Area Forecast Discussion
Issued by NWS Billings, MT
FXUS65 KBYZ 261606
Area Forecast Discussion...Updated
National Weather Service Billings MT
1006 AM MDT Sun Mar 26 2017
Main push of Pacific moisture is exiting the area to the east this
morning after depositing up to 10 inches of snow in the Bighorn
mountains and up to half an inch of precipitation across our
southern zones from Sheridan county east into Carter county
overnight. There is a weak disturbance crossing the area further
west this morning resulting in some clouds/virga but don`t expect
this to amount to much, so lowered pops for the rest of the day.
Did add a mention of fog through the morning for the Tongue river
valley from Dayton north to Ashland where visible satellite
showing fog holding to the valley, this should dissipate over the
next hour. Should be very pleasant across the area this afternoon
with temperatures in the 50s to around 60 degrees, mostly sunny
skies and generally light winds. Get outside and enjoy this early
spring day. Chambers
.SHORT TERM...valid for Tdy and Mon...
Precip across the north-central Wyoming and southeastern Montana
will continue to decrease this morning as the wave exits the area.
Generally riding will dominate the weather today and Monday.
However, there is a very weak wave of energy that moves through
this afternoon. There is some slight instability with this, so
have some virga or sprinkles in the central zones. Given that the
low levels look to be dry this will most likely be just virga.
Temperatures will begin to warm today, with highs in the upper
50s. As the ridging continues Monday temperatures will again get
into the mid 60s, for much of the lower elevations.
Ahead of the next wave Tuesday some energy will start to move over
the Beartooth/Absaroka mountains. Have snow chances increasing
through the day over the higher terrain, and moving onto the
adjacent plains overnight. Reimer
.LONG TERM...valid for Tue...Wed...Thu...Fri...Sat...
Interesting/active weather through the extended period.
Tuesday is shaping up to be a fairly wet day as northern portion
of split upper trof moves slowly across the area. Models hinting
at a weak mid level circulation lifting out of WY, so am
comfortable with likely pops for our eastern zones in the
afternoon and evening. Precipitation will taper off from west to
east Tuesday night. Have adjusted temps down a few degrees in
central and east parts on Tuesday.
Wednesday should be dry with brief period of shortwave ridging
between systems. A stronger Pacific trof will emerge from the
north Pacific and drive southward thru the Pac NW to the southern
great basin Thursday and Thursday night. Strongest ascent with
this low will no doubt miss us, but we could see a period of upper
diffluence with deepened upslope flow late Thursday thru Friday,
giving us a good chance of precipitation. Must continue to stress
plenty of uncertainty as slight deviations in the track of this
low will affect our precipitation potential, and model trends
remain erratic. Tonight`s 00z runs came in fairly wet for our cwa
so have raised pops a bit more especially for western and central
upslope areas. EC actually keeps pcpn along deformation axis thru
Friday night and into Saturday, but this is a rather large change
from previous runs, so will continue to focus on Thursday
afternoon through Friday as the prime periods. Rainfall totals
over a half inch are possible, and a more favorable track of the
low could bring us an inch or more. Based on current and recent
model runs, without a significantly cold Canadian airmass to tap
into, lower elevation temps seem to be too warm for anything but
rain, but snow will fall over the mountains. Also, a heavy wet
snowfall is in the realm of possibility along our southern
foothills as 850mb temps fall to near +2C by early Friday.
Something to watch over the next few days. Again, stress the
uncertainty, as a track a bit further west would result in a non-
event for us.
However Thu/Fri pans out, we should see drying with another period
of ridging by Saturday.
To summarize temperatures next week: Tuesday will be cooler than
Monday with clouds/precipitation especially central and east
parts. Wednesday looks like the warmest day of the extended period
as ridging/downslope winds push temps back to the 60s. Thursday
is a transition day with temps warmest in our east. Friday may be
the coolest day of next week, and if a wet system materializes we
may see temps stay in the 40s. This will be followed by a warming
trend again by Saturday.
Some virga around southern MT should dissipate later this morning.
Otherwise, VFR flight conditions will prevail across the forecast
area today and tonight. Some light snow showers are possible over
the western mountains tonight, with occasional obscurations of
the Beartooth/Absarokas. RMS/Chambers
.PRELIMINARY POINT TEMP/POPS...
Tdy Mon Tue Wed Thu Fri Sat
BIL 057 038/062 040/054 037/064 042/060 039/048 035/059
1/U 11/B 56/W 10/B 14/W 66/R 21/B
LVM 053 034/055 033/055 032/061 038/056 033/048 032/057
1/B 15/W 83/W 11/B 26/W 75/O 21/B
HDN 059 037/064 038/053 033/066 038/065 037/049 033/060
1/U 11/B 46/W 20/U 12/W 66/R 21/B
MLS 059 038/066 041/059 036/066 040/065 039/052 034/060
1/U 01/B 36/W 40/B 12/W 24/R 21/B
4BQ 056 035/063 040/052 035/063 039/064 038/051 034/058
1/B 11/B 37/W 40/B 01/B 34/R 21/B
BHK 058 036/063 037/056 035/062 037/062 035/052 032/056
1/B 01/B 26/W 60/B 01/B 23/R 21/B
SHR 052 033/059 036/047 031/062 036/062 037/048 031/056
1/B 11/B 66/W 30/U 02/W 56/R 32/W