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Area forecast discussion...updated 
National Weather Service Billings Montana
923 am MDT Monday Oct 20 2014

an upper ridge of high pressure will dominate the weather today
providing unseasonably mild temperatures and abundant sunshine. No
changes to the current forecast. Twh


Short term...valid for today and Tuesday...

Several minor changes to the short term forecast again this
morning...with models showing improve agreement and a stronger and
more defined weather system for Tuesday and Tuesday night.

The upper level ridge will continue to shift east through the day
today and South West flow aloft will become increasingly
prevalent. Dry conditions will persist today. There will be a
shortwave sliding through the region today...but very dry
atmosphere should keep any activity from developing. Relatively
good mixing and downslope flow should push temperatures into the upper
70s in most areas.

Precipitation potential will increase for Tuesday afternoon and
especially Tuesday night however. Increased moisture and lift
will impact western zones Tuesday afternoon as energy lift out of
Idaho. The disturbance crosses the County Warning Area Tuesday night...combining
with a surface cold front...bringing increased low to middle level
lift to the system to support a better chance for showers. Did
raise probability of precipitation significantly Tuesday evening and night in response to
improved model agreement and apparent stronger and more organized
system prognosticated into the area. The cold front will push
east...bringing gusty west to northwest winds in its wake. Winds
are not expected to be terribly 850mb winds are
prognosticated at around 30kts. However...favored locations...Harlowton
to Big Timber to Livingston...will likely see slightly stronger
winds with a tight surface pressure gradient. Timing of the
disturbance for Tuesday should lend itself well to a significant
warmup ahead of the system. Did raise temperatures slightly across
central and eastern zones...with temperatures approaching 80 in some
areas. Aag

Long term...valid for Wednesday...Thu...Fri...Sat...sun...

Tuesday night shortwave will exit the area on Wednesday. Though
we could see some lingering showers mainly across our North/East
Wednesday morning...drying will occur over time with synoptic
scale subsidence and low level downsloping becoming dominant. Have
raised westerly wind speeds a bit and should see gusts on the
order of 15-20 kts. Wednesday will be quite a bit cooler than
Tuesday but with temperatures still above normal.

Thursday through Saturday will be dry with a continuation of above
normal temperatures. Only minor issue could be a weak backdoor
front on Friday...a result of a Canadian shortwave well to our
north. Otherwise expect highs mainly middle 60s to middle 70s through
this period...with high confidence for dry weather as we stay
under the influence of upper level ridging and fairly high

Models coming together now in suggesting a Pacific shortwave and
frontal passage for next trough off the coast is kicked
through The Rockies by energy from the central Pacific including
remnants of Tropical Storm Ana. This should bring a chance of
showers as well as a cool down for Sunday/Monday. Given the
Pacific flow would expect this to be rain showers at lower
elevations and some mountain snow. Have raised probability of precipitation and dropped
temperatures closer to late October normals. Jkl



Strong high pressure aloft will allow for VFR flight conditions
to prevail across the region through tonight. Jkl


Preliminary point temp/pops...

Today Tuesday Wednesday Thursday Friday Sat sun
bil 077 047/077 046/066 044/071 048/069 043/071 044/061
0/u 01/b 41/b 00/u 00/u 00/u 12/west
lvm 075 041/070 040/062 040/068 044/067 042/069 042/059
0/u 03/west 50/b 00/north 00/b 01/u 22/west
hdn 078 042/077 043/066 039/071 043/071 039/072 039/063
0/u 00/u 32/west 00/u 00/u 00/u 12/west
mls 076 041/076 045/066 041/071 044/069 041/069 041/063
0/u 00/u 32/west 00/u 00/u 00/u 01/b
4bq 077 042/079 045/064 038/070 042/071 040/071 042/063
0/u 00/u 22/west 00/u 00/u 00/u 01/b
bhk 073 038/076 044/063 037/068 041/067 038/066 039/060
0/u 00/u 12/west 00/u 00/u 00/u 01/b
shr 079 038/079 040/065 034/072 039/073 037/073 038/064
0/u 00/b 22/west 00/u 00/u 00/u 02/west


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