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Area forecast discussion...updated 
National Weather Service Billings Montana
912 PM MDT Tuesday Jun 2 2015

active evening with thunderstorms as a couple of batches of
storms rolled through the area. The first batch ran across Big
Horn County into parts of southeast Montana. These were the
strongest storms of the night with deep cores that likely produced
hail. Did not get severe hail reports in those storms..but radar
indicated hail size in those storms were around quarter size. The
second batch of storms developed west of Billings and tracked
through town shortly after 8 PM. These storms produced heavy rain
rates of a half inch in 15 minutes...along with pea to dime size
hail. The second batch of storms was rolling across south central
Montana now with heavy rain and small hail. A third batch of
showers were moving off the mountains headed back into south
central Montana. Adjusted probability of precipitation for radar trends. Pulled low probability of precipitation
back west and south to cover more areas overnight as models show
shortwave energy streaming in through the night on southwest flow
aloft. Twh


Short term...valid for Wednesday and Thursday...

The environment this afternoon and evening will be favorable for
the potential for strong thunderstorm activity.

Convection has already started in the far western zones...with
some reports of small hail near Columbus.

Temperatures across the region have been lower than yesterday...due to
the more stable environment after last evenings widespread
precipitation. A few mesoscale boundaries have formed from the
earlier mesoscale convective system in northeastern Montana...and the convection has fired
along those.

For the rest of this afternoon and evening...expecting a similar
setup as last evening...but with higher potential energy and
a little better shear. In looking at the analyses...the best
chance for severe storms appears to be in southern Big Horn and
Sheridan County Wyoming. Storm Prediction Center sseo forecasts have kept the main
band of convection confined from Billings eastward through the
early evening hours.

Expect storms to move fairly quickly as the middle levels appear to
be somewhat dry. This will favor forward moving storms with
stronger winds behind them. Like last evening...the main threats
will be hail...strong winds...frequent lightning...and heavy
downpours. Singer

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

Inter and intra model consistency continues in the extended. The
period will be dominated by a trough along the West Coast. This
will continue the pattern of southwesterly flow aloft with waves
of energy moving through the flow across southern Montana.

Afternoon showers and thunderstorms will be common through the
long term. The southwesterly flow will be supply some good
Pacific moisture to the region. Precipitable water values will
still be in the 0.75 to 1 inch range. Some instability will be
present...though through the weekend values will be a bit lower.

The temperatures will generally be warming going into the
weekend. As temperatures climb towards 80 degrees. Reimer



Scattered thunderstorms will continue this evening...tapering off
after midnight. Local MVFR/IFR conditions in heavy rain can be
expected near storms. Stratus will persist over northeast
locations including the kmls taf site...slowly lowering to LIFR
levels by sunrise. Before sunrise may see areas of fog and stratus
develop just about anywhere rain has fallen. This may include all
taf locations with flight categories LIFR or briefly lower. Any
fog or stratus will dissipate by middle to late morning Wednesday.

Preliminary point temp/pops...

Wednesday Thursday Friday Sat sun Monday Tuesday
bil 049/069 051/071 052/073 055/075 053/079 055/081 056/079
42/T 44/T 34/T 54/T 32/T 22/T 23/T
lvm 045/067 047/070 049/070 049/073 050/075 052/077 051/076
43/T 43/T 34/T 54/T 33/T 33/T 34/T
hdn 047/073 052/074 052/077 055/077 054/081 055/083 056/081
52/T 35/T 34/T 54/T 32/T 22/T 23/T
mls 048/072 054/069 052/075 057/076 054/080 056/082 058/080
21/b 45/T 33/T 55/T 41/b 12/T 23/T
4bq 048/072 054/071 053/075 056/075 054/078 055/080 056/079
42/T 46/T 33/T 65/T 52/T 23/T 34/T
bhk 047/069 048/068 051/074 053/074 051/078 052/080 053/077
31/b 36/T 32/T 55/T 51/b 12/T 24/T
shr 046/069 049/071 049/073 052/072 050/075 051/077 052/077
33/T 55/T 44/T 54/T 42/T 33/T 34/T


Byz watches/warnings/advisories...



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