ILLINOIS. IN ADDITION... STRONG SOLAR
HEATING THIS AFTERNOON WILL COINCIDE WITH FRONTAL PASSAGE AND POTENT
UPPER DYNAMICS... FURTHER ENHANCING THE THREAT. HOWEVER... THE
APPROACHING COLD FRONT WILL ONLY HAVE SHALLOW LOW LEVEL MOISTURE TO WORK
WITH... INHIBITING DEVELOPMENT. ALSO... A SIGNIFICANT CAP/MID-LEVEL
TEMPERATURE INVERSION IN PLACE OVER THE REGION SHOULD KEEP THINGS QUIET
THROUGH MID AFTERNOON.

IF SEVERE WEATHER DOES DEVELOP... IT WILL MOST LIKELY BE AFTER 300 PM.
THE RAPID MOVEMENT OF THE STORMS WOULD KEEP IT FROM LASTING PAST
700 PM. AT THIS POINT... THE GREATEST POTENTIAL FOR DAMAGING WIND AND
LARGE HAIL APPEARS TO BE EAST OF THE MISSISSIPPI AND SOUTH OF I-80.

SPOTTER ACTIVATION MAY BE REQUIRED THIS AFTERNOON AND EARLY EVENING.

HENDRICKS

Local storm report, Apr 18, 1:23 PM CDT, 32 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
120 PM CDT THU APR 18 1996

TIME(CDT)  .....CITY LOCATION.....   ST   ...EVENT/REMARKS...
DATE(CDT)  ....COUNTY LOCATION....

1257 PM    ELKADER                   IA   0.75 INCH HAIL_
04/18/96   CLAYTON

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 18, 1:01 PM CDT	Severe Thunderstorm Warning	DVN	Clayton	29 min
Apr 18, 1:34 PM CDT	Severe Thunderstorm Warning	DVN	Buchanan	26 min
Apr 18, 3:52 PM CDT	Severe Thunderstorm Warning	DVN	Jefferson	53 min
Apr 18, 3:54 PM CDT	Severe Thunderstorm Warning	DVN	Iowa	51 min
Apr 18, 3:59 PM CDT	Severe Thunderstorm Warning	DVN	Henry	46 min
Apr 18, 4:42 PM CDT	Severe Thunderstorm Warning	DVN	Henry	48 min
Apr 18, 4:44 PM CDT	Severe Thunderstorm Warning	DVN	Johnson	31 min
Apr 18, 5:10 PM CDT	Severe Thunderstorm Warning	DVN	Lee	50 min
Apr 18, 5:10 PM CDT	Severe Thunderstorm Warning	DVN	Des Moines	50 min
Apr 18, 5:48 PM CDT	Severe Thunderstorm Warning	DVN	Scott	42 min
Apr 18, 5:45 PM CDT	Severe Thunderstorm Warning	DVN	Henderson	45 min
Apr 18, 5:55 PM CDT	Tornado Warning	DVN	Hancock, McDonough	50 min
Apr 18, 6:09 PM CDT	Severe Thunderstorm Warning	DVN	McDonough	36 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1996 Every severe thunderstorm warning in 1996

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.