Special Weather Statement, NWS Great Falls, MT

Area Forecast Discussion
National Weather Service Great Falls MT
155 PM MDT Mon Jul 5 2021

.SYNOPSIS...
A few isolated thunderstorms will be possible through tonight over
the area, while drier and warmer temperatures move into the area
for Tuesday. On Wednesday, there will be another chance for
thunderstorms for most areas. By late in the week, widespread
temperatures in the 90s along with mostly dry conditions are
expected to redevelop.

&&

.DISCUSSION...
Tonight through Wednesday...Expect a few thunderstorms over
Southwest MT this evening, why a stronger upper level disturbance
will moves across the Hi-line area overnight. There is a marginal
risk for severe storms tonight for areas north of Great Falls,
with the potential for any severe storms likely occurring during
the overnight hours. On Tuesday, it turns drier and warmer ahead
of the next upper level disturbance. That disturbance will move
through the region on Wednesday, resulting in isolated storms for
most areas. Again, an isolated severe storm is possible on
Wednesday.

Thursday through Monday...Drier air returns to the region by late
in the week and into the weekend, as shortwave ridging develops
over the region. The chances for storms will start to increase by
next Monday, as the next upper level trof approaches the area.
Brusda

&&

.AVIATION...
1155 AM MDT Mon Jul 5 2021 (05/18Z TAF period)

Rain showers are moving northeast from the Bozeman area towards
Lewistown early this afternoon, while low clouds continue over
portions of North Central MT. Showers decrease over Central MT by
late afternoon, however showers/thunderstorms redevelop tonight in
the Cut Bank/Havre area. MVFR conditions will continue into this
evening over portions of North Central MT and in the showers.
Mountains/passes will be obscured at times through 10z Tuesday.
Brusda

Refer to weather.gov/zlc for more detailed regional
aviation weather and hazard information.

&&

.FIRE WEATHER...
A few storms will affect the region tonight, but drier and warmer
conditions develop on Tuesday. For Wednesday, expect a chance for
storms in most areas. By Thursday, windy west winds are forecast
to develop. Thus there is the potential for fire highlights on
Wednesday and Thursday, with Thursday looking like the more likely
day at this time. Looking ahead, it remains very warm/hot over the
weekend, along with mostly dry conditions. Brusda

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  54  90  54  92 /  10   0   0  20
CTB  52  84  53  85 /  40  10   0  20
HLN  58  96  60  96 /  10   0   0  20
BZN  52  94  53  96 /  10   0   0  20
WYS  40  84  42  86 /  20   0   0  10
DLN  52  91  53  93 /  10   0   0  20
HVR  59  86  56  93 /  50  40  10  10
LWT  56  86  55  92 /  20  30   0  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 9 PM MDT this evening Eastern Beaverhead
National Forest.

&&

http://www.weather.gov/greatfalls

Special Weather Statement
National Weather Service Great Falls MT
259 PM MDT Mon Jul 5 2021

MTZ052-052130-
Jefferson-
259 PM MDT Mon Jul 5 2021

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL JEFFERSON COUNTY...

At 259 PM MDT, a strong thunderstorm was located near Basin, or 12
miles west of Boulder, moving east at 10 mph.

Winds in excess of 30 mph, brief heavy rain, and pea size hail are
possible with this storm.

Locations impacted include...
Boulder, Basin and Wickes.

This includes Interstate 15 between mile markers 142 and 171.

If outdoors, consider seeking shelter inside a building.

LAT...LON 4614 11244 4631 11250 4646 11209 4610 11201
TIME...MOT...LOC 2059Z 256DEG 8KT 4625 11237

SC

Special Weather Statement
National Weather Service Great Falls MT
331 PM MDT Mon Jul 5 2021

MTZ052-052200-
Jefferson-
331 PM MDT Mon Jul 5 2021

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT JEFFERSON COUNTY...

At 330 PM MDT, radar indicated strong thunderstorms were located
along a line extending from 11 miles north of Basin to 9 miles south
of Boulder to near Silver Bow. Movement was southeast at 15 mph.

Winds in excess of 30 mph and brief heavy rain are possible with
these storms.

Locations impacted include...
Boulder, Whitehall, Basin, Wickes, Alhambra, Corbin, Clancy,
Jefferson City, Elkhorn State Park and Cardwell.

This includes the following highways...
 Interstate 15 near mile marker 134, and between mile markers 153 and
184.
 Interstate 90 between mile markers 235 and 255.

If outdoors, consider seeking shelter inside a building.

LAT...LON 4612 11224 4638 11238 4645 11219 4646 11217
      4649 11221 4651 11218 4650 11190 4592 11175
      4585 11209 4579 11229 4585 11243 4591 11241
      4604 11246
TIME...MOT...LOC 2130Z 296DEG 12KT 4643 11235 4610 11218 4593 11263

SC

Special Weather Statement
National Weather Service Great Falls MT
427 PM MDT Mon Jul 5 2021

MTZ015-052-052300-
Madison-Jefferson-
427 PM MDT Mon Jul 5 2021

...A STRONG THUNDERSTORM WILL AFFECT NORTH CENTRAL MADISON
AND SOUTHERN JEFFERSON COUNTIES...

At 426 PM MDT, a strong thunderstorm was located near Butte, moving
southeast at 15 mph.

Winds in excess of 30 mph, brief heavy rain, and pea size hail are
possible with this storm.

Locations impacted include...
Whitehall, Silver Star, Pony, Cardwell, Waterloo and Lewis And Clark
Caverns State Park.

This includes the following highways...
 Interstate 90 between mile markers 235 and 261.
 Highway 287 between mile markers 80 and 85.

If outdoors, consider seeking shelter inside a building.

LAT...LON 4576 11250 4574 11247 4575 11219 4585 11243
      4591 11241 4603 11244 4584 11170 4579 11174
      4579 11177 4577 11176 4545 11200 4573 11253
TIME...MOT...LOC 2226Z 302DEG 11KT 4589 11249

SC

Special Weather Statement
National Weather Service Great Falls MT
506 PM MDT Mon Jul 5 2021

MTZ015-052330-
Madison-
506 PM MDT Mon Jul 5 2021

...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN MADISON COUNTY...

At 505 PM MDT, a strong thunderstorm was located 11 miles northwest
of Silver Star, or 15 miles south of Butte, moving southeast at 15
mph.

Winds in excess of 30 mph, brief heavy rain, and pea size hail are
possible with this storm.

Locations impacted include...
Silver Star and Waterloo.

If outdoors, consider seeking shelter inside a building.

LAT...LON 4570 11253 4576 11250 4574 11247 4575 11243
      4575 11222 4570 11215 4552 11243 4568 11258
TIME...MOT...LOC 2305Z 317DEG 12KT 4576 11249

SC