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Area forecast discussion 
National Weather Service Billings Montana
241 am MDT Sat Aug 23 2014

Short term...valid for today and sun...

Very dynamic trough of low pressure is currently over Montana and
is bringing areas of heavy rain to the forecast area. Infrared satellite
showing baroclinic Leaf structure over our far eastern zones this
morning as well as cooling cloud tops. Low level jet has set up
and is advecting significant moisture into the area. Preciptable
water values have risen to an inch at Billings and 1.4 inches over
our eastern zones during the night. Very strong forcing aloft as
upper trough is bringing strong diffluence aloft with additional
lift from a jet maximum. Upper trough will move slowly across the
region today with it being negative titled. Main concern is
potential for flooding of small streams over the southeast today.
Flood Watch was issued last evening for are four eastern counties
and will keep this going for today. Radar estimates of rainfall
overnight in our east is 1 to 2 inches. An additional 2 to 3
inches will be possible there before this system finally winds
down.

Have raised probability of precipitation over the western and central zones this morning
with precipitation being pushed to the northwest. Soundings indicate down
slope winds to develop from Billings westward this afternoon but
will continue to keep likely probability of precipitation going for these areas given the
strong lift over the area and soundings remaining nearly saturated
from the surface to 400 mb as well as a deep Omega field. 700 mb
temperatures are still prognosticated to lower to a -2c tonight and
Sunday morning which will result in several inches of snow for
mountain areas above 10000 feet.

Upper trough and closed upper low associated with it will
continue lifting to the northeast tonight and precipitation will slowly
diminish over our western and southern zones. The northern zones
will continue to see wrap around precipitation from the upper low
and have kept likely probability of precipitation there through Sunday morning. By Sunday
night...strong down slope winds will develop as the system
continues to move away from the area and only a slight chance of
showers are expected along our norther zones with the rest of the
region becoming dry. High temperatures will continue to run 15 to
20 degrees below normal today and Sunday. Richmond

Long term...valid for Monday...Tue...Wed...Thu...Fri...

Models are in better agreement through the extended period than
what was the case this time last night. A second upper low moves
out of the Pacific northwest and into the Great Basin area on
Monday into Tuesday keeping the northern rockies in general
troughiness. This will bring continued chances for showers and
thunderstorms to the entire forecast area through Tuesday.
Temperatures will remain well below normal Monday and Tuesday with
readings only in the 60s to lower 70s. Models then shift the upper
low east with ridging building in from the west on Wednesday
continuing into Friday. This will allow for dry conditions along
with much warmer temperatures with readings returning to normal by
the end of next week. Models then diverge a bit by next weekend in
bringing another upper low and trough across the northern
rockies...but differences continue to exist in strength and
timing. Hooley
&&

Aviation...

Areas of rain and isolated thunderstorms will continue into this
evening as a strong upper low moves across the area. The rain will
be heavy at times. Expect many areas to have MVFR to IFR and
occasional LIFR conditions. Areas of fog will be likely as well
through this morning. The mountains will be obscured throughout
the day. Hooley



&&

Preliminary point temp/pops...

Today sun Monday Tuesday Wednesday Thursday Friday
-------------------------------------------------------
bil 061 048/064 047/069 050/072 053/082 057/087 061/085
9/T 44/T 23/T 32/T 11/u 01/u 11/u
lvm 059 045/064 042/068 044/072 048/083 051/086 051/084
8/T 53/T 23/T 42/T 11/u 00/u 01/u
hdn 067 049/065 046/072 050/074 051/083 055/088 059/088
9/T 55/T 13/T 32/T 11/u 01/u 11/u
mls 067 051/061 047/069 051/071 053/082 057/087 062/090
+/T 86/T 22/T 22/T 11/u 11/u 11/u
4bq 070 050/063 045/069 052/070 051/081 056/087 060/089
9/T 63/T 22/T 33/T 11/b 11/u 11/b
bhk 065 050/060 045/067 047/068 048/078 053/083 059/086
+/T 86/T 22/T 34/T 21/u 11/u 11/u
shr 068 047/064 044/071 048/071 048/081 051/087 055/089
6/T 53/T 13/T 44/T 11/u 00/u 01/u

&&

Byz watches/warnings/advisories...
Montana...Flood Watch in effect through this afternoon for zones
32-33-36-37.
Wyoming...none.

&&

$$
Weather.Gov/Billings

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