Alert archive / Minnesota / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 241, NWS Grand Forks, ND

August 15, 1999Polk County, Red Lake County, Minnesota

NWS Grand Forks, ND issued this severe thunderstorm warning at Aug 15, 1999, 10:29 PM CDT for Polk County, Red Lake County, Minnesota. It was in force for 31 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, 10:29 PM CDT (03:29 UTC)
Expired: Aug 15, 1999, 11:00 PM CDT
In force: 31 min
Issued by: NWS Grand Forks, ND
Area: Whole counties

Counties Polk County, MN, Red Lake County, MN

The radar

The Fargo/Grand Forks radar (KMVX), 87 km from the middle of the area, began a volume at 03:30 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, 11:00 PM CDT	Hail 0.88	Oklee, MN
Aug 15, 11:05 PM CDT	Hail 0.88	Gully, 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 00:00Z, 3.5 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: 2218 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 899 m above ground
0-6 km bulk shear: 63 kt
0-1 km storm-relative helicity: 32 m²/s²
0-3 km storm-relative helicity: 52 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 3.2

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, 9:00 PM CDT, 1 hour 29 minutes earlier.

Area forecast discussion, Aug 15, 9:00 PM CDT, 1 hour 29 minutes before

FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
900 PM CDT SUN AUG 15 1999

UPR LVL TROF AXIS OVR ERN MT INTO SRN AB ROTATING TO A NEG TILT. H5
UPR AIR SHOWING GOOD RISE FALL COUPLET WITH MT TROF. DRY SLOT RUNS
FM SRN CA INTO CNTRL ND. VORT MAX OVR NE MT AND ANOTHER OVR SRN AB
WITH ETA WITH A REASONABLE SOLUTION.  WATER VAPOR LOOP SHOWS SOME
RIDGE BUILDING ACRS THE THE FAR SRN CWFA HOWEVER ROTATING NEG TILT
TROF IS KNOCKING RIDGE DOWN. ETA H7 TEMPS FCST TO FALL ACRS THE CWFA
AND RELEASE THE CAP. MUCH DRIER AIR TO MOV IN AOA 600 HPA ALONG WITH
INCRG H7 WIND SPEED WL MAKE FOR POTENTIAL FOR WND DAMAGE AND FAST
MOVG STORMS. ADAP HAS MOST UNSTABLE AIR AND WEAKEST CAP OVR NE SD
AND EXTENDS N WHERE 88D HAS CURRENT LINE OF STORMS. ALSO SFC MSTR
FLUX CONVERGENCE ORIENTATED N-S WITH TSRA. PRES RISES AND MORE
STABLE AIR WERE MOVG INTO WRN ND. WL CONT TREND OF TSRA MOVG E ACRS
CWFA. WL UPDATE ZONES.

.FGF...SVR THUNDERSTORM WATCH 642 IN EFFECT UNTIL 11 PM CDT FOR ALL
ERN ND COUNTIES XCP RANSOM, SARGENT, AND RICHLAND.
HOPPES

In the hours before

Local storm report, Aug 15, 5:16 PM CDT, 5 hours 13 minutes before

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

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

0230 PM    WASKISH                   MN   1.75 INCH HAIL
08/15/99   BELTRAMI                       4E WASKISH GOLFBALL SIZE
                                          HAIL

Local storm report, Aug 15, 9:06 PM CDT, 1 hour 23 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN NORTH DAKOTA/GRAND FORKS
906 PM CDT SUN AUG 15 1999...CORRECTION FOR COUNTY

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

0855 PM    7 W LITCHVILLE            ND   TORNADO
08/15/99   BARNES                         BRIEF TOUCHDOWN IN FIELD

0903 PM    LITCHVILLE                ND   .75 INCH HAIL
08/15/99   BARNES

Local storm report, Aug 15, 9:06 PM CDT, 1 hour 23 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN NORTH DAKOTA/GRAND FORKS
906 PM CDT SUN AUG 15 1999...CORRECTION FOR COUNTY

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

0855 PM    7 W LITCHVILLE            ND   TORNADO
08/15/99   BARNES                         BRIEF TOUCHDOWN IN FIELD

0903 PM    LITCHVILLE                ND   .75 INCH HAIL
08/15/99   BARNES

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 15, 7:22 PM CDT	Severe Thunderstorm Warning	FGF	Benson	48 min
Aug 15, 8:10 PM CDT	Severe Thunderstorm Warning	FGF	Eddy	35 min
Aug 15, 8:41 PM CDT	Tornado Warning	FGF	Barnes	49 min
Aug 15, 9:11 PM CDT	Tornado Warning	FGF	Barnes, Ransom	49 min
Aug 15, 9:40 PM CDT	Tornado Warning	FGF	Ransom	35 min
Aug 15, 10:58 PM CDT	Severe Thunderstorm Warning	FGF	Pennington, Polk, Red Lake	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.