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Area forecast discussion...updated 
National Weather Service Billings Montana
905 PM MDT Sat Apr 25 2015

lower probability of precipitation across the central zones tonight. Models and radar do
not show much of anything outside of the mountains until the early
morning hours. There should be sufficient cloud cover to keep any
fog from forming from Miles City east. Sref probabilities are not
very high for fog and hrrr is not showing much have
not added any for to the forecast. Reimer &&

Short term...valid for sun and Monday...

Upper trough and disturbance that brought the rain and rain/snow
mix overnight to our central and western areas overnight and this
morning will continue to shift north and east for the remainder of
this afternoon. Area of light rain has mostly moved into Rosebud
County with movement mainly northward. Have shifted likely probability of precipitation
from our central areas to our far eastern areas for this evening
and kept a high scattered shower chance elsewhere as radar is
showing some shower activity moving off the beartooth foothills.
Areas from Big Horn County to Yellowstone and Wheatland counties
will see a break in the showers this afternoon as the activity
will be more isolated in nature. However...this will be short-
lived as the next system will quickly moves into the area tonight.

A large trough and upper low currently moving onto the Pacific
northwest coast will into the central and northern rockies late
tonight and Sunday. The strongest dynamics still look to remain to
our south but not as far south as the past couple of days have
indicated. Models keep the bulk of the heaviest precipitation across
Wyoming but latest models shift some of this further north across
our far southern areas. Will still continue to bring in likely
probability of precipitation late this evening through Sunday morning across all but the
far northern portions of our forecast area. The strongest dynamics
and associated cooling still look to stay to our south but models
do bring a bit more colder air into the mountain and foothills
locations. This will result in the possibility of some snow for
the Red Lodge area late tonight into Sunday morning with the
possibility of an inch or two of accumulation with a cold rain
further east across the adjacent plains.

Likely probability of precipitation will continue all day Sunday with the precipitation slowly
shifting east into the Dakotas by evening leaving just a chance
for showers across the area. The exception will be out toward the
Dakota borders where likely probability of precipitation will continue through Sunday
night. We may see around 4 to 7 inches of snow accumulation for
the higher elevations of the beartooth/absaroka and Big Horn
Mountains from tonight into Monday morning.

Conditions begin to dry out by Monday as high pressure ridging
begins to build across the northern rockies. Temperatures Sunday
will be quite chilly especially combined with the showers and rain
with readings only in the lower to middle 50s.
However...temperatures around normal will return for Monday with
lower 60s common. Hooley

Long term...valid for Tuesday...Wed...Thu...Fri...Sat...

Little in the way of changes again for extended forecast period.
Models remain in pretty good agreement throughout. There are a few
timing issues late in the period... but is to be southwest
flow sets up and multiple shortwaves cross thing the region.

A strong upper level ridge will dominate the pattern to begin the
period...bringing sunny and dry conditions to the region. Temperatures
will climb into the middle 70s Tuesday and around 80 in most
locations on Wednesday. Ridging gives way to southwest flow aloft
on Wednesday a deep trough develops along the West Coast.
This pattern will persists through the end of the extended
period...bringing Pacific moisture and multiple shortwaves across
the region. Nothing appears significantly strong to hang our hat
on at this point...but showers will be a possibility throughout
the last half of the period. Cloud cover and showers should keep
temperatures a bit cooler...but still in 70s across the region. Aag



A few showers are possible west of kbil through 06z...otherwise rain
and snow showers will move into the western mountains and
foothills well as into the NE bighorns. Rain
showers will overspread the entire area on sun with rain and snow
showers over and near the foothills. Expect MVFR/IFR conditions
with the precipitation tonight and Sun. Mountain obscurations will
increase tonight and be widespread on sun. Arthur

Preliminary point temp/pops...

Sun Monday Tuesday Wednesday Thursday Friday Sat
bil 038/052 037/062 041/076 048/080 048/073 049/075 048/070
36/r 31/b 00/u 01/u 12/west 22/west 22/west
lvm 035/050 030/062 035/073 044/076 043/069 042/070 041/062
67/r 31/b 00/u 01/u 13/west 22/west 22/west
hdn 037/056 037/064 039/076 047/081 048/075 050/078 049/071
26/r 41/b 00/u 00/u 12/west 22/west 22/west
mls 037/056 038/064 040/075 047/081 049/075 051/078 050/071
24/r 41/b 00/u 00/u 11/u 22/west 22/west
4bq 037/052 038/060 037/072 045/079 047/076 048/078 050/072
38/r 72/west 00/u 00/u 02/west 22/west 22/west
bhk 036/053 037/057 038/070 044/075 046/072 048/076 050/070
37/r 83/west 00/u 00/u 11/u 22/west 22/west
shr 037/049 034/060 037/071 042/075 045/072 046/074 046/068
47/r 62/west 00/u 00/u 11/u 22/west 22/west


Byz watches/warnings/advisories...



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