Alert archive / Minnesota / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 39, NWS La Crosse, WI

June 6, 1999Fillmore County, Minnesota; Howard County, Iowa

NWS La Crosse, WI issued this severe thunderstorm warning at Jun 6, 1999, 5:31 PM CDT for Fillmore County, Minnesota; Howard County, Iowa. It was in force for 64 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
Jun 6, 1999, 5:31 PM CDT (22:31 UTC)
Expired
Jun 6, 1999, 6:35 PM CDT
In force
64 min
Issued by
NWS La Crosse, WI
Area
Whole counties

Counties Howard County, IA, Fillmore County, MN

The radar

The La Crosse radar (KARX), 88 km from the middle of the area, began a volume at 22:31 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
Jun 6, 6:19 PM CDTThunderstorm Wind 52Preston, MN

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 watch it was issued in

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

IssuedProductOfficeLasted
Jun 6, 12:45 PM CDTSevere Thunderstorm WatchSPC5 hr
Jun 6, 5:15 PM CDTTornado WatchSPC7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 10.5 hours before the alert went out and 186 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, Minneapolis, MN at 12:00Z on 1999-06-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1851 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, Minneapolis, MN at 12:00Z on 1999-06-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 283 square meters per square second.1939587897117Sfc1 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
1851 J/kg
Mixed-layer CIN
-82 J/kg
Mixed-layer LCL
752 m above ground
0-6 km bulk shear
72 kt
0-1 km storm-relative helicity
283 m²/s²
0-3 km storm-relative helicity
338 m²/s²
Significant tornado parameter
2.7
Supercell composite
9.4

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KLSE 062233 RRA
SVRLSE
IAC089-MNC045-062335-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
531 PM CDT SUN JUN 6 1999

THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  FILLMORE COUNTY IN SOUTHEASTERN MINNESOTA
  HOWARD COUNTY IN NORTHEASTERN IOWA

* UNTIL 635 PM CDT

* AT 527 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS 20 MILES SOUTHEAST OF ROCHESTER TO 30
  MILES EAST OF MASON CITY... MOVING NORTHEAST AT 40 MPH.

* THIS LINE OF SEVERE THUNDERSTORMS WILL BE NEAR...
  SARATOGA IOWA BY 535 PM
  SPRING VALLEY MINNESOTA BY 545 PM
  CHESTER IOWA BY 540 PM

THE MAIN THREAT FROM THESE STORMS IS DAMAGING WIND. STAY INSIDE
AND AWAY FROM WINDOWS! A TORNADO WATCH IS IN EFFECT FOR FILLMORE
COUNTY UNTIL MIDNIGHT. SEVERE THUNDERSTORMS CAN AND DO OCCASIONALLY
PRODUCE TORNADOS WITH LITTLE WARNING.

NELSON/RIECK\

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 La Crosse, WI wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 6, 2:56 PM CDT, 2 hours 35 minutes earlier.

Area forecast discussion, Jun 6, 2:56 PM CDT, 2 hours 35 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
252 PM CDT SUN JUNE 6 1999

MAIN FOCUS AGAIN THIS AFTERNOON AND EVENING IS SEVERE WEATHER
POTENTIAL.  SVR AND TOR WATCHES IN EFFECT FOR ENTIRE CWA EXCEPT FOR
TAYLOR COUNTY THROUGH THIS EVENING.  GIVEN INCREASING LINEAR SPEED
SHEAR DUE TO H3 JET NOSING INTO CENTRAL IOWA...EXPECT AN ACTIVE
EVENING ON THE RADAR.

THE GOOD NEWS IS THAT ALL MODELS ADVERTISE RIDGING AND GOOD DRYING
AFTER MIDNIGHT AS THE VIGOROUS SHORTWAVE AND UPPER TROF MOVE
NORTHEASTWARD OVERNIGHT AND MONDAY.

MAIN CONCERNS BEYOND TONIGHT FOCUS ON MAX TEMPERATURES NEXT TWO
DAYS.  EVEN WITH HEIGHTS SOMEWHAT DEPRESSED ON MONDAY...850 TEMPS
REMAIN WARM AND GIVEN THE DRYING OCCURRING IN THE LOW LEVELS AND
GOOD MIXING...EXPECT LITTLE COOLING FROM TODAY'S READINGS.  RIDGE
AMPLIFIES ON TUESDAY FOR WARMER CONDITIONS...PROBABLY WELL INTO THE
LOWER TO MIDDLE 90S OVER SOUTHWEST WISCONSIN.

.LSE...NONE.

DEVOIR

In the hours before

Special weather statement, Jun 6, 12:10 PM CDT, 5 hours 21 minutes before
IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-
032>034-041>044-053>055-061-070000-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LA CROSSE WI
1210 PM CDT SUN JUN 6 1999

...MODERATE RISK FOR SEVERE THUNDERSTORMS ACROSS SOUTHEAST
MINNESOTA...NORTHEAST IOWA...AND WESTERN AND CENTRAL WISCONSIN THIS
AFTERNOON AND EVENING...

A VERY MOIST AND UNSTABLE AIR MASS WAS LOCATED OVER THE UPPER
MISSISSIPPI VALLEY THIS AFTERNOON...WITH SOME CONVECTION ALREADY
DEVELOPING. A LINE OF SURFACE CONVERGENCE OVER WESTERN MN WILL MOVE
EAST AS THE AFTERNOON WEARS ON...PROVIDING MORE OF A FOCUS FOR
THUNDERSTORM DEVELOPMENT. WITH THE ATMOSPHERE SO UNSTABLE AND LINGERING
BOUNDARIES FROM EARLY MORNING SHOWERS AND STORMS...STORMS COULD STILL
DEVELOP ALMOST ANYWHERE ACROSS THE AREA. FOR TONIGHT...A DISTURBANCE
ALOFT WILL COUPLE WITH A COLD FRONT PUSHING IN FROM THE
PLAINS...PROVIDING ANOTHER FOCUS FOR POSSIBLE SEVERE THUNDERSTORMS.

THE MAIN SEVERE THREAT WILL BE DAMAGING WINDS AND LARGE HAIL. TRAINING
THUNDERSTORMS WILL ALSO BE POSSIBLE...WHICH COULD CAUSE FLOODING
PROBLEMS TO MANY ALREADY SATURATED LOCATIONS.

SPOTTER GROUPS SHOULD REMAIN ALERT FOR POSSIBLE ACTIVATION THIS
AFTERNOON AND EVENING.

RIECK
Special weather statement, Jun 6, 12:10 PM CDT, 5 hours 21 minutes before
IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-
032>034-041>044-053>055-061-070000-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LA CROSSE WI
1210 PM CDT SUN JUN 6 1999

...MODERATE RISK FOR SEVERE THUNDERSTORMS ACROSS SOUTHEAST
MINNESOTA...NORTHEAST IOWA...AND WESTERN AND CENTRAL WISCONSIN THIS
AFTERNOON AND EVENING...

A VERY MOIST AND UNSTABLE AIR MASS WAS LOCATED OVER THE UPPER
MISSISSIPPI VALLEY THIS AFTERNOON...WITH SOME CONVECTION ALREADY
DEVELOPING. A LINE OF SURFACE CONVERGENCE OVER WESTERN MN WILL MOVE
EAST AS THE AFTERNOON WEARS ON...PROVIDING MORE OF A FOCUS FOR
THUNDERSTORM DEVELOPMENT. WITH THE ATMOSPHERE SO UNSTABLE AND LINGERING
BOUNDARIES FROM EARLY MORNING SHOWERS AND STORMS...STORMS COULD STILL
DEVELOP ALMOST ANYWHERE ACROSS THE AREA. FOR TONIGHT...A DISTURBANCE
ALOFT WILL COUPLE WITH A COLD FRONT PUSHING IN FROM THE
PLAINS...PROVIDING ANOTHER FOCUS FOR POSSIBLE SEVERE THUNDERSTORMS.

THE MAIN SEVERE THREAT WILL BE DAMAGING WINDS AND LARGE HAIL. TRAINING
THUNDERSTORMS WILL ALSO BE POSSIBLE...WHICH COULD CAUSE FLOODING
PROBLEMS TO MANY ALREADY SATURATED LOCATIONS.

SPOTTER GROUPS SHOULD REMAIN ALERT FOR POSSIBLE ACTIVATION THIS
AFTERNOON AND EVENING.

RIECK

The office that day

Everything else NWS La Crosse, WI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 5, 8:58 PM CDTSevere Thunderstorm WarningARXDodge, Mower62 min
Jun 5, 9:25 PM CDTSevere Thunderstorm WarningARXOlmsted65 min
Jun 5, 9:28 PM CDTSevere Thunderstorm WarningARXWabasha47 min
Jun 5, 9:52 PM CDTSevere Thunderstorm WarningARXWinona68 min
Jun 5, 9:55 PM CDTSevere Thunderstorm WarningARXFillmore, Mower65 min
Jun 5, 10:52 PM CDTSevere Thunderstorm WarningARXFillmore53 min
Jun 5, 11:08 PM CDTSevere Thunderstorm WarningARXWinona62 min
Jun 5, 11:27 PM CDTSevere Thunderstorm WarningARXHouston63 min
Jun 6, 12:44 AM CDTSevere Thunderstorm WarningARXWabasha46 min
Jun 6, 5:12 PM CDTSevere Thunderstorm WarningARXMower63 min
Jun 6, 5:21 PM CDTSevere Thunderstorm WarningARXDodge, Olmsted64 min
Jun 6, 5:48 PM CDTSevere Thunderstorm WarningARXWabasha, Winona62 min
Jun 5, 9:24 PM CDTSevere Thunderstorm WarningARXMitchell36 min
Jun 6, 4:51 PM CDTSevere Thunderstorm WarningARXFloyd, Mitchell59 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 1999Severe Thunderstorm Warnings in Iowa, 1999Every 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.