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fxus65 kbyz 181532 

Area forecast discussion...updated
National Weather Service Billings Montana
932 am MDT Wed Sep 18 2019

only changes for the update were to increase winds this morning
over the far eastern zones, as winds were gusty behind the system
north of the ND/Canadian border, and to reduce rh's central and west
based on rap soundings. Otherwise, expect dry forecast through
tonight. Arthur


Short term...valid for tdy and Thu...

The system that brought showers and scattered thunderstorms to
the forecast area on Tuesday, was working across western North
Dakota early this morning. Wrap around showers were giving a
glancing blow of precipitation at Baker, but these showers will
taper off by forecast issuance time. A small scale ridge was in
the process of building in for a dry period today and tonight.
Highs today will be able to rebound into the 70s with less cloud
cover. A deepening upper trough will work toward the Great Basin
tonight. This process has slowed, so have removed pop mention for
the far west tonight. Twh

On Thursday, an upper trough will move slowly eastward over the
interior west and bring in large-scale ascent to support scattered
showers and thunderstorms west of Billings. By Thursday night the
trough will have moved eastward enough to support scattered
showers and thunderstorms over the entire area of southern Montana and
northern Wyoming. A few of the storms over Fallon and Carter counties
could be strong Thursday evening with large hail and strong wind
gusts as a plume of warm, moist air extends northwestward from the
Central Plains. High temperatures will range from the 60s over
western areas to 70s in central areas and 80s over southeast Montana.

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

Upper trough will move east/northeastward over the northern
rockies Friday into Friday night and bring good large-scale ascent
over the area that supports another rain event. This system looks
like another upper low with a dry the track is
especially important for rainfall totals. It is possible that some
parts of southern Montana/northern Wyoming receive light rainfall but
others receive 0.5 inches or greater. In addition, temperatures
aloft are progged to cool enough to support accumulating snow
above 8000 feet beginning Friday afternoon. This snowfall could
impact the Beartooth Pass.

On Saturday, the upper low will move northeastward out of the
area but a weaker shortwave trough will move southeastward over
Montana. This pattern evolution will cause the steadier rain to taper
to scattered showers. Snow showers are possible in the mountains.

Upper ridging builds in for Sunday, bringing dry weather. Then
flow turns more semi-zonal with a weak shortwave trough moving
eastward and bringing isolated rain showers back to the region
(including the mountains) for Monday and Tuesday. The atmosphere
will be drier early next week so the showers would only produce
light rainfall amounts.

High temperatures will generally be in the 50s and 60s on Friday,
then 60s and 70s for Saturday through Tuesday. Rms



VFR will prevail through tonight. A few mountain obscurations are
possible Thursday morning over the west. Gusty winds at kbhk will
decrease through the day. Arthur


Preliminary point temp/pops...

Tdy Thu Fri Sat sun Mon Tue
bil 076 050/073 050/062 048/066 047/073 049/071 049/073
0/u 01/b 67/T 84/west 30/u 22/west 32/west
lvm 074 043/068 042/061 040/063 040/070 042/067 042/071
0/u 05/T 88/T 74/west 21/u 23/west 22/west
hdn 076 047/073 048/064 046/065 044/072 046/071 046/072
0/u 00/u 58/T 94/west 30/u 12/west 32/west
mls 075 050/078 052/069 049/065 046/071 047/071 048/071
0/u 00/u 44/T 85/west 30/u 11/u 21/u
4bq 076 049/084 050/069 046/064 044/071 045/072 046/071
0/u 01/u 45/T 94/west 30/u 11/u 22/west
bhk 074 051/084 052/070 047/064 044/070 045/071 046/069
0/u 01/u 45/T 75/west 31/u 01/u 11/u
shr 076 047/077 046/063 042/064 040/071 043/070 043/071
0/u 01/u 58/T 93/west 30/u 12/west 32/west


Byz watches/warnings/advisories...

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