Alert archive / Montana / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 1, NWS Missoula, MT

July 1, 2021Missoula County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Jul 1, 2021, 5:56 PM MDT for Missoula County, Montana. It was in force for 34 min. 5 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 1, 2021, 5:56 PM MDT (23:56 UTC)
Expired
Jul 1, 2021, 6:30 PM MDT
In force
34 min
Issued by
NWS Missoula, MT
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County Missoula County, MT

The radar

The Missoula radar (KMSX), 24 km from the middle of the area, began a volume at 23:55 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

TimeReportWhereRemark
Jul 1, 5:56 PM MDTTSTM WND GST 646 Wnw Missoula, MTCORRECTS PREVIOUS REPORT OF 64 MPH WIND GUST MEASURED AT KMSO ASOS WITH WIND OBSERVATION TIME OF 556 PM MDT.
Jul 1, 6:00 PM MDTTSTM WND DMG1 Sw Missoula, MTBROADCAST MEDIA REPORTS DOWNED POWER LINES AND ROOF DAMAGE NEAR BICKFORD STREET AND RONAN STREET. TIME OF REPORT ESTIMATED.
Jul 1, 6:00 PM MDTTSTM WND DMG2 Ssw Missoula, MTNWS EMPLOYEE REPORTS DOWNED POWERLINES ON KENT AVE. A 10 TO 12 INCH DIAMETER, 40 FOOT PINE TREE WAS SNAPPED HALFWAY UP. TIME OF DAMAGE ESTIMATED.
Jul 1, 6:05 PM MDTTSTM WND DMG5 Wnw Missoula, MTPHOTOS OF THREE DOWNED TREES ALONG MULLAN TRAIL ROAD IN MISSOULA.
Jul 1, 6:15 PM MDTTSTM WND DMG6 Wnw Missoula, MTA 8-12 INCH DIAMETER TREE BRANCH WAS DOWNED ALONG MULLAN ROAD IN MISSOULA. REPORT RETRIEVED VIA SOCIAL MEDIA. TIME OF DAMAGE ESTIMATED.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Spokane, WA (KOTX), launched 12:00Z, 11.9 hours before the alert went out and 201 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, Spokane, WA at 12:00Z on 2021-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Spokane, WA at 12:00Z on 2021-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -26 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3123 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
-26 m²/s²
0-3 km storm-relative helicity
109 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

958 
WUUS55 KMSO 012356
SVRMSO
MTC063-020030-
/O.NEW.KMSO.SV.W.0001.210701T2356Z-210702T0030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Missoula MT
556 PM MDT Thu Jul 1 2021

The National Weather Service in Missoula has issued a

* Severe Thunderstorm Warning for...
  South central Missoula County in west central Montana...

* Until 630 PM MDT.

* At 555 PM MDT, a severe thunderstorm was located over Lolo, or near
  Missoula, moving north at 10 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Missoula, Lolo and Wye. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4676 11392 4670 11417 4692 11436 4701 11399
TIME...MOT...LOC 2355Z 159DEG 10KT 4680 11409 

HAIL...<.75IN
WIND...60MPH
 
$$
2 follow-up statements
668 
WWUS55 KMSO 020008
SVSMSO

Severe Weather Statement
National Weather Service Missoula MT
608 PM MDT Thu Jul 1 2021

MTC063-020030-
/O.CON.KMSO.SV.W.0001.000000T0000Z-210702T0030Z/
Missoula MT-
608 PM MDT Thu Jul 1 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM MDT
FOR SOUTH CENTRAL MISSOULA COUNTY...

At 608 PM MDT, a severe thunderstorm was located over Lolo, or near
Missoula, moving northwest at 10 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Missoula, Lolo and Wye. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4680 11400 4677 11415 4692 11436 4701 11399
TIME...MOT...LOC 0008Z 156DEG 8KT 4682 11410 

HAIL...<.75IN
WIND...60MPH
 
$$
937 
WWUS55 KMSO 020029
SVSMSO

Severe Weather Statement
National Weather Service Missoula MT
629 PM MDT Thu Jul 1 2021

MTC063-020039-
/O.EXP.KMSO.SV.W.0001.000000T0000Z-210702T0030Z/
Missoula MT-
629 PM MDT Thu Jul 1 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL MISSOULA COUNTY
WILL EXPIRE AT 630 PM MDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.

LAT...LON 4680 11400 4677 11415 4692 11436 4701 11399
TIME...MOT...LOC 0029Z 159DEG 10KT 4687 11413 

$$

The office that day

Everything else NWS Missoula, MT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 1, 1:45 PM MDTRed Flag WarningMSOBeaverhead, Deer Lodge, Granite, Jefferson, Madison, Powell and 1 more30 hr
Jul 1, 3:42 PM MDTSpecial Weather StatementMSO48 min
Jul 1, 5:16 PM MDTSpecial Weather StatementMSOGranite44 min
Jul 1, 5:21 PM MDTSpecial Weather StatementMSOMissoula24 min
Jul 1, 5:23 PM MDTSpecial Weather StatementMSOPowell37 min
Jul 1, 5:42 PM MDTSpecial Weather StatementMSOMissoula48 min

Nearby

Severe Thunderstorm Warnings in Montana, 2021Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.