Alert archive / Montana / Special Weather Statements in 2021

Special Weather Statement, NWS Billings, MT

July 9, 2021Yellowstone County, Montana

NWS Billings, MT issued this special weather statement at Jul 9, 2021, 3:36 PM MDT for Yellowstone County, Montana. It was in force for 39 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: Jul 9, 2021, 3:36 PM MDT (21:36 UTC)
Expired: Jul 9, 2021, 4:15 PM MDT
In force: 39 min
Issued by: NWS Billings, MT

County Yellowstone County, MT

The radar

The Billings radar (KBLX), 16 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

Great_falls, MT (KTFX), launched 12:00Z, 9.6 hours before the alert went out and 241 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: 34 J/kg
Mixed-layer CIN: -410 J/kg
Mixed-layer LCL: 1971 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: -47 m²/s²
0-3 km storm-relative helicity: -52 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

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 Billings, MT wrote its last area forecast discussion before this special weather statement went out at Jul 9, 2:10 PM MDT, 1 hour 26 minutes earlier.

Area forecast discussion, Jul 9, 2:10 PM MDT, 1 hour 26 minutes before

Area Forecast Discussion
National Weather Service Billings MT
210 PM MDT Fri Jul 9 2021

.DISCUSSION...

This Afternoon through Saturday night...

An area of showers and thunderstorms is expected to develop early
this afternoon and shift southeast into the Billings area between
2 and 4 pm, then down into Sheridan in the 5 to 7 pm timeframe.
Main threat with these storms will be strong wind gusts, 30 to 50
mph from Billings to the northwest, and 40 to 60 mph to the
southeast of Billings down into Sheridan county. Another area of
weaker shower and thunderstorm activity will drop southward into
southeast Montana between 5 and 9 pm and linger into the late
night hours before shifting east and south overnight. By sunrise
should see clear skies and light winds across the area, which will
linger through Saturday. Temperatures tomorrow will be in the 85
to 95 degree range, a bit warmer than previous forecasts. Friday
night will be mostly clear with lows around 60 and generally light
southeast winds. Chambers

Sunday through Friday...

The big story for the extended forecast period is that is looking
more active, with periods of showers and thunderstorms. This may
not necessarily indicate significant wetting rain in any given
locations, although some locations may receive appreciable
amounts, but should help keep temps a bit cooler than seen in
recent days and weeks.

The upper ridge still dominates the pattern Sunday, bringing
temperatures back into the 90s, and will just break the century
mark for some locations. Sunday also looks very dry, at least to
start, with humidities possibly dropping into the single digits.
This will be the hottest day of the forecast period. Winds also
look fairly light to start, but will likely see afternoon mixing
to boost winds to 20 mph or better. All that said, as the ridge is
flattened in the west Sunday, PWATs jump fairly quickly. Have
added PoPs in the high terrain and foothills for Sunday evening.
Some storms may be dry to start, if manage to develop before
moisture has a chance to really get into the area.

A surface cold front is expected for Monday morning, bringing
slightly cooler temps. Shortwaves through the zonal to slightly
northwest flow Monday should bring potential for, at least,
isolated showers and thunder, even though best moisture appears to
stay north. A stronger system is expected for late Tuesday and
Wednesday, with an upper low slipping southeast across the
state. This appears to be the best shot for beneficial rain, if
it pans out as progged. There are some discrepencies amongst
models with regard to moisture availability, tracks, coverage,
etc, so NBM seems to be largely washing it out. Added higher, and
more widespread PoPs for this period.

Shortwave ridging builds in again for Thursday, allowing for a
bit of a warm up, but it is short-lived as another shortwave
crosses the region Thursday evening/night. Another wave, possibly
a little stronger, is expected Friday evening/night. We will need
to watch these systems closely, as ensembles are not handling
well, due to inconsistent timing and coverage.

Gilstad

&&

.AVIATION...

An area of showers and thunderstorms will move southeast across
the forecast area this afternoon and evening. These storms will
be capable of producing MVFR conditions in heavy rain along with
wind gusts up to 50 kts. Convection will move southeast of the
area by around 06z tonight with clear skies for the rest of the
night and through the day Saturday. Chambers

&&

.PRELIMINARY POINT TEMP/POPS...

    Sat     Sun     Mon     Tue     Wed     Thu     Fri
-----------------------------------------------------------
BIL 057/091 061/100 066/089 062/089 060/082 060/092 063/092
    10/U    00/U    20/U    23/T    34/T    11/U    21/U
LVM 049/093 053/098 056/090 054/087 053/083 052/091 054/090
    00/U    01/U    31/U    23/T    23/T    12/U    11/U
HDN 055/091 058/102 063/091 059/091 057/085 057/095 059/095
    20/U    00/G    00/U    23/T    33/T    11/U    21/U
MLS 059/088 061/099 067/091 060/088 060/083 061/092 064/095
    30/U    00/U    01/U    22/T    33/T    11/U    21/U
4BQ 058/086 058/096 066/092 061/087 060/081 061/089 064/092
    40/U    00/U    00/U    23/T    33/T    32/T    21/U
BHK 057/084 056/093 060/091 056/087 056/081 057/088 059/092
    31/T    00/U    01/U    22/T    32/T    21/U    21/U
SHR 051/087 053/096 060/089 056/087 054/080 055/089 056/090
    40/U    00/U    11/U    23/T    33/T    22/T    21/U

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.

&&

weather.gov/billings

In the hours before

Special weather statement, Jul 9, 2:39 PM MDT, 57 minutes before

Special Weather Statement
National Weather Service Billings MT
239 PM MDT Fri Jul 9 2021

MTZ034-042-141-092130-
Golden Valley MT-Northern Stillwater MT-Northern Sweet Grass MT-
239 PM MDT Fri Jul 9 2021

...SIGNIFICANT WEATHER ADVISORY...

At 238 PM MDT, Doppler radar was tracking a strong thunderstorm 19
miles southwest of Ryegate, or 28 miles northeast of Big Timber,
moving east at 30 mph.

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

Locations impacted include...
Halfbreed Lake Wildlife, Rapelje and Hailstone Wildlife Refuge.

LAT...LON 4610 10894 4583 10904 4600 10957 4616 10951
TIME...MOT...LOC 2038Z 288DEG 27KT 4606 10946

Tesar

Special weather statement, Jul 9, 3:18 PM MDT, 18 minutes before

Special Weather Statement
National Weather Service Billings MT
318 PM MDT Fri Jul 9 2021

MTZ034-235-092145-
Southwestern Yellowstone MT-Northern Stillwater MT-
318 PM MDT Fri Jul 9 2021

...SIGNIFICANT WEATHER ADVISORY...

At 318 PM MDT, Doppler radar was tracking a strong thunderstorm 16
miles northwest of Laurel, or 20 miles northeast of Columbus, moving
southeast at 35 mph.

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

Locations impacted include...
Laurel, Halfbreed Lake Wildlife, Park City and Molt.

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 4595 10870 4568 10870 4561 10897 4562 10899
      4587 10923 4601 10907
TIME...MOT...LOC 2118Z 300DEG 40KT 4587 10899

Tesar

Local storm report, Jul 9, 3:36 PM MDT, 0 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BILLINGS MT
336 PM MDT FRI JUL 09 2021

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

0240 PM     HAIL             2 NE GIBSON             46.04N 109.50W
07/09/2021  E0.25 INCH       SWEET GRASS        MT   CO-OP OBSERVER

0324 PM     HAIL             3 NW MOLT               45.90N 108.97W
07/09/2021  E0.25 INCH       STILLWATER         MT   TRAINED SPOTTER

0335 PM     HAIL             4 NNE LAUREL            45.72N 108.72W
07/09/2021  E0.50 INCH       YELLOWSTONE        MT   TRAINED SPOTTER

            PEA TO MARBLE SIZED HAIL.

&&

REIMER

Special weather statement, Jul 9, 3:36 PM MDT, 0 minutes before

Special Weather Statement
National Weather Service Billings MT
336 PM MDT Fri Jul 9 2021

MTZ235-092215-
Southwestern Yellowstone MT-
336 PM MDT Fri Jul 9 2021

...SIGNIFICANT WEATHER ADVISORY...

At 336 PM MDT, Doppler radar was tracking a strong thunderstorm 8
miles west of Billings West End, or 12 miles west of Billings, moving
southeast at 40 mph.

Dime size hail and wind gusts up to 50 mph are possible with this
storm.

Locations impacted include...
Billings, Laurel, Billings West End and Lockwood.

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 4573 10891 4576 10891 4589 10878 4575 10822
      4551 10851
TIME...MOT...LOC 2136Z 294DEG 34KT 4580 10879

Tesar

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 9, 2:39 PM MDT	Special Weather Statement	BYZ	Stillwater	51 min
Jul 9, 3:18 PM MDT	Special Weather Statement	BYZ	Stillwater	27 min
Jul 9, 4:12 PM MDT	Special Weather Statement	BYZ	Big Horn	48 min
Jul 9, 4:14 PM MDT	Special Weather Statement	BYZ	Carbon	46 min
Jul 9, 4:50 PM MDT	Special Weather Statement	BYZ	Big Horn	40 min
Jul 9, 5:04 PM MDT	Special Weather Statement	BYZ	Sheridan	26 min
Jul 9, 5:11 PM MDT	Special Weather Statement	BYZ	Sheridan	34 min
Jul 9, 5:51 PM MDT	Special Weather Statement	BYZ	Sheridan	39 min

Nearby

Special Weather Statements in Montana, 2021 Every 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.