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Area forecast discussion 
National Weather Service Billings Montana
321 am MDT Thursday may 28 2015

Short term...valid for today and Friday...

The low that has been over eastern Washington and western Idaho
will move southeast through the day. This will take the low across
western Montana and into Wyoming. This will bring more of the main
troughs energy across the area. Conditions across the area today
will be very similar to yesterday. Precipitable water values will
continue to be in the three quarters to one inch range. With more
energy and instability across the area...showers will be a little
more widespread. There will again be some cape across the some isolated thunderstorms will be possible across
mainly this afternoon.

Tonight a weak front will move south out of Canada into Montana.
Behind the front winds will shift to out of the north.
Temperatures will be slightly cooler during the day tomorrow...a
couple of degrees lower than today. Upper level flow will become
more westerly as a Flat Ridge begins to build in from the west.
Rain chances will slowly decrease through the day as the ridge
move in. As the ridge will be flat...some rain chances will remain
over the mountains. Reimer

Long term...valid for Sat...sun...Mon...Tue...Wed...

Extended period will feature a zonal flow into Monday. The flow will
then turn SW ahead of an approaching Pacific upper low for Tuesday
through Thursday. The naefs table keeps precipitable waters high over
the region through the period...averaging around /0.75/ inches. So
any showers or thunderstorms will still have the potential to
produce heavy rainfall. Ensembles were generally in good
agreement with the pattern...especially through Monday. Based on
cape/shear values...Tuesday and Wednesday will have the best possibilities
of strong to severe storms which has been consistent with previous
model runs.

Shortwaves will move through the zonal flow over the weekend
bringing isolated to scattered showers with a slight chance of
thunderstorms. It will be warm...with temperatures climbing into
the lower 80s on sun. Precipitation chances increase on Monday as the
left-front quadrant of the jet in the base of the Pacific upper
low moves into the area. Had scattered probability of precipitation for showers and
thunderstorms across the area for Monday...and continued these
through Thursday with the approach of the Pacific low. Monday will be the
last warm day before the system brings more seasonable conditions
into the region. Arthur



Patchy fog will affect areas from kmls to kbhk this morning
producing IFR and lower conditions. Otherwise...scattered showers
will become more numerous this afternoon...especially from
Harlowton to kbil to kshr west. There will also be a chance of
afternoon thunderstorms. Some of the showers and storms may
produce heavy rainfall resulting in MVFR/IFR conditions. More
showers and thunderstorms will affect the area tonight with
associated MVFR/IFR conditions. Arthur


Preliminary point temp/pops...

Today Friday Sat sun Monday Tuesday Wednesday
bil 068 049/065 047/079 053/082 055/081 053/075 050/069
7/T 63/west 22/T 22/T 24/T 44/T 43/T
lvm 064 045/065 047/074 050/078 050/076 048/069 044/064
7/T 54/T 33/T 33/T 35/T 54/T 44/T
hdn 071 050/068 045/081 053/084 055/085 054/077 049/071
6/T 63/west 11/b 22/T 24/T 44/T 43/T
mls 074 049/067 046/078 054/081 056/084 056/076 052/070
3/T 42/west 11/b 32/T 24/T 44/T 44/T
4bq 070 050/064 045/075 054/080 056/084 057/076 052/068
4/T 44/west 11/b 22/T 24/T 45/T 53/T
bhk 071 046/064 040/069 047/077 052/082 054/074 049/067
3/T 42/west 11/north 31/north 24/T 44/T 44/T
shr 064 046/062 044/076 050/078 052/081 051/073 047/066
7/T 65/west 21/b 22/T 24/T 44/T 44/T


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