Alert archive / Minnesota / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 122, NWS Twin Cities, MN

July 8, 1999Stevens County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Jul 8, 1999, 4:22 AM CDT for Stevens County, Minnesota. It was in force for 38 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: Jul 8, 1999, 4:22 AM CDT (09:22 UTC)
Expired: Jul 8, 1999, 5:00 AM CDT
In force: 38 min
Issued by: NWS Twin Cities, MN
Area: Whole counties

County Stevens County, MN

The radar

The Aberdeen radar (KABR), 189 km from the middle of the area, began a volume at 09:23 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

Aberdeen, SD (KABR), launched 00:00Z, 9.4 hours before the alert went out and 203 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: 22 J/kg
Mixed-layer CIN: -361 J/kg
Mixed-layer LCL: 2040 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: -4 m²/s²
0-3 km storm-relative helicity: 137 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMPX 080924 RRA
SVRMSP
MNC149-081000-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES-CHANHASSEN MN
422 AM CDT THU JUL 8 1999

THE NATIONAL WEATHER SERVICE IN TWIN CITIES-CHANHASSEN MN HAS ISSUED
A

* SEVERE THUNDERSTORM WARNING FOR...
  STEVENS COUNTY IN WEST CENTRAL MINNESOTA

* UNTIL 500 AM CDT

* AT 422 AM CDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM WITH LARGE HAIL AND DAMAGING WINDS 6 MILES
  NORTH OF CHOKIO...OR ABOUT 12 MILES WEST OF MORRIS...MOVING EAST AT
  55 MPH.

* SOME LOCATIONS AFFECTED BY THIS STORM INCLUDE...
  MORRIS
  HANCOCK
  DONNELLY
  CHOKIO
  ALBERTA

LARGE HAIL AND DAMAGING WINDS ARE LIKELY WIXTH THIS STORM. TAKE COVER
IN A STURDY BUILDING AND STAY AWAY FROM WINDOWS.

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 Twin Cities, MN wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 8, 3:30 AM CDT, 52 minutes earlier.

Area forecast discussion, Jul 8, 3:30 AM CDT, 52 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
330 AM CDT THU JUL 8 1999

MCS HAS PROPAGATED INTO W CENTRAL MN THIS MORNING...EXPECT COMPLEX
TO TRACK ALONG 850-500MB THICKNESS LINES...BUT WEAKEN IN MORE STABLE
AIR TO EAST AND SOUTH.  850 MB WARM FRONT WILL ALSO BE FOCUS OF
CONVECTION THIS MORNING...BUT SHOULD MOVE TO NRN PORTIONS OF FORECAST
AREA BY NOON...WITH LOW LEVEL THETA-E GRADIENT/HIGH PRECIPITABLE
WATER...HEAVY RAIN POSSIBLE.  MODELS DIFFER ON TRACK OF SURFACE
LOW...BUT ALL TEND TO PULL LOW NORTHWARD IN RESPONSE TO RIGHT
ENTRANCE OF UPPER JET OVER ONT/GREAT LAKES.  PREFER 03Z ETA
TRACK...ESPECIALLY IN LIGHT OF CURRENT SURFACE PRESSURE FALL
PATTERN.  COOL FRONT/DRY LINE SHOULD PUSH THROUGH AREA THIS
AFTERNOON.  SUFFICIENT INSTABILITY ALONG WITH STRONG SHEAR FOR RISK
OF SEVERE STORMS IN WARM SECTOR...HEATING AND MODIFICATIONS BY MCS
KEY HERE...BUT WILL MENTION SEVERE ACROSS AREA PER SPC DISCUSSION.
THUNDERSTORMS INTO EARLY EVENING ERN PORTIONS.  COOLER AIR ALOFT ON
FRIDAY...WITH SCATTERED INSTABILITY SHOWERS POSSIBLE NRN PORTIONS OF
FORECAST AREA.

.MSP...NONE.
 SCOTT

The office that day

Everything else NWS Twin Cities, MN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 8, 7:00 AM CDT	Severe Thunderstorm Warning	MPX	Blue Earth, Nicollet	45 min
Jul 8, 7:42 AM CDT	Severe Thunderstorm Warning	MPX	Le Sueur	33 min
Jul 8, 5:26 PM CDT	Severe Thunderstorm Warning	MPX	Goodhue	34 min
Jul 8, 6:54 PM CDT	Severe Thunderstorm Warning	MPX	Freeborn, Steele	51 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 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.