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000
FXUS65 KMSO 261040
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
340 AM MST MON JAN 26 2015

.DISCUSSION...High pressure remains over Idaho and western
Montana this morning and has helped to bring fog into stable
valley locations. Kalispell has been reporting dense fog
throughout the night as well as Salmon. These locations along with
many of the other cool valleys will see fog through this morning.
Missoula has seen frost develop instead of fog but patchy fog is
still possible through this morning from Stevensville through
Missoula.

The warm airmass aloft that has accompanied the high pressure has
left the terrain warm overnight as well as higher north-south
oriented valleys e.g., Hamilton and Deer Lodge. These locations
along with Grangeville/Camas Prairie have south winds that will
become gusty through today. Butte set a record high temperature
yesterday and is on track to break another record today.

Valleys that remain stable like Salmon will begin to see air
quality issues today and Tuesday as high pressure maintains with
fog to again be an issue for Tuesday morning.

The models are in pretty good agreement for the middle part of the
week onward. On Wednesday, a plume of moisture originating from
the Baja Mexico region will make its way up into the Northern
Rockies. This moisture will cause scattered showers over Lemhi
county into Southwest Montana. Then towards the latter part of the
week the ridge axis retrogrades back to the west causing more of a
northwesterly flow component over the Northern Rockies. This
northwesterly flow will allow for some moisture to stream into the
region, but also cause a cooler airmass to settle back over the
region. Temperatures in the higher terrain will cool. At this time
the precipitation will be fairly light, so impacts to the area
will be minimal. The models are trending towards a moist
disturbance moving into the region by the first part of next week,
but the extent of the system is unknown at this time.

&&

.AVIATION...
Fog has been an issue at KGPI and KSMN overnight and will likely
remain in place through this morning. Other stable valleys of
north central Idaho and western Montana already have fog or will
see development near sunrise. Most of the fog will lift by early
afternoon. High pressure over the region has led to a mix of
cool stable conditions or warm and mixed spots. Places like
Hamilton, Grangeville, and Deer Lodge have south winds that are
also created warm temperatures. These south and southwest winds
are being observed in the high terrain with windy downslope winds
expected along the Rocky Mountain Front through today. High
pressure will remain for Tuesday with a similar mix of fog or
wind.


&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$






000
FXUS65 KMSO 261040
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
340 AM MST MON JAN 26 2015

.DISCUSSION...High pressure remains over Idaho and western
Montana this morning and has helped to bring fog into stable
valley locations. Kalispell has been reporting dense fog
throughout the night as well as Salmon. These locations along with
many of the other cool valleys will see fog through this morning.
Missoula has seen frost develop instead of fog but patchy fog is
still possible through this morning from Stevensville through
Missoula.

The warm airmass aloft that has accompanied the high pressure has
left the terrain warm overnight as well as higher north-south
oriented valleys e.g., Hamilton and Deer Lodge. These locations
along with Grangeville/Camas Prairie have south winds that will
become gusty through today. Butte set a record high temperature
yesterday and is on track to break another record today.

Valleys that remain stable like Salmon will begin to see air
quality issues today and Tuesday as high pressure maintains with
fog to again be an issue for Tuesday morning.

The models are in pretty good agreement for the middle part of the
week onward. On Wednesday, a plume of moisture originating from
the Baja Mexico region will make its way up into the Northern
Rockies. This moisture will cause scattered showers over Lemhi
county into Southwest Montana. Then towards the latter part of the
week the ridge axis retrogrades back to the west causing more of a
northwesterly flow component over the Northern Rockies. This
northwesterly flow will allow for some moisture to stream into the
region, but also cause a cooler airmass to settle back over the
region. Temperatures in the higher terrain will cool. At this time
the precipitation will be fairly light, so impacts to the area
will be minimal. The models are trending towards a moist
disturbance moving into the region by the first part of next week,
but the extent of the system is unknown at this time.

&&

.AVIATION...
Fog has been an issue at KGPI and KSMN overnight and will likely
remain in place through this morning. Other stable valleys of
north central Idaho and western Montana already have fog or will
see development near sunrise. Most of the fog will lift by early
afternoon. High pressure over the region has led to a mix of
cool stable conditions or warm and mixed spots. Places like
Hamilton, Grangeville, and Deer Lodge have south winds that are
also created warm temperatures. These south and southwest winds
are being observed in the high terrain with windy downslope winds
expected along the Rocky Mountain Front through today. High
pressure will remain for Tuesday with a similar mix of fog or
wind.


&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$





000
FXUS65 KMSO 252128
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
226 PM MST SUN JAN 25 2015

...STAGNANT HIGH PRESSURE PATTERN TO BRING WARMER TEMPS, AIR
QUALITY ISSUES, PERSISTENT FOG...

.DISCUSSION...A massive ridge of high pressure is locked over the
western United States, and doesn`t look like it will shift enough
to allow for much change to the ongoing forecast for the next
several days. Impacts during this time will most likely be
persistent fog in locations like the I-90 corridor in western
Montana, specifically around the Missoula and south to
Stevensville. Similar to today, fog is likely to redevelop
overnight tonight and impact these areas once again Monday. In
other places, such as northwest Montana, lingering low stratus
could persist instead of fog. Many other locations across western
Montana and central Idaho could even see a mix of both.

Needless to say, not much will change in the coming
days...especially temperatures. With inversions strengthening,
upper elevations will be warming quite a bit. Some valleys will be
warming if winds are able to mix them out, causing temperatures to
rise into the 50s and even low 60s. Valleys stuck in inversions
should expect less of a warm-up, with temps in the 30s and 40s.

A low pressure system currently located along the western coast of
Baja California is forecast to shift northward and intersect a
weak shortwave trough over our region by Tuesday night/Wednesday.
The impact from this system will be minor, but it could bring some
light precipitation across the area during the mid-week. Behind
this weak system, a dry period will return for the rest of the
week into the weekend as the ridge rebuilds.

&&

.AVIATION...
Scattered mid to high clouds remain over the region today,
becoming partly cloudy to mostly clear overnight. Fairly
widespread fog development will be possible for the valleys,
especially for KMSO and KGPI after midnight. KSMN could also see
patchy dense fog in the vicinity overnight. Areas of fog that
develop are likely to remain for KGPI and KMSO through late Monday
morning.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$





000
FXUS65 KMSO 252128
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
226 PM MST SUN JAN 25 2015

...STAGNANT HIGH PRESSURE PATTERN TO BRING WARMER TEMPS, AIR
QUALITY ISSUES, PERSISTENT FOG...

.DISCUSSION...A massive ridge of high pressure is locked over the
western United States, and doesn`t look like it will shift enough
to allow for much change to the ongoing forecast for the next
several days. Impacts during this time will most likely be
persistent fog in locations like the I-90 corridor in western
Montana, specifically around the Missoula and south to
Stevensville. Similar to today, fog is likely to redevelop
overnight tonight and impact these areas once again Monday. In
other places, such as northwest Montana, lingering low stratus
could persist instead of fog. Many other locations across western
Montana and central Idaho could even see a mix of both.

Needless to say, not much will change in the coming
days...especially temperatures. With inversions strengthening,
upper elevations will be warming quite a bit. Some valleys will be
warming if winds are able to mix them out, causing temperatures to
rise into the 50s and even low 60s. Valleys stuck in inversions
should expect less of a warm-up, with temps in the 30s and 40s.

A low pressure system currently located along the western coast of
Baja California is forecast to shift northward and intersect a
weak shortwave trough over our region by Tuesday night/Wednesday.
The impact from this system will be minor, but it could bring some
light precipitation across the area during the mid-week. Behind
this weak system, a dry period will return for the rest of the
week into the weekend as the ridge rebuilds.

&&

.AVIATION...
Scattered mid to high clouds remain over the region today,
becoming partly cloudy to mostly clear overnight. Fairly
widespread fog development will be possible for the valleys,
especially for KMSO and KGPI after midnight. KSMN could also see
patchy dense fog in the vicinity overnight. Areas of fog that
develop are likely to remain for KGPI and KMSO through late Monday
morning.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$






000
FXUS65 KMSO 252009
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
109 PM MST SUN JAN 25 2015

.UPDATE...Cancelled the dense fog advisories.

&&

.DISCUSSION...Fog has lifted enough to diminish the previous
threats to travel, so the dense fog advisory for the Missoula
valley has been cancelled.

&&

.AVIATION...
Periods of low to mid level cloud ceilings are expected today,
although many areas will still see sunshine from time to time.
Shallow dense fog will be possible in the vicinity of both KGPI
and KMSO this morning. Significantly drier air aloft will move over
the relatively moist low levels tonight leading to fairly widespread
fog development across the valleys. KGPI and KMSO may see dense
fog at times by early Monday morning.

&&

.PREV DISCUSSION... /ISSUED 802 AM MST SUN JAN 25 2015/

UPDATE...Increased fog coverage and issued a dense fog advisory
for the I-90 corridor from Missoula to roughly Bearmouth, as well
as the Missoula valley south to Lolo.

DISCUSSION...Reports of dense fog have come rolling in this
morning fairly steadily, which prompted to issuance of the dense
fog advisory. It could last through the morning into early
afternoon, if winds or airmass changes do not come. With the ridge
firmly in place over the Northern Rockies, it is likely for dense
fog to reform overnight tonight once again in similar locations.
The forecast has been updated to include more fog coverage for
tonight through Monday morning.


PREV DISCUSSION... /ISSUED 341 AM MST SUN JAN 25 2015/

DISCUSSION...

Patchy dense fog will be the primary concern this morning,
occasionally leading to reduced visibilities on area roadways.
Otherwise a few light showers will be possible this morning as a
storm system exits the region with a general decreasing trend in
shower coverage throughout the day. Areas of valley fog,
potentially dense at times are expected to return tonight into
Monday morning.

Model guidance remain in agreement that high pressure and warm
air will move into Idaho and Montana tonight. The ridge over the
region will reach a peak on Monday and near record to over record
temperatures will be observed. Hamilton has a high chance to be
one of the warmer spots in the low 60s for Monday. High pressure
will weaken on Tuesday but above average temperatures will remain.

Low pressure currently on the west coast of Baja California will
move northward this week and meet with a shortwave on Wednesday
over Idaho and Montana which will further weaken the ridge and
bring the next chance for precipitation.

High pressure will remain on the west coast for the end of the
week and extended model guidance have backed off on the cold air
that was possible.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$






000
FXUS65 KMSO 252009
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
109 PM MST SUN JAN 25 2015

.UPDATE...Cancelled the dense fog advisories.

&&

.DISCUSSION...Fog has lifted enough to diminish the previous
threats to travel, so the dense fog advisory for the Missoula
valley has been cancelled.

&&

.AVIATION...
Periods of low to mid level cloud ceilings are expected today,
although many areas will still see sunshine from time to time.
Shallow dense fog will be possible in the vicinity of both KGPI
and KMSO this morning. Significantly drier air aloft will move over
the relatively moist low levels tonight leading to fairly widespread
fog development across the valleys. KGPI and KMSO may see dense
fog at times by early Monday morning.

&&

.PREV DISCUSSION... /ISSUED 802 AM MST SUN JAN 25 2015/

UPDATE...Increased fog coverage and issued a dense fog advisory
for the I-90 corridor from Missoula to roughly Bearmouth, as well
as the Missoula valley south to Lolo.

DISCUSSION...Reports of dense fog have come rolling in this
morning fairly steadily, which prompted to issuance of the dense
fog advisory. It could last through the morning into early
afternoon, if winds or airmass changes do not come. With the ridge
firmly in place over the Northern Rockies, it is likely for dense
fog to reform overnight tonight once again in similar locations.
The forecast has been updated to include more fog coverage for
tonight through Monday morning.


PREV DISCUSSION... /ISSUED 341 AM MST SUN JAN 25 2015/

DISCUSSION...

Patchy dense fog will be the primary concern this morning,
occasionally leading to reduced visibilities on area roadways.
Otherwise a few light showers will be possible this morning as a
storm system exits the region with a general decreasing trend in
shower coverage throughout the day. Areas of valley fog,
potentially dense at times are expected to return tonight into
Monday morning.

Model guidance remain in agreement that high pressure and warm
air will move into Idaho and Montana tonight. The ridge over the
region will reach a peak on Monday and near record to over record
temperatures will be observed. Hamilton has a high chance to be
one of the warmer spots in the low 60s for Monday. High pressure
will weaken on Tuesday but above average temperatures will remain.

Low pressure currently on the west coast of Baja California will
move northward this week and meet with a shortwave on Wednesday
over Idaho and Montana which will further weaken the ridge and
bring the next chance for precipitation.

High pressure will remain on the west coast for the end of the
week and extended model guidance have backed off on the cold air
that was possible.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$





000
FXUS65 KMSO 251503 AAA
AFDMSO

Area Forecast Discussion...UPDATED
National Weather Service Missoula MT
802 AM MST SUN JAN 25 2015

.UPDATE...Increased fog coverage and issued a dense fog advisory
for the I-90 corridor from Missoula to roughly Bearmouth, as well
as the Missoula valley south to Lolo.

&&

.DISCUSSION...Reports of dense fog have come rolling in this
morning fairly steadily, which prompted to issuance of the dense
fog advisory. It could last through the morning into early
afternoon, if winds or airmass changes do not come. With the ridge
firmly in place over the Northern Rockies, it is likely for dense
fog to reform overnight tonight once again in similar locations.
The forecast has been updated to include more fog coverage for
tonight through Monday morning.

&&

.AVIATION...
Periods of low to mid level cloud ceilings are expected today,
although many areas will still see sunshine from time to time.
Shallow dense fog will be possible in the vicinity of both KGPI
and KMSO this morning. Significantly drier air aloft will move over
the relatively moist low levels tonight leading to fairly widespread
fog development across the valleys. KGPI and KMSO may see dense
fog at times by early Monday morning.



&&

.PREV DISCUSSION... /ISSUED 341 AM MST SUN JAN 25 2015/

DISCUSSION...

Patchy dense fog will be the primary concern this morning,
occasionally leading to reduced visibilities on area roadways.
Otherwise a few light showers will be possible this morning as a
storm system exits the region with a general decreasing trend in
shower coverage throughout the day. Areas of valley fog,
potentially dense at times are expected to return tonight into
Monday morning.

Model guidance remain in agreement that high pressure and warm
air will move into Idaho and Montana tonight. The ridge over the
region will reach a peak on Monday and near record to over record
temperatures will be observed. Hamilton has a high chance to be
one of the warmer spots in the low 60s for Monday. High pressure
will weaken on Tuesday but above average temperatures will remain.

Low pressure currently on the west coast of Baja California will
move northward this week and meet with a shortwave on Wednesday
over Idaho and Montana which will further weaken the ridge and
bring the next chance for precipitation.

High pressure will remain on the west coast for the end of the
week and extended model guidance have backed off on the cold air
that was possible.

AVIATION...
Periods of low to mid level cloud ceilings are expected today,
although many areas will still see sunshine from time to time.
Shallow dense fog will be possible in the vicinity of both KGPI
and KMSO this morning. Significantly drier air aloft will move over
the relatively moist low levels tonight leading to fairly widespread
fog development across the valleys. KGPI and KMSO may see dense
fog at times by early Monday morning.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...DENSE FOG ADVISORY until Noon MST today Missoula/Bitterroot
     Valleys...Potomac/Seeley Lake Region.

ID...None.
&&

$$






000
FXUS65 KMSO 251041
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
341 AM MST SUN JAN 25 2015

.DISCUSSION...

Patchy dense fog will be the primary concern this morning,
occasionally leading to reduced visibilities on area roadways.
Otherwise a few light showers will be possible this morning as a
storm system exits the region with a general decreasing trend in
shower coverage throughout the day. Areas of valley fog,
potentially dense at times are expected to return tonight into
Monday morning.

Model guidance remain in agreement that high pressure and warm
air will move into Idaho and Montana tonight. The ridge over the
region will reach a peak on Monday and near record to over record
temperatures will be observed. Hamilton has a high chance to be
one of the warmer spots in the low 60s for Monday. High pressure
will weaken on Tuesday but above average temperatures will remain.

Low pressure currently on the west coast of Baja California will
move northward this week and meet with a shortwave on Wednesday
over Idaho and Montana which will further weaken the ridge and
bring the next chance for precipitation.

High pressure will remain on the west coast for the end of the
week and extended model guidance have backed off on the cold air
that was possible.

&&

.AVIATION...
Periods of low to mid level cloud ceilings are expected today,
although many areas will still see sunshine from time to time.
Shallow dense fog will be possible in the vicinity of both KGPI
and KMSO this morning. Significantly drier air aloft will move over
the relatively moist low levels tonight leading to fairly widespread
fog development across the valleys. KGPI and KMSO may see dense
fog at times by early Monday morning.


&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$






000
FXUS65 KMSO 242144
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
244 PM MST SAT JAN 24 2015

.DISCUSSION...

A relatively warm, yet weak storm system over the Northern Rockies
will dissipate through midday Sunday. Scattered light rain and
high elevation snow will be present at times, particularly across
northwest Montana during this time. Few impacts will arise
directly from this weather scenario, however the moisture left
behind will result in some patchy valley fog development across
the region on Sunday morning.

High pressure will be solidly in-place over the Northern Rockies
Monday and Tuesday, with temperatures warming greatly over the
high terrain and stagnant air settling into area valleys due to
temperature inversions. Daily overnight and morning fog will
continue to be present in valley locations. Some open plains and
southern valley locations, like Hamilton and Grangeville, will see
near-record warm temperatures on Monday.

Another relatively warm, yet weak storm system is anticipated in
bringing valley rain and mountain snow to mainly southwest
Montana and central Idaho on Wednesday. Again, the direct impacts
from this system are expected to be minimal, however the
precipitation will be conducive to fog on Thursday morning.

Some long range models suggest that an arctic airmass will be near
the Continental Divide by late Thursday night, with some very
cold air filtering into the valleys along and just west of the
Divide. Even in the event that the cold air does make it west of
the Divide, the cold event will likely be short-lived to a few
days. Confidence in the arctic airmass impacting the Northern
Rockies is low to moderate at this time.

&&

.AVIATION...
Periods of light rain are possible for the TAF sites through this
afternoon and evening and expected to taper off overnight. Low
ceilings, a slight decrease in visibility, and mountain
obscurations are possible with heavier showers. Low to mid level
cloud ceilings are expected to stick around through Sunday. Patchy
fog may be possible in the vicinity for KGPI and KMSO after
25/1200Z.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$





000
FXUS65 KMSO 242144
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
244 PM MST SAT JAN 24 2015

.DISCUSSION...

A relatively warm, yet weak storm system over the Northern Rockies
will dissipate through midday Sunday. Scattered light rain and
high elevation snow will be present at times, particularly across
northwest Montana during this time. Few impacts will arise
directly from this weather scenario, however the moisture left
behind will result in some patchy valley fog development across
the region on Sunday morning.

High pressure will be solidly in-place over the Northern Rockies
Monday and Tuesday, with temperatures warming greatly over the
high terrain and stagnant air settling into area valleys due to
temperature inversions. Daily overnight and morning fog will
continue to be present in valley locations. Some open plains and
southern valley locations, like Hamilton and Grangeville, will see
near-record warm temperatures on Monday.

Another relatively warm, yet weak storm system is anticipated in
bringing valley rain and mountain snow to mainly southwest
Montana and central Idaho on Wednesday. Again, the direct impacts
from this system are expected to be minimal, however the
precipitation will be conducive to fog on Thursday morning.

Some long range models suggest that an arctic airmass will be near
the Continental Divide by late Thursday night, with some very
cold air filtering into the valleys along and just west of the
Divide. Even in the event that the cold air does make it west of
the Divide, the cold event will likely be short-lived to a few
days. Confidence in the arctic airmass impacting the Northern
Rockies is low to moderate at this time.

&&

.AVIATION...
Periods of light rain are possible for the TAF sites through this
afternoon and evening and expected to taper off overnight. Low
ceilings, a slight decrease in visibility, and mountain
obscurations are possible with heavier showers. Low to mid level
cloud ceilings are expected to stick around through Sunday. Patchy
fog may be possible in the vicinity for KGPI and KMSO after
25/1200Z.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$






000
FXUS65 KMSO 241044
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
344 AM MST SAT JAN 24 2015

...SLICK ROADWAYS THIS MORNING DUE TO MIXED PRECIPITATION AND
BLACK ICE...

.DISCUSSION...A weak and relatively warm storm system will
continue to affect the region through early Sunday with periods
of light valley rain and high elevation snowfall. Thus far, most
valleys of northwest Montana have remained in the mid 30s
overnight limiting the freezing rain threat but freezing rain has
been reported along US-2 from West Glacier to Marias Pass.
Isolated pockets of light freezing rain remain possible this
morning thus the Winter Weather Advisories will continue as road
conditions will be changeable and slippery at times. Most mountain
passes will see a rain/snow mix this morning turning over to all
rain by late morning as snow levels rise above 6000 feet.

High pressure with significant warming in the terrain and higher
valleys can be expected Sunday through early this week. Forecast
tools that compare this upcoming high pressure with those for this
time of the year in the past point to a rare amount of warm air
for late January. This warming will make it into locations like
Grangeville, Hamilton, and Butte where record high temperatures
are possible by Monday with the peak of the warmth. Valleys like
Salmon, Missoula, and Kalispell have a higher chance to remain
stable with cool temperatures and even some fog Monday and Tuesday
mornings, which will also cause stagnant air. The ridge of high
pressure will flatten for the middle of the week which will help
cool the terrain and put an end to the exceptional warmth and
improve valley air stagnation, although, high pressure will
generally dominate the west coast through the week.

Extended model guidance are showing the potential for cooler air
from the east to clip western Montana but the westward extent of
the cold air is quite uncertain at this time.

&&

.AVIATION...An incoming weather system will bring periods of
light high elevation snow and valley rainfall to the region through
late this evening. Light freezing rain will be a threat for KGPI,
and potentially for KMSO through mid morning but overall
confidence remains low of its occurrence. Precipitation is
expected to diminish tonight but low ceilings will likely persist
into Sunday morning.



&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY until 11 AM MST this morning
     Kootenai/Cabinet Region...Lower Clark Fork Region.

     WINTER WEATHER ADVISORY until 11 AM MST this morning
     Flathead/Mission Valleys...West Glacier Region.

     WINTER WEATHER ADVISORY until 11 AM MST this morning
     Potomac/Seeley Lake Region.

ID...None.
&&

$$





000
FXUS65 KMSO 232354
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
454 PM MST FRI JAN 23 2015

.UPDATE...Corrected the winter weather advisory headlines.


&&

.AVIATION...Low stratus will be prevalent across northwest
Montana for the rest of the day, and it is likely to persist well
into the day Saturday. In addition, an incoming weather system
will spread high elevation snow and valley rainfall beginning as
early as 24/0300Z, but will become heaviest after midnight.
Freezing rain will become a threat for KGPI, and potentially for
KMSO as well, through 24/1400Z. Precipitation will spread
southward and impact the rest of western Montana and central
Idaho, with all terminals experiencing some mix of either snow or
rain. All precip types will change over to rainfall Saturday,
though low ceilings will likely persist long after the precip has
ended.


&&

.PREV DISCUSSION... /ISSUED 243 PM MST FRI JAN 23 2015/

..LIGHT SNOW BECOMING FREEZING RAIN ACROSS NORTHWEST MONTANA...
..STRONG VALLEY TEMPERATURE INVERSIONS AND STAGNANT AIR ACROSS
NORTHERN ROCKIES THROUGH NEXT WEEK...

DISCUSSION...

A weak and relatively warm Pacific storm system will impact the
Northern Rockies with light snow becoming freezing rain this
evening through midday Saturday. Travel will be impacted by sudden
icing on area roadways. Up to 3 inches of snow accumulation is
anticipated, particularly over mountain passes.

High pressure will begin to push the remaining precipitation
northward by Sunday, warming the entire Northern Rockies to
temperatures well above the seasonal average for most locales.
Temperatures will remain very warm over the terrain through at
least Tuesday, while valley locations return to temperature
inversions and stagnant air. Some locations in the southern
portion of large valleys, such as Hamilton in the Bitterroot
Valley, will experience a southerly wind on Monday and Tuesday,
warming temperatures to near 60 degrees. For many other deep
valleys, such as near Salmon Idaho, Missoula Valley, and Flathead
Valley, temperature inversions will redevelop and stagnant air
will reign. The stagnant airmass will trap air pollutants over
time, steadily decreasing air quality.

A pattern change by late next week has been recently depicted by
long range weather models, suggesting an increasingly active
pattern and less anomalous warmth.

AVIATION...Low stratus will be prevalent across northwest
Montana for the rest of the day, and it is likely to persist well
into the day Saturday. In addition, an incoming weather system
will spread high elevation snow and valley rainfall beginning as
early as 24/0300Z, but will become heaviest after midnight.
Freezing rain will become a threat for KGPI, and potentially for
KMSO as well, through 24/1400Z. Precipitation will spread
southward and impact the rest of western Montana and central
Idaho, with all terminals experiencing some mix of either snow or
rain. All precip types will change over to rainfall Saturday,
though low ceilings will likely persist long after the precip has
ended.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY from 8 PM this evening to 11 AM MST
     Saturday Kootenai/Cabinet Region...Lower Clark Fork Region.

     WINTER WEATHER ADVISORY from 8 PM this evening to 11 AM MST
     Saturday Flathead/Mission Valleys...West Glacier Region.

     WINTER WEATHER ADVISORY from 8 PM this evening to 11 AM MST
     Saturday Potomac/Seeley Lake Region.

ID...None.
&&

$$





000
FXUS65 KMSO 232354
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
454 PM MST FRI JAN 23 2015

.UPDATE...Corrected the winter weather advisory headlines.


&&

.AVIATION...Low stratus will be prevalent across northwest
Montana for the rest of the day, and it is likely to persist well
into the day Saturday. In addition, an incoming weather system
will spread high elevation snow and valley rainfall beginning as
early as 24/0300Z, but will become heaviest after midnight.
Freezing rain will become a threat for KGPI, and potentially for
KMSO as well, through 24/1400Z. Precipitation will spread
southward and impact the rest of western Montana and central
Idaho, with all terminals experiencing some mix of either snow or
rain. All precip types will change over to rainfall Saturday,
though low ceilings will likely persist long after the precip has
ended.


&&

.PREV DISCUSSION... /ISSUED 243 PM MST FRI JAN 23 2015/

..LIGHT SNOW BECOMING FREEZING RAIN ACROSS NORTHWEST MONTANA...
..STRONG VALLEY TEMPERATURE INVERSIONS AND STAGNANT AIR ACROSS
NORTHERN ROCKIES THROUGH NEXT WEEK...

DISCUSSION...

A weak and relatively warm Pacific storm system will impact the
Northern Rockies with light snow becoming freezing rain this
evening through midday Saturday. Travel will be impacted by sudden
icing on area roadways. Up to 3 inches of snow accumulation is
anticipated, particularly over mountain passes.

High pressure will begin to push the remaining precipitation
northward by Sunday, warming the entire Northern Rockies to
temperatures well above the seasonal average for most locales.
Temperatures will remain very warm over the terrain through at
least Tuesday, while valley locations return to temperature
inversions and stagnant air. Some locations in the southern
portion of large valleys, such as Hamilton in the Bitterroot
Valley, will experience a southerly wind on Monday and Tuesday,
warming temperatures to near 60 degrees. For many other deep
valleys, such as near Salmon Idaho, Missoula Valley, and Flathead
Valley, temperature inversions will redevelop and stagnant air
will reign. The stagnant airmass will trap air pollutants over
time, steadily decreasing air quality.

A pattern change by late next week has been recently depicted by
long range weather models, suggesting an increasingly active
pattern and less anomalous warmth.

AVIATION...Low stratus will be prevalent across northwest
Montana for the rest of the day, and it is likely to persist well
into the day Saturday. In addition, an incoming weather system
will spread high elevation snow and valley rainfall beginning as
early as 24/0300Z, but will become heaviest after midnight.
Freezing rain will become a threat for KGPI, and potentially for
KMSO as well, through 24/1400Z. Precipitation will spread
southward and impact the rest of western Montana and central
Idaho, with all terminals experiencing some mix of either snow or
rain. All precip types will change over to rainfall Saturday,
though low ceilings will likely persist long after the precip has
ended.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY from 8 PM this evening to 11 AM MST
     Saturday Kootenai/Cabinet Region...Lower Clark Fork Region.

     WINTER WEATHER ADVISORY from 8 PM this evening to 11 AM MST
     Saturday Flathead/Mission Valleys...West Glacier Region.

     WINTER WEATHER ADVISORY from 8 PM this evening to 11 AM MST
     Saturday Potomac/Seeley Lake Region.

ID...None.
&&

$$






000
FXUS65 KMSO 232144
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
243 PM MST FRI JAN 23 2015

...LIGHT SNOW BECOMING FREEZING RAIN ACROSS NORTHWEST MONTANA...
...STRONG VALLEY TEMPERATURE INVERSIONS AND STAGNANT AIR ACROSS
NORTHERN ROCKIES THROUGH NEXT WEEK...

.DISCUSSION...

A weak and relatively warm Pacific storm system will impact the
Northern Rockies with light snow becoming freezing rain this
evening through midday Saturday. Travel will be impacted by sudden
icing on area roadways. Up to 3 inches of snow accumulation is
anticipated, particularly over mountain passes.

High pressure will begin to push the remaining precipitation
northward by Sunday, warming the entire Northern Rockies to
temperatures well above the seasonal average for most locales.
Temperatures will remain very warm over the terrain through at
least Tuesday, while valley locations return to temperature
inversions and stagnant air. Some locations in the southern
portion of large valleys, such as Hamilton in the Bitterroot
Valley, will experience a southerly wind on Monday and Tuesday,
warming temperatures to near 60 degrees. For many other deep
valleys, such as near Salmon Idaho, Missoula Valley, and Flathead
Valley, temperature inversions will redevelop and stagnant air
will reign. The stagnant airmass will trap air pollutants over
time, steadily decreasing air quality.

A pattern change by late next week has been recently depicted by
long range weather models, suggesting an increasingly active
pattern and less anomalous warmth.

&&

.AVIATION...Low stratus will be prevalent across northwest
Montana for the rest of the day, and it is likely to persist well
into the day Saturday. In addition, an incoming weather system
will spread high elevation snow and valley rainfall beginning as
early as 24/0300Z, but will become heaviest after midnight.
Freezing rain will become a threat for KGPI, and potentially for
KMSO as well, through 24/1400Z. Precipitation will spread
southward and impact the rest of western Montana and central
Idaho, with all terminals experiencing some mix of either snow or
rain. All precip types will change over to rainfall Saturday,
though low ceilings will likely persist long after the precip has
ended.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY from 8 PM this evening to 11 AM MST
     Sunday Kootenai/Cabinet Region...Lower Clark Fork Region.

     WINTER WEATHER ADVISORY from 8 PM this evening to 11 AM MST
     Sunday Flathead/Mission Valleys...West Glacier Region.

     WINTER WEATHER ADVISORY from 8 PM this evening to 11 AM MST
     Sunday Potomac/Seeley Lake Region.

ID...None.
&&

$$





000
FXUS65 KMSO 232144
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
243 PM MST FRI JAN 23 2015

...LIGHT SNOW BECOMING FREEZING RAIN ACROSS NORTHWEST MONTANA...
...STRONG VALLEY TEMPERATURE INVERSIONS AND STAGNANT AIR ACROSS
NORTHERN ROCKIES THROUGH NEXT WEEK...

.DISCUSSION...

A weak and relatively warm Pacific storm system will impact the
Northern Rockies with light snow becoming freezing rain this
evening through midday Saturday. Travel will be impacted by sudden
icing on area roadways. Up to 3 inches of snow accumulation is
anticipated, particularly over mountain passes.

High pressure will begin to push the remaining precipitation
northward by Sunday, warming the entire Northern Rockies to
temperatures well above the seasonal average for most locales.
Temperatures will remain very warm over the terrain through at
least Tuesday, while valley locations return to temperature
inversions and stagnant air. Some locations in the southern
portion of large valleys, such as Hamilton in the Bitterroot
Valley, will experience a southerly wind on Monday and Tuesday,
warming temperatures to near 60 degrees. For many other deep
valleys, such as near Salmon Idaho, Missoula Valley, and Flathead
Valley, temperature inversions will redevelop and stagnant air
will reign. The stagnant airmass will trap air pollutants over
time, steadily decreasing air quality.

A pattern change by late next week has been recently depicted by
long range weather models, suggesting an increasingly active
pattern and less anomalous warmth.

&&

.AVIATION...Low stratus will be prevalent across northwest
Montana for the rest of the day, and it is likely to persist well
into the day Saturday. In addition, an incoming weather system
will spread high elevation snow and valley rainfall beginning as
early as 24/0300Z, but will become heaviest after midnight.
Freezing rain will become a threat for KGPI, and potentially for
KMSO as well, through 24/1400Z. Precipitation will spread
southward and impact the rest of western Montana and central
Idaho, with all terminals experiencing some mix of either snow or
rain. All precip types will change over to rainfall Saturday,
though low ceilings will likely persist long after the precip has
ended.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY from 8 PM this evening to 11 AM MST
     Sunday Kootenai/Cabinet Region...Lower Clark Fork Region.

     WINTER WEATHER ADVISORY from 8 PM this evening to 11 AM MST
     Sunday Flathead/Mission Valleys...West Glacier Region.

     WINTER WEATHER ADVISORY from 8 PM this evening to 11 AM MST
     Sunday Potomac/Seeley Lake Region.

ID...None.
&&

$$






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