Alert archive / Minnesota / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 95, NWS Twin Cities, MN
NWS Twin Cities, MN issued this severe thunderstorm warning at Jun 21, 1999, 6:59 PM CDT for Morrison County, Minnesota. It was in force for 31 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
- Jun 21, 1999, 6:59 PM CDT (23:59 UTC)
- Expired
- Jun 21, 1999, 7:30 PM CDT
- In force
- 31 min
- Issued by
- NWS Twin Cities, MN
- Area
- Whole counties
County Morrison County, MN
The radar
The Minneapolis radar (KMPX), 141 km from the middle of the area, began a volume at 00:04 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 |
|---|---|---|---|
| Jun 21, 7:12 PM CDT | Thunderstorm Wind 55 | Royalton, MN | Trees toppled onto power lines. |
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 12:00Z, 12.0 hours before the alert went out and 139 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1245 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 89 m²/s²
- 0-3 km storm-relative helicity
- 101 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
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 Twin Cities, MN wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 21, 2:50 PM CDT, 4 hours 9 minutes earlier.
Area forecast discussion, Jun 21, 2:50 PM CDT, 4 hours 9 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 250 PM CDT MON JUN 21 1999 FORECAST CONCERN NEAR TERM...THUNDER CHANCES. MODELS PRETTY MUCH WORTHLESS WITH THUNDERSTORM DEVELOPMENT TARGETED TO MESOSCALE. CONVECTION REDEVELOPING ALONG OLD OUTFLOW FROM EARLIER MCS OVER SOUTHEAST NODAK. THIS CONTINUES TO TRACK EAST ABOUT 30 KTS BUT SHOULD BEGIN TO DROP/DEVELOP A LITTLE MORE SOUTH OF EAST AS IT BECOMES A BIT MORE ORGANIZED...FOLLOWING MIDLEVEL THICKNESS. WILL MENTION SCATTERED THUNDER NORTHWEST CWA THIS EVENING. THEN CHANCE POPS FURTHER EAST AND SOUTH. AFTER COORD WITH DLH...WILL KEEP WESTERN WI DRY FOR NOW. DEPENDING WHAT HAPPENS WITH EVENING CONVECTION...ONLY REAL FORCING IS SOME 850MB THETA-E ADVECTION WHICH DEVELOPS DURING THE NIGHT. THIS REMAINS WEAK...BUT WITH BOUNDARIES AROUND...WHO KNOWS WHAT WILL HAPPEN. MOS TEMPERATURES APPEAR WITHIN RANGE. LATER PERIODS...MORE OF A FOCUSING MECHANISM LATER TUESDAY AS FRONT DRIVES EAST AND UPPER TROF BEGINS TO SWING INTO SOUTHWEST MINNESOTA. WILL CONTINUE CHANCE POPS MOST AREAS...WITH LIKELY POPS TUESDAY NIGHT WITH SURFACE FROPA AND 50H TROF PASSAGE. 12Z AVN HAD FRONT PUSHING WELL INTO WI BY WEDNESDAY EVENING. WILL CARRY CHANCE OF MAINLY MORNING RAIN IN EASTERN MN TUESDAY WITH POPS CONTINUING INTO WI FOR THE DAY. EXTENDED PORTION...00Z 6/21 MRF HAD FRONT ONLY IN CENTRAL MN BY THURSDAY MORNING. FEEL 12Z AVN RUN LOOKS BETTER...AND WILL KEEP THURSDAY DRY WITH FRONT WELL EAST OF AREA. COULD SEE SOMETHING DEVELOP FRIDAY NIGHT(WAA ISENTROPIC LIFT) SO WILL MENTION CHANCE OF RAIN FOR SATURDAY. TEMPERATURES LOOK OK FOR NOW. .MSP...NONE. DWE
Nearby
Severe Thunderstorm Warnings in Minnesota, 1999Every 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.