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The following presentation is the Annual Climate of the Northern Rockies for the year 2012.
A few highlights from 2012. First a snowy winter season. Second there were some significant
severe weather in the spring. Third and the greatest impact this past year was the Record
Dry Summer and Fall which helped produce a very active Wildfire Season.
The winter season for 2012 encompasses the season, from October 2011 through spring 2012.
This graph represents snowfall for the season of October 2011 through June 2012. Missoula
received 39.1" of snow which is right at normal. Kalispell had it's 2nd lowest snowfall
on record of 31.3" The lowest snowfall amount on record is 14.6" in winter 1943-1944
Two of the greatest snowfall amounts in one day occurred in 2012. Records are taken since
1948 at the Missoula Airport. January 18th 2012 8.6" fell which is the 9th greatest
one day snowfall on record. December 7, 2012 8.0" fell at the Missoula Airport which
ranks 12th as the highest one day snowfall. We will move forward to significant weather
events in spring 2012. On June 4th a strong thunderstorm produced
hail that covered the ground about 1 inch deep for a short time.
On June 24th a very strong thunderstorm produced rain and hail but most significantly wind
gusts close to 80 mph in and around the vicinity of the the Missoula Airport. This picture
was taken from the Missoula Weather Office. One of the driest summers and Autumns on record
aided in the explosive wildfire season across the Northern Rockies.
What caused this unusual dry spell was a large upper ridge of high pressure across much of
the west. This ridge prevented any weather system from moving through the region. As
well it produced very strong inversions which limited visibilities from all the smoke from
wild fires. All of this smoke also impacted the region by producing widespread air quality
or health concerns. The lack of precipitation from mid July through
late August produced a short term drought in the Northern Rockies. Note that Kalispell
and Missoula were around 1 to 2 inches below normal.
Very little precipitation occurred in August across the entire Northern Rockies. Listed
are a few locations. September was even a drier month with several
stations receiving little if any rainfall. This was one of the driest months on record
with stations recording all time low precipitation values.
The combination of both August and September recorded some of their lowest amounts on record.
Note the photos on the bottom. The very dry fuels combined with a few August thunderstorms
their lightning produced numerous forest fires in the region. The large are of high pressure
stabilized the atmosphere, essentially putting a lid on the region and not allowing smoke
to disperse. As a result much of the Northern Rockies looked like the photo on the right
during the entire day. Another notable record was how many days in
a row areas received NO precipitation. From around a month to over 2 months some areas
did not receive rain which further complicated or caused heavy smoke to linger in valley
locations. This impacted health concerns. This is a satellite picture of all the smoke
in the valleys of the Northern Rockies, notably central Idaho and the Bitterroot and Missoula Valleys.
Last we will look at some Annual Statistics for 2012
Precipitation across the Northern Rockies for the entire year were generally above normal
in Northwest and West Central Montana YET well below normal in Southwest Montana and
Central Idaho. Average Temperatures were well above normal
across the entire Northern Rockies, in fact in the top 10 readings since records were
taken in 1948. Average temperature records are taken from 1948 due to inaccuracies before.
This has been a presentation from the National Weather Service in Missoula, Mt. Have a great
2013