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fxus65 kbyz 181010 

Area forecast discussion
National Weather Service Billings Montana
310 am MST Mon Nov 18 2019

Short term...valid for tdy through Wed...

Winds continued to be quite gusty along the foothills west of kbil
due to the continued tight pressure gradient. Expect winds to
gradually decrease during the morning and have reflected this in
the grids. An anomalously strong upper ridge will build over the
forecast area today with mostly sunny skies and temps in the 50s
to around 60 degrees.

A Pacific trough will approach the area tonight, bringing a
slight chance of snow to the western mountains. The trough will
split as it moves into west Montana on Tuesday, bringing a cold front with
precipitation to western and northern portions of the state. There
will be a chance of morning rain and snow across the northern
forecast area, then a chance of rain over the northwest half of the area
in the afternoon. The western mountains will receive a few inches
of snow. Tuesday will be cooler with highs in the 40s to 50s.

The cold front will push through the entire area Tue. Night. And
then northern branch of the trough will cross the area through
Wednesday. There was good model agreement in the 850 mb temps
which fall below zero degs c Tue. Night. Rain will change to snow
overnight, and the nbm showed the chances for freezing drizzle
spreading a bit further west. Thus, spread freezing drizzle chances west
into Big Horn County through Wed. Morning. Snow chances will
continue over most of the area on Wednesday. Models showed some
above normal pw's over the area during this event. Qpf's will
range from a tenth /0.10/ to a quarter /0.25/ of an inch with some
spread. Mean snow amounts from the ensembles were 1 to 2 inches,
but there was some spread in these as well. For now, blended wpc
quantitative precipitation forecast with nbm quantitative precipitation forecast and got snow amounts of 1 to 2 inches N, west and S
of kbil with 4 inches in the foothills. Elsewhere had an inch or
less and had some amounts just under a foot in the western
mountains. Given the uncertainty with snow amounts and the chance
of freezing drizzle, will issue an severe weather potential statement and wx story to inform
partners of this potential. Temps on Wed. Will be in the 30s.

Long term...valid for Wed night...Thu...Fri...Sat...sun...

After a cold spell mid-week, temperatures will become mild going
into the weekend, and higher winds will make a return to south-
central Montana.

Light snow will linger in far southeast Montana Wednesday night,
but quickly move south out of the area. Sharp upper troughing will
move through the area Thursday morning, and be replace by cyclonic
flow aloft. As a deep high pressure system moves east across the
western conus, temperatures will gradually warm up by Friday and
persist through the weekend. Low pressure will gradually built
into eastern Montana, and with high pressure persisting at and
west of the northern rockies, a strong gradient looks to set up
along south-central Montana early Friday and through Saturday.
Winds along the foothills will be especially strong as Lee-side
troughing occurs during this period as well, bringing about
localized areas of low pressure to help tighten the pressure
gradients. Going into next week, heights aloft look to drastically
decrease as a strong jet sets up over the West Coast and moves

Temperatures will only reach the mid to upper 30s on Thursday, but
warm up for the weekend, reaching upwards of 50 degrees around
Billings. However, the sharp decrease in heights will bring
temperatures back to the 30s and low 40s for the beginning of next




Areas at and near klvm will continue to gust up to 45 kts through
6 am, then slowly decrease until gusting around 20 kts, still out
of the southwest. VFR will prevail over the next 24 hours. Vertz


Preliminary point temp/pops...

Tdy Tue Wed Thu Fri Sat sun
bil 059 035/051 029/035 022/038 025/048 029/050 031/048
0/u 04/r 66/S 20/u 00/north 00/b 12/o
lvm 056 038/051 028/035 018/039 023/048 026/048 027/045
0/north 07/o 65/S 10/u 00/north 00/north 12/S
hdn 058 031/051 027/036 019/039 020/048 024/050 026/049
0/u 03/r 56/S 20/u 00/u 00/u 12/r
mls 055 031/049 027/034 020/037 022/044 025/047 027/047
0/u 03/r 53/S 10/u 00/u 00/u 11/b
4bq 055 031/052 027/035 018/036 020/045 024/049 026/048
0/u 01/b 34/S 30/u 00/u 00/b 01/b
bhk 051 027/045 025/032 017/034 020/042 022/044 025/044
0/u 01/b 43/S 00/u 00/u 00/u 01/b
shr 055 029/053 025/034 015/036 015/046 021/049 022/047
0/u 01/b 37/S 50/u 00/u 00/u 01/b


Byz watches/warnings/advisories...

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