Alert archive / Montana / Severe Thunderstorm Watches in 2014

Severe Thunderstorm Watch 437

July 23, 201419 counties in Montana

The Storm Prediction Center issued this severe thunderstorm watch at Jul 23, 2014, 8:31 PM MDT for 19 counties in Montana. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jul 23, 2014, 8:31 PM MDT (02:31 UTC)
Expired
Jul 24, 2014, 3:00 AM MDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
65 kt

Counties Blaine County, MT, Broadwater County, MT, Cascade County, MT, Chouteau County, MT, Fergus County, MT, Garfield County, MT, Glacier County, MT, Hill County, MT, Jefferson County, MT, Judith Basin County, MT, Lewis and Clark County, MT, Liberty County, MT, Meagher County, MT, Petroleum County, MT, Phillips County, MT, Pondera County, MT, Teton County, MT, Toole County, MT, Valley County, MT

The radar

The Great Falls radar (KTFX), 125 km from the middle of the area, began a volume at 02:35 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
30%
One or more gusts of 65 knots or more
30%
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
60%

Warnings issued inside it

15 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jul 23, 9:30 PM MDTSevere Thunderstorm WarningGGWPhillips15 min
Jul 23, 10:27 PM MDTSevere Thunderstorm WarningTFXFergus, Judith Basin48 min
Jul 23, 10:40 PM MDTSevere Thunderstorm WarningTFXBlaine50 min
Jul 23, 10:49 PM MDTSevere Thunderstorm WarningGGWPhillips46 min
Jul 23, 11:06 PM MDTSevere Thunderstorm WarningGGWPhillips, Valley14 min
Jul 23, 11:28 PM MDTSevere Thunderstorm WarningTFXBlaine47 min
Jul 24, 12:11 AM MDTSevere Thunderstorm WarningGGWPhillips64 min
Jul 24, 12:14 AM MDTSevere Thunderstorm WarningTFXBlaine46 min
Jul 24, 1:25 AM MDTSevere Thunderstorm WarningGGWGarfield65 min
Jul 24, 1:35 AM MDTSevere Thunderstorm WarningGGWPhillips, Valley55 min
Jul 24, 2:09 AM MDTSevere Thunderstorm WarningGGWGarfield44 min
Jul 24, 2:13 AM MDTSevere Thunderstorm WarningGGWDaniels, Valley62 min
Jul 24, 2:23 AM MDTSevere Thunderstorm WarningGGWGarfield, McCone67 min
Jul 24, 2:36 AM MDTSevere Thunderstorm WarningGGWDawson, Garfield, McCone, Prairie54 min
Jul 24, 2:42 AM MDTSevere Thunderstorm WarningGGWDaniels, Roosevelt, Valley63 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 00:00Z, 2.5 hours before the alert went out and 87 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-pSkew-T log-p diagram, Great_falls, MT at 00:00Z on 2014-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 773 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Great_falls, MT at 00:00Z on 2014-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 44 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
773 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
2874 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
44 m²/s²
0-3 km storm-relative helicity
98 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.8

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 23, 6:58 PM MDTMesoscale DiscussionSPCFlathead, Granite, Lake, Lincoln, Mineral, Missoula and 2 more92 min
Jul 23, 7:52 PM MDTMesoscale DiscussionSPCBlaine, Cascade, Chouteau, Fergus, Garfield, Golden Valley and 12 more113 min
Jul 23, 8:28 PM MDTMesoscale DiscussionSPCCarter, Custer, Fallon, Powder River92 min
Jul 23, 10:52 PM MDTMesoscale DiscussionSPCCarter, Custer, Fallon, Powder River83 min
Jul 24, 1:41 AM MDTMesoscale DiscussionSPCDaniels, Garfield, McCone, Phillips, Richland, Roosevelt and 2 more2 hr
Jul 24, 2:27 AM MDTSevere Thunderstorm WatchSPCDaniels, Dawson, McCone, Prairie, Richland, Roosevelt and 2 more6 hr
Jul 24, 1:50 PM MDTMesoscale DiscussionSPCBlaine, Daniels, Dawson, Fergus, Garfield, Hill and 7 more55 min
Jul 24, 2:54 PM MDTSevere Thunderstorm WatchSPCDaniels, Dawson, Garfield, McCone, Phillips, Richland and 4 more6 hr
Jul 24, 3:07 PM MDTMesoscale DiscussionSPCBig Horn, Carter, Custer, Fallon, Powder River, Rosebud and 1 more53 min
Jul 24, 4:53 PM MDTMesoscale DiscussionSPCCarter, Custer, Daniels, Dawson, Fallon, Garfield and 9 more97 min

Nearby

Severe Thunderstorm Watches in Montana, 2014Every severe thunderstorm watch in 2014

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.