Severe Thunderstorm Warning 41, NWS Great Falls, MT

896 
WWUS55 KTFX 102141
SVSTFX

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

MTC001-057-102151-
/O.EXP.KTFX.SV.W.0041.000000T0000Z-170710T2145Z/
Madison MT-Beaverhead MT-
341 PM MDT MON JUL 10 2017

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL MADISON AND NORTH
CENTRAL BEAVERHEAD COUNTIES WILL EXPIRE AT 345 PM MDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore the warning will be allowed to expire.  However small hail
and gusty winds are still possible with this thunderstorm.

LAT...LON 4567 11270 4563 11270 4566 11260 4551 11230
      4534 11268 4545 11288
TIME...MOT...LOC 2141Z 217DEG 14KT 4553 11265 

$$

KJ

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

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

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

0142 PM     TSTM WND GST     2 SSE GEYSER            47.25N 110.48W
07/10/2017  M56 MPH          JUDITH BASIN       MT   DEPT OF HIGHWAYS

            MDT GEYSER REPORTED A MEASURED WIND GUST OF 56 MPH.

&&

KLG

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

MTZ008-015-102100-
Madison MT-Beaverhead MT-
228 PM MDT MON JUL 10 2017

...SIGNIFICANT WEATHER ADVISORY FOR WESTERN MADISON AND NORTH CENTRAL
BEAVERHEAD COUNTIES UNTIL 300 PM MDT...

At 228 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from 10 miles northeast of Wisdom to 14 miles
northeast of Jackson. Movement was northeast at 40 mph.

Nickel size hail and wind gusts up to 50 mph will be possible with
these storms.

Locations impacted include...
Wise River, Melrose and Dewey.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 4581 11343 4575 11336 4580 11335 4582 11328
      4587 11322 4588 11310 4581 11300 4576 11277
      4570 11275 4568 11270 4563 11270 4566 11260
      4559 11252 4538 11318 4577 11347
TIME...MOT...LOC 2028Z 235DEG 35KT 4574 11332 4547 11314

KJ

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

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

0153 PM     TSTM WND GST     12 NNE CHECKERBOARD     46.72N 110.41W
07/10/2017  M52 MPH          JUDITH BASIN       MT   MESONET

            SOUTH FORK JUDITH RAWS REPORTED A WIND GUST OF 52 MPH.

&&

KLG

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

MTZ008-015-102100-
Madison MT-Beaverhead MT-
247 PM MDT MON JUL 10 2017

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN MADISON AND NORTH
CENTRAL BEAVERHEAD COUNTIES UNTIL 300 PM MDT...

At 246 PM MDT, Doppler radar was tracking a strong thunderstorm 18
miles north of Dillon, moving northeast at 10 mph.

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

Locations impacted include...
Twin Bridges and Glen.

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.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4569 11275 4568 11270 4563 11270 4563 11267
      4568 11258 4569 11253 4556 11222 4526 11278
      4536 11300
TIME...MOT...LOC 2046Z 222DEG 8KT 4548 11273

Moldan

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

MTZ008-015-052-102145-
Madison MT-Beaverhead MT-Jefferson MT-
300 PM MDT MON JUL 10 2017

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN MADISON...NORTH
CENTRAL BEAVERHEAD AND SOUTH CENTRAL JEFFERSON COUNTIES UNTIL 345 PM
MDT...

At 300 PM MDT, Doppler radar was tracking a strong thunderstorm 17
miles north of Dillon, moving northeast at 35 mph.

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

Locations impacted include...
Sheridan, Whitehall, Twin Bridges, Silver Star, Pony, Melrose,
Waterloo and Glen.

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 4571 11275 4570 11275 4568 11270 4564 11271
      4563 11267 4570 11253 4576 11250 4575 11219
      4586 11243 4590 11241 4603 11216 4560 11182
      4521 11283 4553 11307
TIME...MOT...LOC 2100Z 239DEG 32KT 4546 11274

KJ

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

MTZ052-053-055-102200-
Broadwater MT-Jefferson MT-Gallatin MT-
313 PM MDT MON JUL 10 2017

...SIGNIFICANT WEATHER ADVISORY FOR SOUTH CENTRAL BROADWATER...
EASTERN JEFFERSON AND NORTHERN GALLATIN COUNTIES UNTIL 400 PM MDT...

At 311 PM MDT, Doppler radar was tracking a strong thunderstorm near
Three Forks, or 31 miles south of Townsend, moving northeast at 30
mph.

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

Locations impacted include...
Three Forks, Manhattan, Logan, Maudlow, Trident, Willow Creek,
Menard, Madison Buffalo Jump State Park and Missouri Headwaters State
Park.

LAT...LON 4575 11166 4591 11178 4621 11125 4585 11091
TIME...MOT...LOC 2111Z 243DEG 28KT 4587 11163

KLG