Alert archive / Montana / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 12, NWS Missoula, MT

July 8, 2013Lake County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Jul 8, 2013, 3:33 PM MDT for Lake County, Montana. It was in force for 27 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 8, 2013, 3:33 PM MDT (21:33 UTC)
Expired: Jul 8, 2013, 4:00 PM MDT
In force: 27 min
Issued by: NWS Missoula, MT
Area: Storm-based polygon

County Lake County, MT

The radar

The Missoula radar (KMSX), 68 km from the middle of the area, began a volume at 21:35 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.

The nearest sounding before it

Spokane, WA (KOTX), launched 12:00Z, 9.6 hours before the alert went out and 173 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 41 J/kg
Mixed-layer CIN: -248 J/kg
Mixed-layer LCL: 1886 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 71 m²/s²
0-3 km storm-relative helicity: 91 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning 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 severe thunderstorm warning went out at Jul 8, 2:35 PM MDT, 58 minutes earlier.

Area forecast discussion, Jul 8, 2:35 PM MDT, 58 minutes before

Area Forecast Discussion
National Weather Service Missoula MT
235 PM MDT Mon Jul 8 2013

.DISCUSSION...
Tonight...Scattered showers and thunderstorms will continue this
afternoon and evening across western Montana and Lemhi county in
response to a passing weather disturbance. Some of the
thunderstorms will be strong enough to produce small hail, gusty
winds and brief heavy rain. The thunderstorm threat will diminish
this evening once the sun sets below the horizon and drier air
moves in from the west. Drier air has already started to move into
Clearwater and Idaho counties of north-central Idaho where we have
seen convective activity decrease this afternoon. This disturbance
will be moving into southern Alberta later this evening resulting
in clearing skies and calm conditions.

Tuesday through Wednesday...A ridge of high pressure will develop
and strengthen during this period. Warmer, dry conditions are
expected. There is a potential for high-based thunderstorm late
Wednesday afternoon across west-central Montana and Lemhi county
(south of Missoula) if enough monsoonal moisture creeps northward
from the Great Basin region.

The models are indicating that the ridge of high pressure will
move off to the east as a trough digs along the coast. This
movement of the ridge axis will cause slightly cooler
temperatures, but an increase in afternoon/evening winds. The
trough is expected to flatten and move inland causing westerly
flow over the Northern Rockies. This flow pattern will keep
temperatures near normal readings with gusty afternoon and evening
winds. The timing of weak disturbances through the flow is
uncertain at this time, but shower activity is anticipated to be
fairly minimal.

&&

.AVIATION... Scattered showers and thunderstorms continue across
western Montana and Lemhi county in response to a passing weather
disturbance. Some of the thunderstorms will be strong enough to
produce hail, gusty winds and brief heavy rain. KGPI and KBTM have
the greatest chance of being impacted by storms. Mountain tops
will be occasionally obscured in clouds and precipitation through
the evening hours. The thunderstorm threat will diminish this
evening once the sun sets below the horizon and drier air moves in
from the west. Drier air has already started to move into
Clearwater and Idaho counties of north-central Idaho where we have
seen convective activity decrease. This drying trend will extend
into western Montana as this disturbance moves into southern
Alberta later this evening. Favorable conditions for aviation
operations can be expected as skies clear and calm conditions
prevail into Tuesday.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

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In the hours before

Local storm report, Jul 8, 2:22 PM MDT, 1 hour 11 minutes before

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Local storm report, Jul 8, 2:27 PM MDT, 1 hour 6 minutes before

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      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
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Special weather statement, Jul 8, 2:44 PM MDT, 49 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MISSOULA MT
244 PM MDT MON JUL 8 2013

MTZ002-003-082130-
FLATHEAD/MISSION VALLEYS-WEST GLACIER REGION-
244 PM MDT MON JUL 8 2013

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN FLATHEAD COUNTY UNTIL
330 PM MDT...

AT 235 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 9 MILES NORTHEAST OF WHITEFISH...OR 20 MILES
NORTH OF EVERGREEN...MOVING NORTHEAST AT 20 MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 50 MPH ARE
EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN AND FREQUENT
DANGEROUS LIGHTNING.

LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...WEST GLACIER...
GOING-TO-THE-SUN ROAD IN GLACIER PARK...APGAR...LAKE MCDONALD AND
LOGAN PASS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

&&

LAT...LON 4885 11379 4881 11374 4877 11375 4874 11370
      4862 11374 4859 11360 4859 11355 4856 11350
      4841 11422 4857 11432 4883 11398 4886 11385
TIME...MOT...LOC 2044Z 247DEG 16KT 4853 11414

DICKERSON

Local storm report, Jul 8, 2:48 PM MDT, 45 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
248 PM MDT MON JUL 8 2013

...TIME...  ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
...DATE...  ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0244 PM     HAIL             PARADISE                47.39N 114.81W
07/08/2013  E0.50 INCH       SANDERS            MT   PUBLIC

            DIME SIZED HAIL.

&&

IRIS SYSTEM

Special weather statement, Jul 8, 3:17 PM MDT, 16 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MISSOULA MT
317 PM MDT MON JUL 8 2013

MTZ007-082200-
BUTTE/BLACKFOOT REGION-
317 PM MDT MON JUL 8 2013

...SIGNIFICANT WEATHER ADVISORY FOR EASTERN GRANITE...SOUTHEASTERN
POWELL...NORTHERN SILVER BOW AND NORTHERN DEER LODGE COUNTIES UNTIL
400 PM MDT...

AT 312 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM NEAR WEST VALLEY...OR 5 MILES WEST OF ANACONDA...
MOVING EAST AT 45 MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 40 MPH ARE
EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN AND FREQUENT
DANGEROUS LIGHTNING.

LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...WARM SPRINGS...
GALEN...LOST CREEK...OPPORTUNITY AND RACETRACK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF THREATENING WEATHER APPROACHES YOUR AREA...GO INDOORS AND STAY
AWAY FROM WINDOWS. IF YOU ARE CAUGHT OUTSIDE...MOVE TO A WELL
PROTECTED AREA.

IN ADDITION...THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR
LOCAL RADIO AND TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR
ADDITIONAL INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL
WEATHER SERVICE.

&&

LAT...LON 4642 11231 4638 11235 4638 11240 4633 11245
      4632 11253 4630 11256 4619 11257 4619 11251
      4611 11250 4601 11323 4619 11329 4654 11232
      4645 11229
TIME...MOT...LOC 2117Z 256DEG 41KT 4616 11296

DICKERSON

Special weather statement, Jul 8, 3:20 PM MDT, 13 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MISSOULA MT
320 PM MDT MON JUL 8 2013

MTZ002>004-043-082200-
FLATHEAD/MISSION VALLEYS-LOWER CLARK FORK REGION-POTOMAC/SEELEY LAKE
REGION-WEST GLACIER REGION-
320 PM MDT MON JUL 8 2013

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN SANDERS...SOUTHERN
LAKE AND NORTHERN MISSOULA COUNTIES UNTIL 400 PM MDT...

AT 312 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 8 MILES NORTH OF DIXON...OR 19 MILES SOUTH OF
POLSON...MOVING EAST AT 35 MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 40 MPH ARE
EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN AND FREQUENT
DANGEROUS LIGHTNING.

LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...SAINT IGNATIUS...
RONAN...CHARLO...ALLENTOWN...FORT CONNAH...KICKING HORSE AND CONDON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF THREATENING WEATHER APPROACHES YOUR AREA...GO INDOORS AND STAY
AWAY FROM WINDOWS. IF YOU ARE CAUGHT OUTSIDE...MOVE TO A WELL
PROTECTED AREA.

IN ADDITION...THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR
LOCAL RADIO AND TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR
ADDITIONAL INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL
WEATHER SERVICE.

&&

LAT...LON 4764 11369 4733 11359 4723 11444 4752 11450
TIME...MOT...LOC 2120Z 261DEG 30KT 4744 11422

DICKERSON

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 8, 7:14 AM MDT	Special Weather Statement	MSO	Powell	46 min
Jul 8, 11:31 AM MDT	Special Weather Statement	MSO	Granite	29 min
Jul 8, 11:37 AM MDT	Severe Thunderstorm Warning	MSO	Ravalli	23 min
Jul 8, 1:41 PM MDT	Special Weather Statement	MSO	Flathead	49 min
Jul 8, 2:08 PM MDT	Special Weather Statement	MSO	Ravalli	37 min
Jul 8, 2:27 PM MDT	Severe Thunderstorm Warning	MSO	Mineral, Sanders	48 min
Jul 8, 2:37 PM MDT	Areal Flood Advisory	MSO	Flathead	113 min
Jul 8, 2:44 PM MDT	Special Weather Statement	MSO	Flathead	46 min
Jul 8, 3:17 PM MDT	Special Weather Statement	MSO	Deer Lodge	43 min
Jul 8, 3:20 PM MDT	Special Weather Statement	MSO	Lake	40 min
Jul 8, 4:12 PM MDT	Severe Thunderstorm Warning	MSO	Missoula	33 min
Jul 8, 8:36 AM MDT	Special Weather Statement	MSO	Idaho	39 min

Nearby

Severe Thunderstorm Warnings in Montana, 2013 Every severe thunderstorm warning in 2013

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.