Area Forecast Discussion
Issued by NWS Billings, MT
FXUS65 KBYZ 132201
Area Forecast Discussion
National Weather Service Billings MT
401 PM MDT Thu Oct 13 2016
.SHORT TERM...valid for Tdy and Fri...
Powerful jet stream heading into the Pacific Northwest will bring
a windy pattern to the western half of the forecast area with
moisture for the mountains. Temperatures will be above normal
through the period and any moisture that reaches the lower
elevations will be light.
Winds already sustained above 25 mph at KLVM and approaching
energy is going to tighten pressure gradients this evening.
Pressure gradients between KLWT and KIDA are expected to double
overnight and local guidance strongly supports wind gusts in
excess of 60 mph later tonight into early Friday along the I90
corridor west of Big Timber including Livingston and also over the
Stillwater River. Current advisory looks good and bigger question
is whether strong winds will impact other areas. Looking at hi res
guidance HRRR ARW and NMM all want to restrict mountain wave
activity to higher elevations overnight and early Friday.
One concern is 70 to 80 kt winds progged at 700mb but pressure
gradients are oriented southerly with this pattern which is
supported by the surface low generating the winds later tonight
moving north northeastward from northwest Montana into Alberta as
opposed to a more easterly track. Will not spread wind highlights
to other areas though would expect very strong mountain winds
Heights fall throughout the day on Friday but downslope is a big
factor for the lower elevations. Snow will fall in the mountains
but snow ratios should be fairly low and expect periods of showers
combined with orographics to be the main reason for accumulation
but these will be short bursts. Drier conditions begin to dominate
the plains Friday night into Saturday with lighter winds for a
generally fall day. borsum
.LONG TERM...valid for Sat...Sun...Mon...Tue...Wed...
A progressive flow will prevail over the region during the
extended period, with moist westerly flow and unsettled pattern
moving into the mountains.
Strong ascent moves into the mountains on Sunday and spreads over
the Plains. Dry air will limit shower development from spreading
eastward to the Plains, however likely PoPs over the Beartooths is
expected with transition to snow in the high country during the
Pattern remains cool and unsettled with the biggest threat for
precip away from the foothills on Monday as a vigorous front
moves through the area. Gusty wind potential on Sunday/Monday due
to this front as it moves through the Harlowton area.
Seasonable temps with foothills pop chances continue through mid-
week with westerly/northwesterly flow prevailing. Walsh
VFR conditions will prevail today and tonight. Wind shear
concerns after sunset at LVM. These stronger winds will begin to
work down to the surface overnight with wind gusts increasing to
45-50 kts late tonight. Walsh
.PRELIMINARY POINT TEMP/POPS...
Tdy Fri Sat Sun Mon Tue Wed
BIL 062 049/069 045/064 048/066 046/061 041/056 039/056
0/U 01/B 21/B 12/W 24/W 31/B 22/W
LVM 065 050/062 042/061 045/060 044/055 038/050 036/053
0/N 04/W 32/W 33/W 35/W 32/W 22/W
HDN 062 043/072 045/066 045/068 044/063 040/057 037/057
0/U 01/E 21/B 12/W 13/W 32/W 12/W
MLS 063 042/072 046/067 045/067 045/061 040/057 038/056
0/U 01/E 11/B 11/B 12/W 31/B 12/W
4BQ 067 042/075 046/067 045/072 045/066 040/058 037/058
0/U 00/B 11/B 11/B 12/W 21/B 12/W
BHK 064 040/073 044/064 043/067 042/062 038/054 034/054
0/U 00/B 11/B 11/B 12/W 31/B 11/B
SHR 065 044/073 043/065 041/067 042/063 037/055 034/056
0/U 00/B 11/B 11/B 12/W 22/W 12/W
MT...Wind Advisory in effect from 9 PM this evening to 9 PM MDT
Friday FOR ZONES 65-66.