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Area forecast discussion 
National Weather Service Billings Montana
240 PM MDT Tuesday Sep 16 2014

Short term...valid for Wednesday and Thursday...

Ridge aloft will be over the area for the next couple of days.
This will keep above normal temperatures and mainly dry conditions
in place. There will be enough middle level moisture around to bring
a few thunderstorms to area mountains each afternoon and evening.
By later in the day Thursday a Pacific trough will begin to
influence the area. Monsoonal moisture drawn northward into the
area ahead of the trough will provide the fuel for increasing shower
and thunderstorm coverage Thursday night and Friday. Precipitable
water values around an inch...which is significantly above
normal...over the area will bring the potential for some heavy
rainfall rates with any storms that do form. Kept precipitation
chances in the 30 to 50 percent range for now but may need to bump
these up in some areas as the system gets closer. Cold front
sneaks in under the upper trough on Friday and will bring more
seasonal temperatures for the weekend. Chambers

Long term...valid for Friday...Sat...sun...Mon...Tue...

Middle Range models in good agreement through the weekend. Dry
northwesterly flow will be in place Saturday as West Coast ridge
drifts eastward toward the area. By Sunday and Monday the ridge
will be in place over Montana for warmer and mainly dry
conditions. Models are all grabbing onto a piece of energy that
drifts northward under the ridge from California and into the
central rockies by late Monday. A few models drag this energy into
southern Montana Tuesday and Wednesday while others kick it east.
With this system being under the broad upper ridge it wouldn't be
a big precipitation maker but would result in a chance for
afternoon and evening storms. Kept dry forecast for now through
the middle of next week but will watch this energy closely and may
need to increase probability of precipitation if models continue to drag it into the area.
Temperatures will be mainly in the 70s Saturday through much of
next week...with a few 80s Monday and Tuesday. Chambers



VFR conditions will prevail tonight. Isolated early evening
thunderstorms over western mountains will dissipate quickly with
sunset. Local MVFR conditions can be expected near any storms.


Preliminary point temp/pops...

Wednesday Thursday Friday Sat sun Monday Tuesday
bil 056/085 058/085 058/076 050/074 048/077 047/078 052/077
01/b 12/T 33/T 20/u 00/u 01/u 11/u
lvm 051/087 053/082 050/074 041/075 042/077 042/076 045/076
12/T 23/T 33/T 20/u 00/u 00/u 01/u
hdn 051/086 053/088 056/078 049/076 047/078 046/079 048/078
01/b 11/b 33/T 20/u 00/u 01/u 11/u
mls 051/085 056/088 058/078 050/075 046/078 047/078 048/078
00/b 02/T 23/T 20/u 00/u 01/u 11/u
4bq 051/086 055/090 058/077 050/074 046/078 046/078 047/078
00/b 11/b 23/T 20/u 00/u 01/u 11/u
bhk 047/082 052/085 057/076 049/074 043/075 044/077 045/075
00/b 02/T 23/T 20/u 00/u 01/u 11/u
shr 051/085 053/087 054/075 046/073 043/075 041/075 043/075
11/b 11/b 24/T 30/u 01/u 11/u 11/u


Byz watches/warnings/advisories...



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