Area Forecast Discussion
Issued by NWS Billings, MT

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FXUS65 KBYZ 270911

Area Forecast Discussion
National Weather Service Billings MT
311 AM MDT Mon Mar 27 2017

.SHORT TERM...valid for Tdy and Tue...

Water vapor imagery shows weak shortwave lifting through the area
in SW flow aloft. There are some modest echoes showing up on BLX
radar to the northeast of Billings, i.e. east of surface trof.
Cloud bases are high enough such that this is likely virga or
perhaps sprinkles, but have added an isolated early morning pop.
Otherwise, our attention then turns to deeper Pacific trof which
will dig thru the Great Basin toward the 4-Corners over the next
24 hours.

Instability along inverted trof east of Billings could be a focus
of isolated showers this afternoon as daytime heating allows for
up to 100-200 j/kg of cape. Have expanded afternoon pops east to
cover this, and cannot rule out a few lightning strikes. Greater
coverage of showers, of course, will be to our west as ascent from
trof and a surface cold front move in during the late afternoon
and evening. A good chance of showers exists from west to east
across the cwa tonight and Tuesday with this trof passage, and
eastern areas will be aided by a weak circulation lifting thru WY
tomorrow. Rainfall of a quarter to half inch is expected at
Sheridan and across far SE MT. Though this system is not overly
dynamic, the combination of fairly steep mid level lapse rates and
deep/moist upslope flow should yield several inches of snow over
the Bighorn Mountains. Have issued a winter wx advisory for 5-10
inches of snow in the Bighorns from this evening to Tuesday
evening. Most lower elevations will stay as rain, but foothill
locations as low as 4500 feet could mix with wet snow late tonight
into tomorrow morning. Surface temps should stay warm enough to
prevent any real travel impacts, but reduced visibility could
occur on I-90 near Livingston and over Aberdeen Hill toward
Sheridan. Places like Red Lodge and Story could see a little
slushy accumulation.

System will track east and drying will spread in from the west
Tuesday afternoon and night.

Temperatures will be well above normal today with highs in the
upper 50s to mid 60s most places. Tuesday will be cooler of
course, with highs in the mid 40s to mid 50s, coolest down toward


.LONG TERM...valid for Wed...Thu...Fri...Sat...Sun...

Wednesday will generally be warm and dry as the area is under
ridging. Going into Thursday things will change to colder and
wetter again as the next low moves into the Intermountain West.
The GFS has continued its trend towards a wetter solution similar
to the ECMWF runs the past several days. The EC on the other hand
is taking the low farther to the southwest, with some energy
breaking off the main wave and cutting across northern Montana.
This results in less upslope into the mountains. While there would
be some precip with this solution, it would not have many
impacts. The GFS solution keeps the energy with the main wave and
places the low with better diffluent flow over southern Montana.
This solution has a better potential for some accumulating
snowfall in the mountains. Have continued to trend temps down for
Friday with the rainfall, closer to the raw consensus. For PoPs
have leaned more towards the GFS solution given that it is the
more consisten solution.

Going into the weekend things will be drying out with more
ridging across the area. Temperatures will warm back up upper 50s
to middle 60s. Early next week models have high variability so
have just gone with a blend of solutions. Reimer



VFR conditions will continue through today. This afternoon some
scattered showers will move across southern Montana which could
produce some localized MVFR conditions. Reimer



    Tdy Tue     Wed     Thu     Fri     Sat     Sun
BIL 062 041/055 035/063 041/058 040/050 034/059 038/060
    2/W 66/W    11/B    14/R    66/R    21/B    11/B
LVM 055 032/054 029/060 038/051 033/049 030/059 034/061
    5/W 83/W    11/N    26/R    75/O    21/B    12/W
HDN 064 039/053 032/064 038/061 039/051 033/060 035/062
    2/W 56/W    10/U    13/R    56/R    21/U    11/B
MLS 065 041/056 036/064 040/063 042/053 035/060 038/063
    2/W 26/W    40/B    12/R    44/R    21/B    01/B
4BQ 065 041/050 035/062 038/063 041/052 034/057 036/061
    2/W 37/W    61/B    01/B    45/R    31/B    11/B
BHK 062 037/055 036/061 037/062 039/053 033/056 034/060
    1/B 26/W    61/B    11/B    33/R    20/B    11/B
SHR 061 035/046 030/058 034/059 038/048 031/056 034/059
    1/B 68/W    20/U    13/R    66/R    31/B    10/B


WY...Winter Weather Advisory in effect from 6 PM this evening to 9
      PM MDT Tuesday FOR ZONE 98.


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