Alert archive / Iowa / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 124, NWS Quad Cities, IA

October 1, 2002Jefferson County, Van Buren County, Iowa

NWS Quad Cities, IA issued this severe thunderstorm warning at Oct 1, 2002, 11:24 PM CDT for Jefferson County, Van Buren County, Iowa. It was in force for 66 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
Oct 1, 2002, 11:24 PM CDT (04:24 UTC)
Expired
Oct 2, 2002, 12:30 AM CDT
In force
66 min
Issued by
NWS Quad Cities, IA
Area
Counties, with a storm outline in the text

Counties Jefferson County, IA, Van Buren County, IA

The radar

The Quad Cities radar (KDVN), 140 km from the middle of the area, began a volume at 04:28 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

TimeReportWhereRemark
Oct 1, 11:30 PM CDTThunderstorm Wind 61 EFairfield, IAThe northwest portion of the Maharishi University of Management campus sustained considerable damage. At least 20 trees were blown over, mainly along Zimmerman Boulevard. One vehicle and two trailers were also damaged, and the entire length of a fence around

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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Oct 1, 8:40 PM CDTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 4.4 hours before the alert went out and 146 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 00:00Z on 2002-10-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 277 joules per kilogram.LCLLFCEL10008507005003002001001 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 00:00Z on 2002-10-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 288 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
277 J/kg
Mixed-layer CIN
-113 J/kg
Mixed-layer LCL
1072 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
288 m²/s²
0-3 km storm-relative helicity
564 m²/s²
Significant tornado parameter
0.5
Supercell composite
2.1

Open this sounding in Storm Lab

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 Oct 1, 2:05 PM CDT, 9 hours 19 minutes earlier.

Area forecast discussion, Oct 1, 2:05 PM CDT, 9 hours 19 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
205 PM CDT TUE OCT 1 2002

ACTIVE WEATHER PATTERN UNFOLDING FOR REGION THROUGH THE WEEKEND.
MID LEVEL SW FLOW STRENGTHENING AS WEST COAST TROUGH DEEPENS AND
UPPER RIDGE HOLDING ON OVER SERN U.S.  MSAS PLACES SURFACE FRONT
ACROSS NW IA THROUGH ERN NE INTO WAVE OVER NORTH CENTRAL KS.  WATER
VAPOR LOOP SHOWS EMBEDDED S/W OVER ERN NE AT 18Z WHICH SUPPORTING
CLUSTER OF
SHRA/TSRA FROM CENTRAL INTO E CENTRAL/NE IA.  TSRA LIGHTING ON
SOUTHERN FRINGE OF CLUSTER AS IT ENCOUNTERS MORE AVAILABLE
INSTABILITY OVER NE MO/CENTRAL IL.

IN THE SHORT TERM MODELS ARE IN AGREEMENT MOVING ERN NE IMPULSE ENE
INTO WI THIS EVENING AND SHOVING SURFACE FRONT SE TO NEAR A
STJ-MLI-RFD LINE BY 12Z WEDNESDAY.  MODELS...ESPECIALLY
AVN...ADVERTISING A COUPLED JET STRUCTURE EVOLVING OVERNIGHT AS
SOUTH CENTRAL CANADA JET INCREASES TO AROUND 12OKTS AND WITH A 100KT
JET NOSING INTO CENTRAL NE BY 12Z WED.  THIS COMBINED WITH 850 FRONT
OVER IA AND PW AROUND 1.5 INCHES SHOULD PROVIDE LIFT...GOOD MOISTURE
SOURCE AND FOCUS FOR SOME DECENT RAINS LATE TONIGHT AND EARLY
WEDNESDAY OVER NORTHERN SECTIONS OF CWA.  CURRENT FORECAST PACKAGE
ALREADY HAS HEAVY RAIN MENTIONED AND WILL CONTINUE.  A SURFACE WAVE
RIDING ALONG THE FRONT WEDNESDAY KEEPS FRONT FROM MOVING MUCH
WEDNESDAY MORNING THEN FRONT MOVES SOUTHEAST INTO IL/NRN MO BY 00Z
THURSDAY.  WILL TAPER POPS OFF NORTH AFTER WEDNESDAY MORNING AND
KEEP AT LEAST LIKELYS GOING SOUTH FOR RAIN/TSRA. THURSDAY NIGHT
FRONT LIFTS BACK NORTH IN RESPONSE TO STRONG S/W LIFTING OUT OF S.W.
TROUGH.  BY 12Z AVN PLACES FRONT OVER NW CORNER OF CWA.  THE ETA IS
NOT QUITE AS AGRESSIVE PLACING FRONT NEAR A CID/DBQ LINE BY EARLY
FRIDAY.  AVN HAS BEEN THE PREFFERED MODEL ALL ALONG AND WILL TREND
TOWARD THE AVN SOLUTION FOR THURSDAY/FRIDAY. AVN MOVES SURFACE LOW
RAPIDLY NORTHEAST FRIDAY WITH COLD FRONT MOVING EAST OF CWA BY 00Z
SATURDAY.

TEMPS THROUGH THE PERIOD WILL BE A HEADACHE WITH STRONG BAROCLINIC
ZONE WAFFLING OVER CWA NEXT FEW DAYS.  AGAIN AVN IS THE PREFERRED
MODEL ...SO WILL STAY CLOSE TO THE MAV NUMBERS.

.EXTENDED...SATURDAY THROUGH TUESDAY
S/W ENERGY MOVING OUT OF WESTERN U.S. WILL PROVIDE ANOTHER CHANCE OF
RAIN FOR SUNDAY.  TIMING WILL BE AN ISSUE WITH MRF/CANADIAN
SUGGESTING SURFACE LOW WILL MOVE THROUGH REGION EARLY SUNDAY...BUT
UKMET IS CONSIDERABLY SLOWER WITH SURFACE TROF OVER THE FRONT RANGE
AT 12Z SUNDAY. 12Z AVN IS ALSO SHOWING SYSTEM DIGGING AND CLOSING
OFF OVER SOUTHERN ROCKIES SUNDAY...WHICH ALSO LENDS SUPPORT FOR
SLOWER SOLUTIONS. FOR NOW WILL GO WITH A BLEND AND INTRODUCE SHRA
FOR SUNDAY.  SINCE THERE IS SOME CONSIDERABLE DIFFERENCES IN TIMING
WITH THIS SYSTEM...WILL STAY A LITTLE ABOVE MEX  NUMBERS FOR MONDAY.

.DVN...
IA...NONE.
IL...NONE.
MO...NONE.

Nearby

Severe Thunderstorm Warnings in Iowa, 2002Every severe thunderstorm warning in 2002

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; radar from the NEXRAD Level II archive.