Severe Thunderstorm Warning 42, NWS Great Falls, MT

418 
WWUS55 KTFX 102300
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
500 PM MDT MON JUL 10 2017

MTC043-102309-
/O.CAN.KTFX.SV.W.0042.000000T0000Z-170710T2315Z/
Jefferson MT-
500 PM MDT MON JUL 10 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN JEFFERSON COUNTY
IS CANCELLED...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning has
been cancelled.  However small hail and gusty winds are still
possible with this thunderstorm.

LAT...LON 4607 11247 4621 11211 4594 11196 4585 11243
      4591 11241 4598 11245 4602 11244 4605 11248
TIME...MOT...LOC 2254Z 246DEG 25KT 4601 11226 

$$

Coulston

Area Forecast Discussion
National Weather Service Great Falls MT
255 PM MDT Mon Jul 10 2017

.SYNOPSIS...

Several upper-level disturbances will move through the region
through Tuesday. As a result, expect scattered showers and
thunderstorms to develop during this time, mainly during the
daylight hours. Some storms could be severe today, especially
over Southwest and Central Montana. Damaging wind gusts and
quarter-size or slightly bigger hail will be the main threats
from any severe storm. High temperatures will cool a few degrees
through Tuesday, before another significant heat wave develops by
late next week.

&&

.DISCUSSION...

Tonight through Tuesday Night...Multiple weather disturbances will
traverse our region from west to east tonight through Tuesday.
Thereafter, upper-level high pressure ridging will rebound over
the CWA Tuesday night. Accordingly, scattered showers and
thunderstorms today through tonight will become more intermittent
on Tuesday. Fair weather should then return Tuesday night. Severe
thunderstorms capable of damaging wind gusts and quarter-size or
slightly bigger hail are possible this afternoon and evening. In
addition, a few additional thunderstorms accompanied by quarter-
size or slightly larger hail cannot be ruled-out over/near the Hi-
Line overnight tonight. Near-average temperatures are expected
tonight through Tuesday night.
Jaszka

Wednesday through Sunday...After a brief reprieve from the warmest
temps of late, the western US ridge looks to rebuild in earnest
later this week. Models are in good agreement through about
Saturday, but then begin to diverge. The main point of contention is
how quickly an upper trough over the NRN Pacific will shift inland,
if at all. The EC/CMC have started to trend quicker, but as WPC
points out in their extended forecast discussion, the quicker
solutions have not worked out particularly well. So, for now, I kept
highs well into the 90s to near 100 late in the week and over the
weekend. If, however, the EC/CMC are correct, temps would likely not
be quite as hot by Sunday due to a flattening of the ridge. Of note,
ensemble guidance suggests the strength of the ridge forecast this
week has a return interval of about 5-10 years, although 850mb/700mb
temps do not show quite as high of a return interval. All this
points to unseasonably hot temperatures likely returning areawide
with near-record highs possible in a few locations. We encourage
everyone to plan for another extended period of well above normal
temperatures.

Each day, especially Wednesday through Saturday, isolated
thunderstorms may develop just about anywhere (as was seen this past
week) as weak shortwaves move beneath the ridge. Trying to pin down
any of these waves is next to impossible this far out, especially
since some may be driven by convection from previous days. For this
reason, I trended pops towards climo, with a slight favoring of the
SW MT mountains. No one day sticks out any more than another
regarding the threat of stronger storms, but all storms will likely
be capable of gusty winds with drier low levels/inverted V
environments.
MARTIN

&&

.FIRE WEATHER...

Critical fire weather conditions are expected across the
northeastern areas, where hot temperatures, low relative humidity,
and gusty winds will persist into this evening. This situation
will be complicated further by the potential for thunderstorms by
this late afternoon or early evening. For much of central
Montana, the primary fire weather threat will be strong
thunderstorms that produce frequent lightning and strong/gusty
erratic wind gusts. The best chance for stronger storms to occur
will be during this afternoon and evening hours.

Looking ahead, afternoon temperatures will cool a bit into the
80s for Tue/Wed, only for another significant heat wave to
develop on Thursday and continue into next weekend (afternoon
highs 90s/lower 100s). No significant/widespread rainfall is
expected after Tuesday at this time.
Cassell

&&

.AVIATION...
Updated 1720Z

Mainly VFR expected next 24-hours as multiple weather disturbances
cross the area from west to east. Scattered showers and
thunderstorms are expected, especially through 12Z/Tue. Severe
storms capable of hail up to quarter-size and surface gusts up to 60
knots are possible this afternoon and evening, especially over SW
and Central MT. Also, brief MVFR CIGS may accompany any shower or
storm.
Jaszka

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  56  83  53  90 /  20   0   0   0
CTB  53  78  50  86 /  40  20  10   0
HLN  57  86  56  91 /  30   0   0   0
BZN  53  84  51  88 /  20   0  10   0
WEY  48  76  41  79 /   0  10  20  10
DLN  53  82  51  85 /  10   0   0   0
HVR  60  84  54  91 /  20  20  10  10
LWT  55  81  52  85 /  60   0  10  10

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 11 PM MDT this evening Chouteau and
Fergus Counties...Hill and Blaine Counties.

&&

weather.gov/greatfalls

Special Weather Statement
National Weather Service Great Falls MT
325 PM MDT MON JUL 10 2017

MTZ015-055-102215-
Madison MT-Gallatin MT-
325 PM MDT MON JUL 10 2017

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN MADISON AND CENTRAL
GALLATIN COUNTIES UNTIL 415 PM MDT...

At 325 PM MDT, Doppler radar was tracking a strong thunderstorm 8
miles north of Ennis, or 14 miles northeast of Virginia City, moving
northeast at 30 mph.

Nickel size hail and wind gusts up to 50 mph will be possible with
this storm.

Locations impacted include...
Norris and Mcallister.

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 4535 11179 4552 11190 4572 11143 4546 11125
TIME...MOT...LOC 2125Z 244DEG 23KT 4547 11175

MLS

Special Weather Statement
National Weather Service Great Falls MT
327 PM MDT MON JUL 10 2017

MTZ008-015-102215-
Madison MT-Beaverhead MT-
327 PM MDT MON JUL 10 2017

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL MADISON AND SOUTHEASTERN
BEAVERHEAD COUNTIES UNTIL 415 PM MDT...

At 327 PM MDT, Doppler radar was tracking a strong thunderstorm 16
miles south of Alder, or 17 miles southwest of Virginia City, moving
northeast at 25 mph.

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

Locations impacted include...
Virginia City, Ennis, Jeffers and Cameron.

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 4494 11218 4513 11231 4542 11175 4510 11152
TIME...MOT...LOC 2127Z 246DEG 24KT 4508 11212

KJ

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
348 PM MDT MON JUL 10 2017

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

0317 PM     HAIL             4 N GLEN                45.53N 112.69W
07/10/2017  E0.75 INCH       MADISON            MT   CO-OP OBSERVER

            CO-OP OBSERVER REPORTED HAIL... ALONG WITH 0.76 INCHES
            OF RAIN

&&

KLG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
400 PM MDT MON JUL 10 2017

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

0252 PM     TSTM WND GST     7 SE HILGER             47.22N 109.22W
07/10/2017  M68 MPH          FERGUS             MT   MESONET

            JUDITH PEAK RAWS REPORTED A MAXIMUM WIND GUST OF 68 MPH

&&

KLG

Special Weather Statement
National Weather Service Great Falls MT
411 PM MDT MON JUL 10 2017

MTZ015-055-102300-
Madison MT-Gallatin MT-
411 PM MDT MON JUL 10 2017

...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL MADISON AND CENTRAL
GALLATIN COUNTIES UNTIL 500 PM MDT...

At 410 PM MDT, Doppler radar was tracking a strong thunderstorm 7
miles southeast of Virginia City, moving northeast at 40 mph.

Nickel size hail and wind gusts up to 50 mph will be possible with
this storm.

Locations impacted include...
Bozeman, Ennis, Jeffers, Big Sky and Cameron.

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 4508 11194 4524 11205 4566 11100 4552 11091
      4535 11093 4535 11104 4529 11104
TIME...MOT...LOC 2210Z 244DEG 55KT 4523 11181

MLS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
431 PM MDT MON JUL 10 2017

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

0306 PM     HAIL             1 W GLEN                45.48N 112.71W
07/10/2017  M1.00 INCH       BEAVERHEAD         MT   PUBLIC

            QUARTER SIZED HAIL REPORTED JUST WEST OF GLEN ON
            INTERSTATE 15 AT 306 PM.

&&

COULSTON