Alert archive / Montana / Special Weather Statements in 2021

Special Weather Statement, NWS Billings, MT

August 4, 2021Prairie County, Montana

NWS Billings, MT issued this special weather statement at Aug 4, 2021, 6:02 PM MDT for Prairie County, Montana. It was in force for 43 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 4, 2021, 6:02 PM MDT (00:02 UTC)
Expired
Aug 4, 2021, 6:45 PM MDT
In force
43 min
Issued by
NWS Billings, MT
Hail
0.50 in
Wind
40

County Prairie County, MT

The radar

The Glasgow radar (KGGW), 177 km from the middle of the area, began a volume at 00:04 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

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 0.0 hours before the alert went out and 178 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, Glasgow Intl Airport, MT at 00:00Z on 2021-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 133 joules per kilogram.LCLLFCEL10008507005003002001001 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, Glasgow Intl Airport, MT at 00:00Z on 2021-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -18 square meters per square second.1939Sfc1 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
133 J/kg
Mixed-layer CIN
-88 J/kg
Mixed-layer LCL
2787 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
-18 m²/s²
0-3 km storm-relative helicity
13 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

792 
WWUS85 KBYZ 050002
SPSBYZ

Special Weather Statement
National Weather Service Billings MT
602 PM MDT Wed Aug 4 2021
 
MTZ032-050045-
Custer MT-
602 PM MDT Wed Aug 4 2021

...A strong thunderstorm will impact portions of northwestern Custer
County through 645 PM MDT...

At 601 PM MDT, Doppler radar was tracking a strong thunderstorm 20
miles east of Hillside, or 30 miles north of Miles City, moving
southeast at 35 mph.

HAZARD...Heavy rainfall, winds in excess of 40 mph and half inch 
         hail.

SOURCE...Radar indicated.

IMPACT...Heavy rain could cause ponding of water on roads. Gusty 
         winds could knock down tree limbs and blow around unsecured 
         objects. Minor damage to outdoor objects is possible.

Locations impacted include...
Matthews Recreation Area and Strawberry Hill Recreation Area. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building. 

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

&&

LAT...LON 4686 10583 4683 10583 4683 10571 4679 10561
      4675 10562 4674 10557 4666 10558 4666 10550
      4660 10549 4660 10545 4657 10544 4637 10565
      4678 10613 4683 10612 4683 10608 4686 10608
TIME...MOT...LOC 0001Z 306DEG 29KT 4684 10599 

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

$$

Arthur

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 4, 6:46 PM MDTSpecial Weather StatementBYZWheatland44 min
Aug 5, 3:21 PM MDTSpecial Weather StatementBYZPark39 min
Aug 5, 4:02 PM MDTSpecial Weather StatementBYZPark43 min
Aug 5, 4:23 PM MDTSpecial Weather StatementBYZPark37 min
Aug 5, 4:57 PM MDTSpecial Weather StatementBYZPark48 min
Aug 5, 5:48 PM MDTSpecial Weather StatementBYZSweet Grass42 min

Nearby

Special Weather Statements in Montana, 2021Every special weather statement 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.