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Area forecast discussion 
National Weather Service Great Falls Montana
1145 PM MDT Sat Oct 3 2015

Updated aviation section

a band of moderate snow has developed along a line from Rogers
Pass to Great Falls and thus have increased probability of precipitation...snow amounts
and quantitative precipitation forecast this evening. Snow accumulations up to 2 inches are
possible within this band through midnight. Roads may become snow
and slush- covered...especially bridges...overpasses and canyons
so use caution if traveling this evening. Scattered rain and snow
showers elsewhere across north central Montana will change over to
light snow showers...however any snow accumulation will be less
than a half inch on grassy surfaces. Areas along the Rocky
Mountain front will remain dry and breezy. Overnight lows will
remain steady around freezing for most areas with slightly higher
readings in the middle 30s over southwest Montana. Precipitation
should diminish Sunday morning but temperatures will remain below
seasonal averages. The remainder of the forecast is on track so no
further changes were made. Mlv


updated 0545z.
Moist upslope flow aloft will continue as will widespread rain and
snow. Conditions will slowly begin to improve after 18z. MVFR/IFR
conditions prevail due to low ceilings and precipitation. Mountains


Previous discussion...
/issued 445 PM MDT Sat Oct 3 2015/

Tonight through Monday...central and southwest Montana are
underneath a broad area of low pressure which is gradually becoming
split as a low pressure center drops south along the West Coast.
Overall flow aloft is light and dynamics weak. However, at lower
levels, moist upslope flow will continue from the north and
precipitation is expected across most of the area through the night.
Temperatures have been running a few degrees below model forecasts
and rain has been turning to snow quicker than forecast. This trend
will continue and most of the region will see at least a mix of snow
over night. The continued push of cool air into the region will drop
overnight temperatures below normals although the widespread cloudiness
will inhibit any large drops. A weak upper level shortwave will move
through the flow aloft early Sunday and the airmass will begin to
dry behind this feature. The air mass will then generally remain dry
through Monday although the closed low to the south will bring some
moisture into extreme southwest Montana. Zelzer

Monday night through Saturday...dry and mild conditions will mark
the medium range period. Zonal flow will set up over the area
through Wednesday providing dry conditions over the plains and a few
isolated mountain showers. By Thursday, an upper ridge will move to
western Montana. Short wave energy moving through the ridge position
will result in isolated showers over the Rocky Mountain front and
over the mountains of southwest Montana. The models diverge in their
solutions Friday with the GFS retrograding the ridge axis back over
the Pacific northwest while the European model (ecmwf) maintains westerly flow aloft
over the area. Dry conditions continue Saturday as 500 mb heights
rise over the area. Temperatures will be near to slightly above
seasonal averages.


Preliminary point temps/pops...
gtf 30 43 32 57 / 100 40 10 0
ctb 30 42 31 56 / 70 20 10 0
hln 35 49 35 62 / 50 30 10 0
bzn 33 50 32 63 / 50 20 10 10
wey 25 52 29 60 / 30 20 10 10
dln 31 53 34 66 / 30 20 10 10
hvr 35 45 32 56 / 100 40 10 0
lwt 32 43 33 59 / 100 40 20 10


Tfx watches/warnings/advisories...
Winter Weather Advisory until noon MDT Sunday for mtz012-014-050-




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