Alert archive / Montana / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 47, NWS Missoula, MT

July 20, 2012Lincoln County, Mineral County, Sanders County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Jul 20, 2012, 4:31 PM MDT for Lincoln County, Mineral County, Sanders County, Montana. It was in force for 59 min. 2 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 20, 2012, 4:31 PM MDT (22:31 UTC)
Expired
Jul 20, 2012, 5:30 PM MDT
In force
59 min
Issued by
NWS Missoula, MT
Area
Storm-based polygon

Counties Lincoln County, MT, Mineral County, MT, Sanders County, MT

The radar

The Missoula radar (KMSX), 118 km from the middle of the area, began a volume at 22:33 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 20, 5:00 PM MDTTSTM WND DMGThompson Falls, MTSEVERAL TREES DOWN ALONG MAIN STREET
Jul 20, 5:00 PM MDTHAIL 1Thompson Falls, MT

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jul 20, 12:38 PM MDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Spokane, WA (KOTX), launched 12:00Z, 10.5 hours before the alert went out and 78 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 2012-07-20Temperature 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 2012-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 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
2619 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
66 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

380 
WUUS55 KMSO 202231
SVRMSO
MTC053-061-089-202330-
/O.NEW.KMSO.SV.W.0047.120720T2231Z-120720T2330Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
431 PM MDT FRI JUL 20 2012

THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL SANDERS COUNTY IN NORTHWEST MONTANA...
  SOUTHERN LINCOLN COUNTY IN NORTHWEST MONTANA...
  NORTHWESTERN MINERAL COUNTY IN WEST CENTRAL MONTANA...

* UNTIL 530 PM MDT.

* AT 424 PM MDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM
  CAPABLE OF PRODUCING GOLF BALL SIZE HAIL...AND DESTRUCTIVE WINDS IN
  EXCESS OF 70 MPH.  THIS STORM WAS LOCATED 16 MILES SOUTHWEST OF
  HAUGAN...OR ABOUT 22 MILES WEST OF SAINT REGIS...AND WAS MOVING
  NORTHEAST AT 35 MPH.

* LOCATIONS IMPACTED INCLUDE...BELKNAP...BEND...DE BORGIA...EAST
  PORTAL...EDDY...HAUGAN...PARADISE...PLAINS...SALTESE...SNIDER...
  SAINT REGIS...TAFT...THOMPSON FALLS AND WEEKSVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DAMAGING WINDS ARE LIKELY WITH THIS SEVERE THUNDERSTORM. LARGE HAIL
IS POSSIBLE...ALONG WITH FREQUENT LIGHTNING AND HEAVY RAIN. FOR YOUR
PROTECTION...GO INDOORS AND STAY AWAY FROM WINDOWS. IF YOU ARE CAUGHT
OUTSIDE...MOVE TO A WELL PROTECTED AREA.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM MDT FRIDAY
EVENING FOR NORTH CENTRAL IDAHO AND NORTHWESTERN MONTANA.

&&

LAT...LON 4746 11573 4746 11565 4749 11570 4804 11513
      4745 11464 4713 11522 4719 11530 4726 11534
      4725 11541 4729 11552 4737 11561 4737 11564
      4743 11576
TIME...MOT...LOC 2231Z 216DEG 29KT 4723 11550

$$
KITSMILLER
1 follow-up statement
893 
WWUS55 KMSO 202327
SVSMSO

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MISSOULA MT
527 PM MDT FRI JUL 20 2012

MTC053-061-089-202335-
/O.EXP.KMSO.SV.W.0047.000000T0000Z-120720T2330Z/
MINERAL MT-LINCOLN MT-SANDERS MT-
527 PM MDT FRI JUL 20 2012

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL SANDERS...SOUTHERN
LINCOLN AND NORTHWESTERN MINERAL COUNTIES EXPIRES AT 530 PM MDT...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM MDT FRIDAY
EVENING FOR NORTH CENTRAL IDAHO AND NORTHWESTERN MONTANA.

LAT...LON 4746 11573 4746 11565 4749 11570 4804 11513
      4745 11464 4713 11522 4719 11530 4726 11534
      4725 11541 4729 11552 4737 11561 4737 11564
      4743 11576
TIME...MOT...LOC 2325Z 216DEG 29KT 4758 11512

$$
KITSMILLER

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 2:41 PM MDTSpecial Weather StatementMSODeer Lodge49 min
Jul 20, 3:05 PM MDTSpecial Weather StatementMSOMissoula55 min
Jul 20, 3:09 PM MDTSevere Thunderstorm WarningMSOMineral, Missoula, Ravalli, Sanders51 min
Jul 20, 3:30 PM MDTSpecial Weather StatementMSOLake60 min
Jul 20, 3:46 PM MDTSpecial Weather StatementMSOPowell44 min
Jul 20, 3:52 PM MDTSpecial Weather StatementMSOSanders53 min
Jul 20, 4:21 PM MDTSevere Thunderstorm WarningMSOLincoln, Sanders39 min
Jul 20, 4:32 PM MDTSpecial Weather StatementMSOFlathead, Lake58 min
Jul 20, 4:53 PM MDTSevere Thunderstorm WarningMSOFlathead, Lincoln, Sanders67 min

Nearby

Severe Thunderstorm Warnings in Montana, 2012Every severe thunderstorm warning in 2012

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.