Red Flag Warning 11, NWS Great Falls, MT

543 
WWUS85 KTFX 131916
RFWTFX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Great Falls MT
116 PM MDT Sun Aug 13 2017

...Increased Fire Danger Associated with a Cold Front Today...

MTZ112>118-140300-
/O.CON.KTFX.FW.W.0011.000000T0000Z-170814T0300Z/
Eastern Glacier/Toole/Central/Eastern Pondera/Liberty-
Hill and Blaine Counties-
Lewis and Clark National Forest Rocky Mountain District-
Rocky Mountain Front-Chouteau and Fergus Counties-
Lincoln Ranger District of the Helena National Forest-
Central and Eastern Lewis and Clark National Forest Areas-
Helena and Townsend Ranger Districts of the Helena National Forest-
116 PM MDT Sun Aug 13 2017

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT THIS
EVENING...

* IMPACTS: A wind shift with a cold front and increasing
  thunderstorm activity will create erratic fire behavior and an 
  increased risk of new fire starts. 

* AFFECTED AREA: 
  In North Central Montana Fire Zones...112...113...114...115
                                        117.
  In Southwest Montana Fire Zones...116...118.

* COUNTIES AFFECTED: 
  In Central Montana, Cascade, Fergus, Judith Basin
                       Lewis and Clark, Meagher.
  In North Central Montana, Blaine, Chouteau, Glacier, Hill
                             Liberty, Pondera, Powell, Teton,
Toole.
  In South Central Montana, Golden Valley, Park, Phillips
                             Sweet Grass, Wheatland.
  In Southwest Montana, Broadwater, Gallatin, Jefferson.

* COLD FRONT: The cold front is expected to reach fire weather
  zones 112, 114, 116, 118, and the western half of 117 between
  1300 and 1600 MDT this afternoon. The front will reach fire
  weather zones 113, 115, and the eastern half of 117 between 1500
  and 2000 MDT Sunday afternoon and evening.

* WIND: South 10 to 20 mph, becoming west 10 to 20 mph with gusts
  to 30 mph behind the front. The wind will gradually subside a 
  few hours after the front passes.

* THUNDERSTORMS: Isolated to scattered thunderstorms, some dry, are
  expected with the front through this evening. The greatest
  coverage of thunderstorms is expected across fire weather zones
  113, 115, and 118.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions are
either occurring now, or will shortly. A combination of gusty winds
and increased lightning activity associated with a cold front can 
contribute to extreme fire behavior.

Please advise the appropriate officials or fire crews in these
areas of this Red Flag Warning.

&&

$$

http://weather.gov/greatfalls

MARTIN

002 
WWUS85 KTFX 140306
RFWTFX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Great Falls MT
906 PM MDT Sun Aug 13 2017

MTZ112>118-140415-
/O.EXP.KTFX.FW.W.0011.000000T0000Z-170814T0300Z/
Eastern Glacier/Toole/Central/Eastern Pondera/Liberty-
Hill and Blaine Counties-
Lewis and Clark National Forest Rocky Mountain District-
Rocky Mountain Front-Chouteau and Fergus Counties-
Lincoln Ranger District of the Helena National Forest-
Central and Eastern Lewis and Clark National Forest Areas-
Helena and Townsend Ranger Districts of the Helena National Forest-
906 PM MDT Sun Aug 13 2017

...RED FLAG WARNING HAS EXPIRED...

Thunderstorm activity has diminished across most of the Warning 
area, and relative humidities have recovered mostly into the 60 to
65 percent range as winds behind the cold front have decreased.
Therefore, the Red Flag Warning has been allowed to expire.

However, the cold front has not completely exited the fire
districts as of 9 pm MDT, as it has yet to move completely through
Blaine County. Showers and thunderstorms associated with the cold
front will likely produce erratic wind gusts in excess of 35 mph,
but there has been enough rainfall with the storms to cause
humidity to recover quickly. This will help lessen the threat for
critical fire weather conditions there.

$$

http://weather.gov/greatfalls

Area Forecast Discussion
National Weather Service Great Falls MT
1213 AM MDT Sun Aug 13 2017

Early Morning Update

.UPDATE...

Convective activity over Beaverhead County has blossomed in the last
hour or two, which has resulted in expanding PoPs/QPF a bit quicker
northeast through the overnight and morning hours. This is in
association with a pronounced upper-level wave, a 700-mb warm
frontal signature which represents the leading edge of rapidly
increasing mid-level moisture, and sufficient instability for
isolated to scattered showers and thunderstorms. Will continue to
monitor trends through the night and make adjustments as necessary.
CC

&&

.SYNOPSIS...

Isolated thunderstorms will move slowly southeast over the
mountains through this evening. Later tonight, at least a slight
increase in showers and thunderstorms is possible, especially
across Southwest Montana. A cold front will then bring an
increasing chance of thunderstorms areawide Sunday afternoon and
evening, along with breezy conditions. The wind will likely bring
smoke into the area from fires around the region.

&&

.AVIATION...
Updated 0410Z.

VFR conditions are expected for much of the period, but MVFR
conditions are possible with showers and thunderstorms Sunday
afternoon. Wildfire smoke will lower visibility slightly across much
of southwest Montana into Sunday. A disturbance will begin to break
down the ridge and bring increasing mid level clouds with a chance
of mainly mountain showers through 15Z. Another disturbance with an
associated Pacific cold front will then move east through the
forecast area between 18Z and 00Z. This will spread scattered
showers and thunderstorms, along with some additional wildfire
smoke, across the forecast area. Storms may produce wind gusts up to
40 kt and brief heavy rain with MVFR ceilings, while some of the
stronger storms could produce hail. Storms will then decrease from
the west after 21Z through 06Z.
Coulston

&&

.FIRE WEATHER...

The main concern over the next 24 to 36 hours is increased
thunderstorm activity followed by a cold front with gusty winds.
Isolated dry thunderstorms will mainly be confined to the
mountains through this evening, possibly with an increase in
coverage across SW MT overnight. Thunderstorm activity then looks
to increase across all TFX fire weather zones Sunday afternoon and
early evening as a front pushes through. While RH doesn't look
critically low on Sunday, the increased lightning activity
followed by gusty winds with the front is certainly concerning.
And, some thunderstorms will likely be dry. For these reasons, we
have decided to issue a Fire Weather Watch for all TFX fire zones
(112-118) to highlight the potential of elevated to critical fire
weather conditions with the passage of the front. Beyond this
weekend, drier conditions are expected along with near normal
temperatures. MARTIN

&&

.PREV DISCUSSION...
/ISSUED 640 PM MDT Sat Aug 12 2017/

Rest of today through Sunday night...A drier NW mid/upper flow has
developed across the area this afternoon in the wake of the
departing upper low that is currently spinning over eastern MT. This
and some smoke in the area looks to limit thunderstorm activity for
the rest of this afternoon. That said, I still expect a few
showers/storms to develop along the Rocky Mtn Front and across far
SW MT, especially downwind of NW facing slopes.

Attention then turns to the tonight through Sunday night period. A
lead shortwave moves through tonight with increasing moisture and
somewhat better lift. Short term guidance offers various solutions
on the evolution of showers/storms tonight. With the increase in
moisture/lift, it is hard to ignore the potential of a band or two
of storms moving through, but I kept pops somewhat lower for now.
Showers may be ongoing or pushing out of the area Sunday morning and
this will be followed by a cold front that will sweep east through
the area Sunday afternoon. While there should be a decent amount of
mid/upper level moisture along with greater lift, it is unclear what
impact, if any, clouds/showers Sunday morning will have on afternoon
storms. Thinking is that at least weak instability is likely with
daytime heating and scattered showers/storms are expected along the
front. The main threat looks to be gusty winds associated with
showers/storms as well as with the front, itself. The westerly wind
will likely bring smoke into the area from fires along/west of the
Continental Divide. By Sunday night, the front stalls some over SW
MT and with lingering moisture/lift, thinking showers and isolated
thunderstorms will continue into the night there. MARTIN

Monday through Saturday...The main upper level trof will be exiting
the region on Monday with storms mainly confined to the eastern
sections of the region. For Tue through Friday...fairly quiet
weather conditions are expected over the region. The flow aloft will
be westerly on Tue and gradually transition to an upper level ridge
by next Friday. On Saturday...the GFS progs a weak upper level
disturbance moving into Southwest MT...but confidence is low in that
feature at this time. Expect slightly below normal, but still very
comfortable afternoon temperatures for Tue through Thursday, with a
gradual warming trend to slightly above normal afternoon
temperatures by late next week. Brusda

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  57  85  54  78 /   0  50  40  10
CTB  54  81  50  76 /   0  30  20  10
HLN  57  82  55  79 /  20  40  40  10
BZN  53  83  52  76 /  20  40  50  30
WEY  43  75  42  68 /  20  30  40  30
DLN  52  79  50  76 /  20  40  40  20
HVR  57  89  57  81 /   0  20  40  10
LWT  55  83  54  75 /   0  30  40  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Sunday afternoon through Sunday evening
Central and Eastern Lewis and Clark National Forest Areas...
Chouteau and Fergus Counties...Eastern
Glacier/Toole/Central/Eastern Pondera/Liberty...Helena and
Townsend Ranger Districts of the Helena National Forest...Hill
and Blaine Counties...Lewis and Clark National Forest Rocky
Mountain District-Rocky Mountain Front...Lincoln Ranger District
of the Helena National Forest.

Red Flag Warning until 9 PM MDT Sunday Deerlodge/Western
Beaverhead National Forest...Eastern Beaverhead National Forest.

&&

weather.gov/greatfalls