Alert archive / Montana / Severe Thunderstorm Watches in 2013
Severe Thunderstorm Watch 396
The Storm Prediction Center issued this severe thunderstorm watch at Jul 7, 2013, 4:00 PM MDT for 28 counties in Montana; 10 counties in Wyoming. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 7, 2013, 4:00 PM MDT (22:00 UTC)
- Expired
- Jul 7, 2013, 11:00 PM MDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 38 counties
Beaverhead County, MT, Big Horn County, MT, Broadwater County, MT, Carbon County, MT, Carter County, MT, Cascade County, MT, Custer County, MT, Fallon County, MT, Fergus County, MT, Gallatin County, MT, Garfield County, MT, Golden Valley County, MT, Jefferson County, MT, Judith Basin County, MT, Lewis and Clark County, MT, Madison County, MT, Meagher County, MT, Musselshell County, MT, Park County, MT, Petroleum County, MT, Powder River County, MT, Prairie County, MT, Rosebud County, MT, Stillwater County, MT, Sweet Grass County, MT, Treasure County, MT, Wheatland County, MT, Yellowstone County, MT, Big Horn County, WY, Campbell County, WY, Crook County, WY, Hot Springs County, WY, Johnson County, WY, Park County, WY, Sheridan County, WY, Teton County, WY, Washakie County, WY, Weston County, WY
The radar
The Billings radar (KBLX), 24 km from the middle of the area, began a volume at 22:03 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 SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 10%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
16 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 7, 4:14 PM MDT | Severe Thunderstorm Warning | BYZ | Big Horn | 61 min |
| Jul 7, 4:44 PM MDT | Severe Thunderstorm Warning | UNR | Crook | 61 min |
| Jul 7, 4:57 PM MDT | Tornado Warning | UNR | Crook | 48 min |
| Jul 7, 5:04 PM MDT | Severe Thunderstorm Warning | TFX | Fergus, Judith Basin | 41 min |
| Jul 7, 5:16 PM MDT | Severe Thunderstorm Warning | BYZ | Big Horn | 59 min |
| Jul 7, 5:34 PM MDT | Severe Thunderstorm Warning | TFX | Broadwater, Jefferson | 41 min |
| Jul 7, 5:38 PM MDT | Severe Thunderstorm Warning | UNR | Crook | 67 min |
| Jul 7, 5:56 PM MDT | Severe Thunderstorm Warning | BYZ | Golden Valley, Wheatland | 64 min |
| Jul 7, 6:08 PM MDT | Severe Thunderstorm Warning | BYZ | Big Horn, Powder River, Rosebud | 37 min |
| Jul 7, 6:23 PM MDT | Severe Thunderstorm Warning | BYZ | Sheridan | 37 min |
| Jul 7, 6:25 PM MDT | Severe Thunderstorm Warning | UNR | Campbell | 65 min |
| Jul 7, 6:30 PM MDT | Severe Thunderstorm Warning | UNR | Crook | 60 min |
| Jul 7, 7:26 PM MDT | Severe Thunderstorm Warning | UNR | Campbell, Crook | 64 min |
| Jul 7, 8:08 PM MDT | Severe Thunderstorm Warning | UNR | Crook | 67 min |
| Jul 7, 8:13 PM MDT | Severe Thunderstorm Warning | UNR | Campbell | 62 min |
| Jul 7, 9:37 PM MDT | Severe Thunderstorm Warning | UNR | Crook, Weston | 53 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Great_falls, MT (KTFX), launched 12:00Z, 10.0 hours before the alert went out and 212 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
- 5 J/kg
- Mixed-layer CIN
- -273 J/kg
- Mixed-layer LCL
- 791 m above ground
- 0-6 km bulk shear
- 43 kt
- 0-1 km storm-relative helicity
- 41 m²/s²
- 0-3 km storm-relative helicity
- 201 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 7, 2:47 PM MDT | Mesoscale Discussion | SPC | Big Horn, Carbon, Park, Rosebud, Stillwater, Sweet Grass and 2 more | 58 min |
| Jul 7, 4:12 PM MDT | Mesoscale Discussion | SPC | Goshen, Laramie, Niobrara | 2 hr |
Nearby
Severe Thunderstorm Watches in Montana, 2013Severe Thunderstorm Watches in Wyoming, 2013Every severe thunderstorm watch in 2013
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.