Alert archive / Missouri / Flash Flood Warnings in 1998

Flash Flood Warning 20, NWS St. Louis, MO

July 4, 1998Knox County, Shelby County, Missouri

NWS St. Louis, MO issued this flash flood warning at Jul 4, 1998, 7:38 AM CDT for Knox County, Shelby County, Missouri. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 4, 1998, 7:38 AM CDT (12:38 UTC)
Expired
Jul 4, 1998, 10:45 AM CDT
In force
3 hr
Issued by
NWS St. Louis, MO
Area
Whole counties

Counties Knox County, MO, Shelby County, MO

The radar

The St Louis radar (KLSX), 187 km from the middle of the area, began a volume at 12:40 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, 0.6 hours before the alert went out and 229 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 1998-07-04Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 12:00Z on 1998-07-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 square meters per square second.193958Sfc1 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
853 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
-5 m²/s²
0-3 km storm-relative helicity
73 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 flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Jul 4, 6:14 AM CDT, 1 hour 24 minutes before
ILZ058>060-064-065-069-070-074-079-095>102-MOZ009-010-018-019-026-
027-034>036-041-042-047>052-059>065-072>075-084-085-099-041600-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
610 AM CDT SAT JUL 1998

THIS OUTLOOK COVERS THE COUNTY WARNING AREA OF THE NATIONAL WEATHER
SERVICE FORECAST OFFICE IN ST LOUIS.  AREAS INCLUDED ARE PORTIONS OF
NORTHEAST...CENTRAL...EAST CENTRAL AND SOUTHEAST MISSOURI AS WELL AS
WEST CENTRAL AND SOUTHWEST ILLINOIS.

THUNDERSTORMS WITH LOCALLY HEAVY RAIN WILL GRADUALLY TAPER OFF ACROSS
THE REGION THIS MORNING. SCATTERED THUNDERSTORMS MAY THEN REDEVELOP
THIS AFTERNOON.  THESE STORMS AND ANY WHICH MAY OCCUR TONIGHT ARE
NOT EXPECTED TO BECOME SEVERE.

GLASS

The office that day

Everything else NWS St. Louis, MO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 3, 11:40 PM CDTSevere Thunderstorm WarningLSXKnox65 min
Jul 4, 2:36 AM CDTFlash Flood WarningLSXMarion, Monroe, Ralls, Shelby5 hr
Jul 4, 2:36 AM CDTFlash Flood WarningLSXPike5 hr
Jul 4, 2:36 AM CDTFlash Flood WarningLSXKnox5 hr
Jul 4, 7:38 AM CDTFlash Flood WarningLSXAudrain, Monroe3 hr
Jul 4, 7:38 AM CDTFlash Flood WarningLSXKnox, Shelby3 hr
Jul 4, 7:38 AM CDTFlash Flood WarningLSXAudrain, Monroe3 hr
Jul 4, 9:02 AM CDTFlash Flood WarningLSXCallaway, Cole, Osage5 hr
Jul 4, 9:02 AM CDTFlash Flood WarningLSXBoone, Moniteau5 hr
Jul 4, 11:04 AM CDTFlash Flood WarningLSXMonroe, Shelby3 hr
Jul 4, 11:04 AM CDTFlash Flood WarningLSXAudrain3 hr

Nearby

Flash Flood Warnings in Missouri, 1998Every flash flood warning in 1998

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.