Alert archive / Montana / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 13, NWS Missoula, MT

July 15, 2017Missoula County, Ravalli County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Jul 15, 2017, 4:59 PM MDT for Missoula County, Ravalli County, Montana. It was in force for 46 min. 3 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 15, 2017, 4:59 PM MDT (22:59 UTC)
Expired
Jul 15, 2017, 5:45 PM MDT
In force
46 min
Issued by
NWS Missoula, MT
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Missoula County, MT, Ravalli County, MT

The radar

The Missoula radar (KMSX), 37 km from the middle of the area, began a volume at 23:03 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 was reported inside it

TimeReportWhereRemark
Jul 15, 4:59 PM MDTTSTM WND DMG3 E Florence, MTA LARGE TREE FELL ONTO A HOUSE AND BROKE THE SKYLIGHT.
Jul 15, 4:59 PM MDTNON-TSTM WND GST 603 E Florence, MTWIND GUSTS 50 TO 60 MPH AND HEAVY RAIN.
Jul 15, 5:42 PM MDTTSTM WND GST 602 Nw Clinton, MTPOWER OUTAGE.

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, 11.0 hours before the alert went out and 221 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 2017-07-15Temperature 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 2017-07-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 44 square meters per square second.19395878Sfc1 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
2875 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
44 m²/s²
0-3 km storm-relative helicity
121 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

435 
WUUS55 KMSO 152259
SVRMSO
MTC063-081-152345-
/O.NEW.KMSO.SV.W.0013.170715T2259Z-170715T2345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Missoula MT
459 PM MDT SAT JUL 15 2017

The National Weather Service in Missoula has issued a

* Severe Thunderstorm Warning for...
  Southeastern Missoula County in west central Montana...
  North central Ravalli County in west central Montana...

* Until 545 PM MDT

* At 458 PM MDT, a severe thunderstorm was located over Florence, or
  16 miles south of Missoula, moving northeast at 30 mph.

  HAZARD...60 mph wind gusts, heavy rain and penny size hail. 

  SOURCE...Radar indicated. 

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

* Locations impacted include...
  Missoula, Lolo, Bonner-West Riverside, Florence, East Missoula,
  Clinton and Turah.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Wind damage with this storm will occur before any rain or lightning.
Do not wait for the sound of thunder before taking cover. SEEK
SHELTER IMMEDIATELY inside a sturdy structure and stay away from
windows.

&&

LAT...LON 4680 11352 4666 11379 4666 11382 4664 11382
      4652 11404 4668 11433 4700 11398
TIME...MOT...LOC 2258Z 224DEG 26KT 4664 11410 

HAIL...0.75IN
WIND...60MPH
 
$$
1 follow-up statement
132 
WWUS55 KMSO 152339
SVSMSO

Severe Weather Statement
National Weather Service Missoula MT
539 PM MDT SAT JUL 15 2017

MTC063-081-152349-
/O.EXP.KMSO.SV.W.0013.000000T0000Z-170715T2345Z/
Missoula MT-Ravalli MT-
539 PM MDT SAT JUL 15 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN MISSOULA AND
NORTH CENTRAL RAVALLI COUNTIES WILL EXPIRE AT 545 PM MDT...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.

LAT...LON 4680 11352 4666 11379 4666 11382 4664 11382
      4652 11404 4668 11433 4700 11398
TIME...MOT...LOC 2339Z 224DEG 26KT 4685 11381 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 14, 6:16 PM MDTSpecial Weather StatementMSOMissoula29 min
Jul 14, 7:57 PM MDTSpecial Weather StatementMSOMissoula33 min
Jul 15, 2:00 PM MDTRed Flag WarningMSOFlathead, Glacier, Granite, Lake, Lewis and Clark, Lincoln and 5 more31 hr
Jul 15, 2:29 PM MDTSpecial Weather StatementMSODeer Lodge46 min
Jul 15, 2:58 PM MDTSpecial Weather StatementMSORavalli62 min
Jul 15, 3:35 PM MDTSpecial Weather StatementMSORavalli40 min
Jul 15, 4:03 PM MDTSpecial Weather StatementMSORavalli27 min
Jul 15, 4:16 PM MDTSpecial Weather StatementMSORavalli59 min
Jul 15, 4:27 PM MDTSevere Thunderstorm WarningMSOMissoula, Ravalli33 min
Jul 15, 5:13 PM MDTSpecial Weather StatementMSODeer Lodge47 min
Jul 15, 5:41 PM MDTAreal Flood AdvisoryMSODeer Lodge64 min
Jul 15, 5:49 PM MDTSpecial Weather StatementMSOMissoula41 min
Jul 15, 5:53 PM MDTSpecial Weather StatementMSOPowell52 min

Nearby

Severe Thunderstorm Warnings in Montana, 2017Every severe thunderstorm warning in 2017

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.