Alert archive / Montana / Special Weather Statements in 2019

Special Weather Statement, NWS Missoula, MT

August 2, 2019Missoula County, Montana

NWS Missoula, MT issued this special weather statement at Aug 2, 2019, 4:22 PM MDT for Missoula County, Montana. It was in force for 23 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: Aug 2, 2019, 4:22 PM MDT (22:22 UTC)
Expired: Aug 2, 2019, 4:45 PM MDT
In force: 23 min
Issued by: NWS Missoula, MT

County Missoula County, MT

The radar

The Missoula radar (KMSX), 31 km from the middle of the area, began a volume at 22:24 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, 10.4 hours before the alert went out and 223 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2829 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 9 m²/s²
0-3 km storm-relative helicity: 108 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

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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 Aug 2, 2:36 PM MDT, 1 hour 46 minutes earlier.

Area forecast discussion, Aug 2, 2:36 PM MDT, 1 hour 46 minutes before

Area Forecast Discussion
National Weather Service Missoula MT
236 PM MDT Fri Aug 2 2019

...GUSTY WINDS ACROSS NORTHERN ROCKIES TODAY...

.DISCUSSION...

Thunderstorms and gusty winds will be present across portions of the
Northern Rockies through late this evening. Much of the
thunderstorm activity will be present across Lemhi County and
southwest Montana. By 6pm, storms will migrate north of Interstate
90, impacting areas as far west as Superior and as far north as
Flathead Lake. Some of these storms will be capable of producing
erratic wind gusts to 50 mph and very little precipitation. Most
thunderstorm activity will dissipate after midnight.

Daytime temperatures across the Northern Rockies will cool
several degrees on Saturday, before warming back to well-above
normal reading Sunday through at least Wednesday. Heat exhaustion
and the cumulative effects of day-after-day hot temperatures will
create a health hazard. Remember to not leave children or pets in
the car.

Thunderstorms will creep back into the weather picture beginning
Monday afternoon/evening, and redevelop each day through
Wednesday. These storms be mostly confined to near the
Continental Divide from Lemhi County Idaho northward to MacDonald
Pass in Montana (including Salmon, Butte, Georgetown Lake).

By Thursday, models suggest that a closed low pressure circulation
over Pacific Northwest coast will move eastward over the Northern
Rockies. Increased chances of showers and thunderstorms will exist
Thursday through next weekend for much of the Northern Rockies.
Temperatures are expected to cool down to slightly below the
seasonal average during this time.

&&

.AVIATION...

Thunderstorms will be present across portions of the Northern
Rockies through 03/0600Z, including terminals KMSO, KBTM, and
KSMN. Most wind gusts at the aforementioned terminals will be 30
knots or less, however thunderstorm winds may exceed 40 knots
briefly. Thunderstorms may briefly lower ceilings and visibility. Likely
timing for thunderstorms...KMSO: 02/2300Z - 03/0400Z...KBTM:
02/2200Z - 03/0400Z...KSMN: 02/2100Z - 03/0300Z. Terrain
obscurations will accompany thunderstorm activity and be most
prominent along the Continental Divide. Thunderstorms, wind gusts,
and terrain obscurations will dissipate after 03/0600Z.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...     Red Flag Warning until 10 PM MDT this evening Flathead/Glacier
     Park...Kootenai...Salish and Kootenai Reservation.

     Red Flag Warning until 11 PM MDT this evening Bitterroot...East
     Lolo.

     Red Flag Warning until 9 PM MDT this evening Deerlodge/West
     Beaverhead...East Beaverhead.

ID...&&

In the hours before

Special weather statement, Aug 2, 2:53 PM MDT, 1 hour 29 minutes before

Special Weather Statement
National Weather Service Missoula MT
153 PM PDT Fri Aug 2 2019

IDZ006-022145-
Southern Clearwater Mountains ID-
153 PM PDT Fri Aug 2 2019

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN LEMHI...SOUTHEASTERN
IDAHO AND SOUTHWESTERN RAVALLI COUNTIES UNTIL 245 PM PDT...

At 152 PM PDT, Doppler radar was tracking a strong thunderstorm 48
miles west of North Fork, or 57 miles northwest of Salmon, moving
northeast at 40 mph.

Half inch hail and wind gusts of 50 to 55 mph will be possible with
this storm.

This storm will remain over mainly rural areas of northwestern Lemhi,
southeastern Idaho and southwestern Ravalli Counties.

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 4634 11443 4628 11443 4626 11447 4617 11444
      4614 11452 4610 11446 4603 11451 4598 11441
      4594 11443 4588 11439 4585 11450 4578 11456
      4571 11450 4564 11456 4558 11456 4549 11474
      4551 11478 4546 11479 4537 11497 4549 11533
TIME...MOT...LOC 2052Z 219DEG 38KT 4550 11499

Local storm report, Aug 2, 4:07 PM MDT, 15 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
407 PM MDT FRI AUG 2 2019

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

0400 PM     HAIL             4 E FLORENCE            46.63N 114.00W
08/02/2019  M0.50 INCH       RAVALLI            MT   PUBLIC

            REPORT RETRIEVED FROM SOCIAL MEDIA.

&&

AL

Special weather statement, Aug 2, 4:22 PM MDT, 0 minutes before

Special Weather Statement
National Weather Service Missoula MT
422 PM MDT Fri Aug 2 2019

MTZ006-043-022245-
Bitterroot/Sapphire Mountains MT-Potomac/Seeley Lake Region MT-
422 PM MDT Fri Aug 2 2019

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN MISSOULA COUNTY
UNTIL 445 PM MDT...

At 422 PM MDT, Doppler radar was tracking a strong thunderstorm 7
miles southeast of Bonner-West Riverside, or 10 miles southeast of
Missoula, moving northeast at 30 mph.

Dime size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Twin Creeks and Clinton.

LAT...LON 4672 11379 4675 11388 4695 11374 4693 11355
TIME...MOT...LOC 2222Z 214DEG 24KT 4679 11381

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 2, 4:23 PM MDT	Special Weather Statement	MSO	Powell	52 min
Aug 2, 5:31 PM MDT	Special Weather Statement	MSO		59 min
Aug 2, 5:45 PM MDT	Special Weather Statement	MSO	Missoula	45 min
Aug 2, 5:49 PM MDT	Special Weather Statement	MSO	Powell	41 min
Aug 2, 2:53 PM MDT	Special Weather Statement	MSO	Idaho	52 min
Aug 2, 5:36 PM MDT	Special Weather Statement	MSO	Idaho	54 min

Nearby

Special Weather Statements in Montana, 2019 Every special weather statement in 2019

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.