Alert archive / Iowa / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 73, NWS Quad Cities, IA

June 10, 1999Van Buren County, Iowa

NWS Quad Cities, IA issued this severe thunderstorm warning at Jun 10, 1999, 1:17 PM CDT for Van Buren County, Iowa. It was in force for 33 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jun 10, 1999, 1:17 PM CDT (18:17 UTC)
Expired: Jun 10, 1999, 1:50 PM CDT
In force: 33 min
Issued by: NWS Quad Cities, IA
Area: Whole counties

County Van Buren County, IA

The radar

The Quad Cities radar (KDVN), 149 km from the middle of the area, began a volume at 18:20 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 watch it was issued in

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

Issued	Product	Office	Lasted
Jun 10, 10:35 AM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 6.3 hours before the alert went out and 155 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: 588 J/kg
Mixed-layer CIN: -59 J/kg
Mixed-layer LCL: 1446 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 60 m²/s²
0-3 km storm-relative helicity: 63 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 Jun 10, 3:13 AM CDT, 10 hours 4 minutes earlier.

Area forecast discussion, Jun 10, 3:13 AM CDT, 10 hours 4 minutes before

AREA FORECAST DISCUSSION...CORECTED TO CHANGE WATCH
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
230 AM CDT THU JUN 10 1999

SFC ANALYSIS FROM 06Z INDICATING COLD FRONT ALONG WESTERN BORDER OF
IA...EXTENDED FROM A LOW CENTER OVER SOUTHERN MN...AND SOUTHEASTERN
CO.  HIGH DEWPOINT AIR OVER IOWA AND MISSOURI IS FEEDING A LONG LINE
OF CONVECTION OUT AHEAD OF THE FRONT...WHICH HAS BEEN MOVING VERY
SLOWLY OVER THE PAST FEW DAYS.  AT UPPER LEVELS... THE STRONG TROUGH
OVER THE ROCKIES HAS ONLY WEAK RISES BEHIND IT...INDICATING
CONTINUED SLOW MOVEMENT.  WATERVAPOR SATELLITE IMAGERY IS INDICATING
THAT A BROAD MOISTURE PLUME IS OVER THE AREA...BACKED UP BY THE 00Z
SOUNDINGS...WITH PRECIPITABLE WATERS OF OVER WELL OVER 100 PERCENT
OF NORMAL OVER A WIDE AREA...WITH PLACES NEAR THE FRONT WITH 150
PERCENT OR MORE.

PROBLEMS TODAY AGAIN ARE THE TIMING OF THE CONVECTION ENTERING THE
CWFA...SVR THREAT...AND AMOUNT OF COOLING BEHIND THE FRONT.

00Z MODELS SEEM TO HAVE INITIALIZED WELL.  ETA IS DOING RATHER
POORLY.  MID LEVELS SEEM TO BE THOUROGHLY CONVECTIVELY
CONTAMINATED...AND IT KEEPS TRYING TO PUSH THE SURFACE FRONT TO THE
NORTH...EVEN THOUGH THE LOW PRESSURE CENTER POSITIONS ARE CLOSE TO
THE NGM/AVN SOLN.  NGM AND AVN SEEM TO BE AGREEING MUCH BETTER...
THOUGH THE NGM SEEMS TO BE VERYIFYING THE BEST AT 06Z.  HAVE
FOLLOWED THE FWC FOR THE MOST PART.

THE FRONT MAKES IT THROUGH FOR THURSDAY NIGHT...AND THEN MOVES BACK
NORTH AGAIN DURING FRIDAY AS A WARM FRONT...AND REMAINS THERE FOR A
FEW MORE DAYS.  WHILE THIS SHOULD COOL THINGS OFF A LITTLE TONIGHT...
THE REGION WILL BE BACK IN THE STEAM AGAIN FOR THE WEEKEND.

LATTER PERIODS...WILL NEED TO KEEP SCATTERED POPS IN THE FORECAST
THROUGH THE WEEKEND...AS THE PATTERN IS NOT ON THE CHANGE DUE TO AN
OMEGA BLOCK OVER ALASKA.  SHORT WAVES WILL CONTINUE TO MOVE THROUGH
THE FLOW...FIRING OFF PERIODS OF SHOWERS AND THUNDERSTORMS.

AM GOING TO CONTINUE THE FLASH FLOOD WATCH FOR TODAY...AND AM GOING
TO EXTEND INTO TONIGHT...AND ADD A COUNTY FROM YESTERDAYS ISSUANCE.
FLASH FLOOD GUIDANCE VALUES FOR THOSE COUNTIES REMAINS LESS THAN AN
INCH...AND INDIVIDUAL STORMS IN THE LINE DUE TO COME THROUGH THIS
AFTERNOON/EVENING HAVE BEEN PUTTING OUT AT LEAST THAT MUCH.

.DVN...
IA...FLASH FLOOD WATCH FOR PORTIONS OF EAST AND NORTHEAST IA THIS
AFTERNOON AND TONIGHT...IAZ40>042-051>054-063.
IL...NONE.

LRE

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 10, 12:57 PM CDT	Severe Thunderstorm Warning	DVN	Keokuk	48 min
Jun 10, 1:28 PM CDT	Severe Thunderstorm Warning	DVN	Benton	32 min
Jun 10, 1:39 PM CDT	Severe Thunderstorm Warning	DVN	Iowa, Johnson	36 min
Jun 10, 1:52 PM CDT	Severe Thunderstorm Warning	DVN	Linn	33 min
Jun 10, 2:03 PM CDT	Tornado Warning	DVN	Linn	32 min
Jun 10, 2:18 PM CDT	Severe Thunderstorm Warning	DVN	Cedar	32 min
Jun 10, 2:25 PM CDT	Tornado Warning	DVN	Jones	35 min
Jun 10, 2:58 PM CDT	Severe Thunderstorm Warning	DVN	Muscatine, Scott	32 min
Jun 10, 3:20 PM CDT	Severe Thunderstorm Warning	DVN	Rock Island	35 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1999 Every severe thunderstorm warning in 1999

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.