Alert archive / Minnesota / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 238, NWS Grand Forks, ND

August 15, 1999Marshall County, Polk County, Minnesota

NWS Grand Forks, ND issued this severe thunderstorm warning at Aug 15, 1999, 2:04 PM CDT for Marshall County, Polk County, Minnesota. It was in force for 36 min. 2 reports 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: Aug 15, 1999, 2:04 PM CDT (19:04 UTC)
Expired: Aug 15, 1999, 2:40 PM CDT
In force: 36 min
Issued by: NWS Grand Forks, ND
Area: Whole counties

Counties Marshall County, MN, Polk County, MN

The radar

The Fargo/Grand Forks radar (KMVX), 92 km from the middle of the area, began a volume at 19:22 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

Time	Report	Where	Remark
Aug 15, 2:15 PM CDT	Hail 1.25	Warren, MN
Aug 15, 2:30 PM CDT	Hail 1	Angus, 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 nearest sounding before it

Bismarck Municip, ND (KBIS), launched 12:00Z, 7.1 hours before the alert went out and 355 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: 1866 J/kg
Mixed-layer CIN: -269 J/kg
Mixed-layer LCL: 690 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: -39 m²/s²
0-3 km storm-relative helicity: 113 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.8

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 Grand Forks, ND wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 15, 10:20 AM CDT, 3 hours 44 minutes earlier.

Area forecast discussion, Aug 15, 10:20 AM CDT, 3 hours 44 minutes before

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In the hours before

Local storm report, Aug 15, 11:48 AM CDT, 2 hours 16 minutes before

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    <section class="card" role="status" aria-live="polite">
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Local storm report, Aug 15, 1:39 PM CDT, 25 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN NORTH DAKOTA/GRAND FORKS
139 PM CDT SUN AUG 15 1999

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0100 PM    6 SW LANKIN               ND   .75 INCH HAIL
08/15/99   WALSH                          DIME SIZE HAIL

The office that day

Everything else NWS Grand Forks, ND issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 15, 11:08 AM CDT	Severe Thunderstorm Warning	FGF	Pembina, Walsh	32 min
Aug 15, 11:55 AM CDT	Severe Thunderstorm Warning	FGF	Walsh	35 min
Aug 15, 12:30 PM CDT	Severe Thunderstorm Warning	FGF	Walsh	35 min
Aug 15, 12:55 PM CDT	Severe Thunderstorm Warning	FGF	Walsh	35 min
Aug 15, 1:58 PM CDT	Severe Thunderstorm Warning	FGF	Beltrami	32 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.