Alert archive / Montana / Tornado Watches in 2001
Tornado Watch 618
The Storm Prediction Center issued this tornado watch at Jul 23, 2001, 10:00 PM MDT for 8 counties in Montana. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 23, 2001, 10:00 PM MDT (04:00 UTC)
- Expired
- Jul 24, 2001, 3:00 AM MDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
Counties Big Horn County, MT, Carbon County, MT, Golden Valley County, MT, Musselshell County, MT, Rosebud County, MT, Stillwater County, MT, Treasure County, MT, Yellowstone County, MT
The radar
The Billings radar (KBLX), 27 km from the middle of the area, began a volume at 04:01 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.
Warnings issued inside it
1 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 23, 10:04 PM MDT | Severe Thunderstorm Warning | BYZ | Carbon, Stillwater | 56 min |
The nearest sounding before it
Great_falls, MT (KTFX), launched 00:00Z, 4.0 hours before the alert went out and 242 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
- 455 J/kg
- Mixed-layer CIN
- -4 J/kg
- Mixed-layer LCL
- 2006 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 22 m²/s²
- 0-3 km storm-relative helicity
- 30 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted, in the capitals the NWS used until 2016.
587 WWUS9 KMKC 240346 SEL8 MKC WW 240340 MTZ000-240900- URGENT - IMMEDIATE BROADCAST REQUESTED TORNADO WATCH NUMBER 618 STORM PREDICTION CENTER NORMAN OK 940 PM MDT MON JUL 23 2001 THE STORM PREDICTION CENTER HAS ISSUED A TORNADO WATCH FOR PORTIONS OF SOUTH CENTRAL MONTANA EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 1000 PM UNTIL 300 AM MDT. TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS. THE TORNADO WATCH AREA IS ALONG AND 55 STATUTE MILES NORTH AND SOUTH OF A LINE FROM 55 MILES WEST OF BILLINGS MONTANA TO 110 MILES EAST OF BILLINGS MONTANA. REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS. OTHER WATCH INFORMATION...THIS TORNADO WATCH REPLACES SEVERE THUNDERSTORM WATCH NUMBER 616. WATCH NUMBER 616 WILL NOT BE IN EFFECT AFTER 1000 PM MDT. CONTINUE...WW 617... DISCUSSION...ISOLATED SUPERCELL THUNDERSTORMS CONTINUE TO INCREASE OVER PARTS OF SOUTH CENTRAL MT NEAR BIL. THESE STORMS ARE FORECAST TO PERSIST FOR SEVERAL MORE HOURS IN REGION OF MODERATE INSTABILITY AND STRONG LOW LEVEL AND DEEP LAYER SHEAR. STRENGTHENING LOW LEVEL WINDS JUST ABOVE SURFACE AND PRESENCE OF SURFACE BOUNDARY SUGGESTED AN INCREASED THREAT OF ISOLATED TORNADOES IN STRONGER CELLS. AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION VECTOR 24035. ...HART 463,1094 463,1061 445,1061 450,1094
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 24, 4:15 PM MDT | Severe Thunderstorm Watch | SPC | Daniels, Dawson, Garfield, McCone, Petroleum, Phillips and 5 more | 6 hr |
Nearby
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.