Alert archive / Minnesota / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 170, NWS Twin Cities, MN

July 20, 2002Mille Lacs County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Jul 20, 2002, 11:07 PM CDT for Mille Lacs County, Minnesota. It was in force for 38 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 20, 2002, 11:07 PM CDT (04:07 UTC)
Expired
Jul 20, 2002, 11:45 PM CDT
In force
38 min
Issued by
NWS Twin Cities, MN
Area
Counties, with a storm outline in the text

County Mille Lacs County, MN

The radar

The Duluth radar (KDLH), 133 km from the middle of the area, began a volume at 04:06 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
Jul 20, 11:35 PM CDTThunderstorm Wind 55 EIsle, MNTrees down, including one on a trailer.

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 nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 4.1 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-pSkew-T log-p diagram, Minneapolis, MN at 00:00Z on 2002-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4791 joules per kilogram.LCLLFCEL10008507005003002001001 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, Minneapolis, MN at 00:00Z on 2002-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 269 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
4791 J/kg
Mixed-layer CIN
-73 J/kg
Mixed-layer LCL
842 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
269 m²/s²
0-3 km storm-relative helicity
412 m²/s²
Significant tornado parameter
7.4
Supercell composite
49.7

Open this sounding in Storm Lab

The text

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

946 
WUUS53 KMPX 210407
SVRMSP
MNC095-210445-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1106 PM CDT SAT JUL 20 2002

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  MILLE LACS COUNTY IN EAST CENTRAL MINNESOTA

* UNTIL 1145 PM CDT

* AT 1106 PM CDT...RADAR INDICATED A SEVERE THUNDERSTORM WITH LARGE
  HAIL 15 MILES WEST OF WAHKON...OR ABOUT 21 MILES SOUTHEAST OF
  BRAINERD...MOVING EAST AT 25 MPH.

* SOME LOCATIONS AFFECTED BY THIS STORM INCLUDE...
  WAHKON
  VINELAND
  ONAMIA.

THIS IS A DANGEROUS STORM...STAY INDOORS AWAY FROM WINDOWS. SEVERE
THUNDERSTORMS CAN PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE
WARNING.

LAT...LON 4623 9396 4624 9370 4609 9368 4608 9347
          4658 9352

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 21, 7:04 AM CDTSevere Thunderstorm WarningMPXDouglas, Pope, Todd41 min
Jul 21, 7:32 AM CDTSevere Thunderstorm WarningMPXMorrison58 min
Jul 21, 7:45 AM CDTSevere Thunderstorm WarningMPXTodd30 min
Jul 21, 2:53 PM CDTFlash Flood WarningMPXAnoka, Hennepin, Wright3 hr
Jul 21, 5:00 PM CDTSevere Thunderstorm WarningMPXFreeborn45 min
Jul 21, 5:32 PM CDTSevere Thunderstorm WarningMPXMartin43 min
Jul 21, 5:48 PM CDTFlash Flood WarningMPXFreeborn3 hr
Jul 21, 6:00 PM CDTFlash Flood WarningMPXFaribault, Martin3 hr
Jul 21, 6:20 PM CDTSevere Thunderstorm WarningMPXFaribault, Martin40 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 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.