Area Forecast Discussion
Issued by NWS Billings, MT

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FXUS65 KBYZ 212142

Area Forecast Discussion
National Weather Service Billings MT
342 PM MDT Tue Mar 21 2017

.SHORT TERM...valid for Wed and Thu...

Weak upper wave approaches from the west this evening. Ahead of
that wave, significant warming of the column will occur. Max
temps aloft will be around 10 Celsius which means most of the
precip over the lower terrain should be of the liquid variety.
Models aren`t crazy about PoP chances overnight over the central
and eastern Plains, but given the moisture hanging around, and a
surface low developing east of the range, there remains a chance
for isolated drizzle/light rain. Temps will be near freezing for
areas north of Forsyth and Miles City so cannot rule out a bit of
freezing rain if we are able to generate enough rainfall out of
these weak cells. Low-level moisture should be sufficient enough
to generate fog tonight from the foothills through Billings and
north to Roundup, as well as over the extreme southeastern Plains.

Much warmer day on tap for Wednesday, with highs in the low 70s
possible and dry conditions expected across most of the region.
Wednesday night a more potent low pressure system moves into
central Wyoming. Expecting half inch to an inch of rainfall with
this system from Sheridan northeastward into eastern Montana.
Although the models keep temperatures near freezing, the qpf with
this system should be enough to generate 6-10 inches of wet snow
along the eastern slopes of the Bighorns. Billings and areas
northwestward, look to stay out of the heaviest rainfall area at
this time. Walsh

.LONG TERM...valid for Fri...Sat...Sun...Mon...Tue...

Shortwave ridging should build in for Friday bringing a mainly
dry day to the area. Then the pattern turns unsettled. Two
shortwave troughs will move through the region Saturday into
Sunday, bringing some light rain to the region.

Shortwave ridging returns for Sunday night, giving a break in the
rain. Additional shortwaves look to move through the region early
next week, producing more periods of light rain. Models differ on
the timing of a trough on Monday...if the GFS is right Monday
could end up being a mostly dry day. The ECMWF and GFS agree on an
upper trough somewhere over the western U.S. for Tuesday, a
scenario suggesting another chance of rain.

High temperatures across the lower elevations will range from the
50s to 60s through the extended, with the warmest days being
Friday and Saturday.  RMS/Walsh



Low clouds and MVFR-IFR over south central MT and north central
WY will persist through this evening. Surface winds should shift
to southwesterly after midnight for KBIL-KLVM, helping to scour
out the low clouds. A few showers are possible this evening and
overnight, bringing temporary LIFR conditions. Mountains will be
obscured tonight. RMS/Walsh



    Wed     Thu     Fri     Sat     Sun     Mon     Tue
BIL 038/068 041/058 036/063 041/061 038/057 037/057 037/054
    21/B    25/W    20/U    12/W    33/W    13/W    33/W
LVM 038/065 034/056 031/060 039/058 033/055 033/055 033/053
    32/L    34/W    11/U    14/W    44/W    23/W    33/W
HDN 034/071 039/060 033/065 037/064 036/058 035/059 035/056
    21/B    35/W    30/U    02/W    33/W    13/W    33/W
MLS 034/069 040/061 035/063 038/064 039/059 036/058 036/054
    22/L    24/W    20/U    01/B    33/W    12/W    33/W
4BQ 034/071 041/056 035/061 036/064 037/058 036/057 036/053
    20/B    37/W    30/U    00/B    33/W    12/W    45/W
BHK 031/062 036/057 032/059 033/061 036/055 032/054 032/050
    22/S    16/W    20/U    00/B    33/W    12/W    24/W
SHR 036/068 039/053 033/061 034/062 036/057 033/056 034/054
    21/B    68/W    50/U    01/B    43/W    13/W    43/W




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