Alert archive / Minnesota / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 138, NWS Grand Forks, ND

July 12, 1999Polk County, Minnesota

NWS Grand Forks, ND issued this severe thunderstorm warning at Jul 12, 1999, 11:14 PM CDT for Polk County, Minnesota. It was in force for 36 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: Jul 12, 1999, 11:14 PM CDT (04:14 UTC)
Expired: Jul 12, 1999, 11:50 PM CDT
In force: 36 min
Issued by: NWS Grand Forks, ND
Area: Whole counties

County Polk County, MN

The radar

The Fargo/Grand Forks radar (KMVX), 74 km from the middle of the area, began a volume at 04:15 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
Jul 12, 11:20 PM CDT	Hail 1	Euclid, 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.

Issued	Product	Office	Lasted
Jul 12, 8:00 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Bismarck Municip, ND (KBIS), launched 00:00Z, 4.2 hours before the alert went out and 343 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: 1355 J/kg
Mixed-layer CIN: -48 J/kg
Mixed-layer LCL: 2177 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 76 m²/s²
0-3 km storm-relative helicity: 116 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.7

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 Jul 12, 7:50 PM CDT, 3 hours 24 minutes earlier.

Area forecast discussion, Jul 12, 7:50 PM CDT, 3 hours 24 minutes before

FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
750 PM CDT MON JUL 12 1999

SEVERE THUNDERSTORM WATCH COORDINATED WITH SPS. MULTIPLE SUPERCELLS NOR
DROPPING SEWD INTO NORTHEAST ND...INTO VERY UNSTABLE AIRMASS WITH CAPES
APPCHG 4K AND LIS MINUS 8 TO MINUS 10 IN NRN PORTIONS OF THE RRV WHERE
DEWPTS ARE HOVERING AROUND 70 DEGREES. SFC TROF SAGGING INTO AREA HAS
BEEN GOOD FOCUS POINT AND CONVECTION LIKELY TO SAG SOUTH AND THEN PUSH
ACROSS EWD.

.FGF...SVR TSTM WATCH NORTHEAST NORTH DAKOTA AND NORTHWEST MINNESOTA
UNTIL 1AM CDT.

GUST

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 12, 8:02 PM CDT	Severe Thunderstorm Warning	FGF	Cavalier, Towner	48 min
Jul 12, 8:48 PM CDT	Severe Thunderstorm Warning	FGF	Cavalier	32 min
Jul 12, 9:18 PM CDT	Tornado Warning	FGF	Traill	32 min
Jul 12, 9:21 PM CDT	Tornado Warning	FGF	Ramsey, Walsh	34 min
Jul 12, 9:56 PM CDT	Tornado Warning	FGF	Ramsey, Walsh	34 min
Jul 12, 10:23 PM CDT	Severe Thunderstorm Warning	FGF	Nelson	32 min
Jul 12, 10:52 PM CDT	Severe Thunderstorm Warning	FGF	Nelson	33 min
Jul 12, 11:24 PM CDT	Severe Thunderstorm Warning	FGF	Grand Forks	36 min
Jul 12, 10:43 PM CDT	Severe Thunderstorm Warning	FGF	Polk	32 min
Jul 13, 12:29 AM CDT	Severe Thunderstorm Warning	FGF	Norman	36 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.