Alert archive / Montana / Special Weather Statements in 2021
Special Weather Statement, NWS Missoula, MT
NWS Missoula, MT issued this special weather statement at Jul 7, 2021, 8:42 AM MDT. It was in force for 48 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Jul 7, 2021, 8:42 AM MDT (14:42 UTC)
- Expired
- Jul 7, 2021, 9:30 AM MDT
- In force
- 48 min
- Issued by
- NWS Missoula, MT
The radar
The Missoula radar (KMSX), 67 km from the middle of the area, began a volume at 14:44 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.
The nearest sounding before it
Spokane, WA (KOTX), launched 12:00Z, 2.7 hours before the alert went out and 188 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
- 3750 m above ground
- 0-6 km bulk shear
- 43 kt
- 0-1 km storm-relative helicity
- -24 m²/s²
- 0-3 km storm-relative helicity
- -18 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
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</html>What forecasters said that day
The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Missoula, MT wrote its last area forecast discussion before this special weather statement went out at Jul 7, 3:07 AM MDT, 5 hours 35 minutes earlier.
Area forecast discussion, Jul 7, 3:07 AM MDT, 5 hours 35 minutes before
Area Forecast Discussion National Weather Service Missoula MT 307 AM MDT Wed Jul 7 2021 ...THUNDERSTORMS THIS AFTERNOON... .DISCUSSION...A plume of moisture is moving into the region ahead of the upcoming shortwave trough and cold front. Atmospheric moisture today will be around 150 percent of normal, that along with continued heat, and a cold front passage, is a good setup up for showers and thunderstorms. Radar projections show showers moving into north-central Idaho this morning followed by a few thunderstorms with the cold front this afternoon. Showers are also projected to move through western Montana and Lemhi County during this morning before widespread thunderstorms develop this afternoon. All of the convection- allowing models are showing an early start to thunderstorms with the peak thunderstorm period being between 2 pm and 5 pm MDT, but the first storms initiate around noon. If you have anything that is susceptible to damage from wind or hail, this morning is a good time to move or protect them. The majority of the convection-allowing models show thunderstorms from Lost Trail Pass through Georgetown Lake, Anaconda, Deer Lodge. Butte and south through Dillon. Surface conditions are also fairly dry in the aforementioned locations, so gusty, and potentially damaging winds are expected. Another round of storms may pass through northwest Montana and along the Divide during the evening, otherwise, a quick clear-out is expected. Drier air moves in behind the cold front on Thursday, leading to storm-free, and slightly cooler conditions. Model guidance continues to show a shortwave trough moving through the region on Friday, but are all very pessimistic when it comes to precipitation chances. One reason for limited showers could be the entrainment of drier air from Oregon, but showers cannot be ruled out during Friday morning. Consistency remains for high pressure to strengthen and bring hot temperatures back for the weekend, followed by a slightly cooler to start next week. && .AVIATION...Showers will continue to expand into north-central Idaho and western Montana, within a moisture plume, ahead of a shortwave trough and cold front. The convection-allowing models agree on most of the thunderstorms occurring in western Montana during this afternoon, with initiation around 07/1800z. The peak thunderstorm period is projected to be between 07/2000z-07/2300z. The strongest storms, which may produce over 50-knot winds will be between Lost Trail Pass through Georgetown Lake, Anaconda, Deer Lodge. Butte and south through Dillon. Storms may linger along the Divide into the evening, but drier air will quickly put an end to storms in most places after 08/0000z. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...&&
In the hours before
Special weather statement, Jul 7, 8:33 AM MDT, 9 minutes before
Special Weather Statement National Weather Service Missoula MT 833 AM MDT Wed Jul 7 2021 MTZ001-003-004-071515- Flathead/Mission Valleys MT-Lower Clark Fork Region MT- Kootenai/Cabinet Region MT- 833 AM MDT Wed Jul 7 2021 ...SIGNIFICANT WEATHER ADVISORY FOR NORTH CENTRAL MINERAL... NORTHWESTERN MISSOULA AND SOUTHEASTERN SANDERS COUNTIES UNTIL 915 AM MDT... At 832 AM MDT, Doppler radar was tracking a strong thunderstorm near St. Regis, or 7 miles northwest of Superior, moving northeast at 45 mph. Locations impacted include... Superior, Plains, St. Regis, Paradise, Camas Prairie, Keystone, Weeksville and Perma. PRECAUTIONARY/PREPAREDNESS ACTIONS... Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. && LAT...LON 4713 11504 4731 11529 4768 11481 4741 11442 TIME...MOT...LOC 1432Z 231DEG 40KT 4726 11503
Special weather statement, Jul 7, 8:42 AM MDT, 0 minutes before
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<h1 id="headline">This service is currently unavailable.</h1>
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The site you requested is temporarily down for maintenance or an unexpected outage.
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Please try again in a few minutes.
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</html>The office that day
Everything else NWS Missoula, MT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 7, 8:33 AM MDT | Special Weather Statement | MSO | Mineral | 42 min |
| Jul 7, 12:56 PM MDT | Special Weather Statement | MSO | Ravalli | 49 min |
| Jul 7, 2:18 PM MDT | Special Weather Statement | MSO | Deer Lodge, Granite, Powell | 42 min |
| Jul 7, 2:45 PM MDT | Severe Thunderstorm Warning | MSO | Deer Lodge, Granite, Powell, Silver Bow | 30 min |
| Jul 7, 1:19 PM MDT | Special Weather Statement | MSO | Lemhi | 26 min |
| Jul 7, 1:30 PM MDT | Severe Thunderstorm Warning | MSO | Lemhi | 30 min |
Nearby
Special Weather Statements in Montana, 2021Every special weather statement in 2021
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.