Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Billings Montana
400 am MDT sun Aug 30 2015

Short term...valid for today and Monday...

An upper low and trough currently moving across the Pacific
northwest will move across our forecast area today and tonight.
Areas of vorticity have already moved into the western half of the
state this morning and this has been producing scattered showers
and isolated thunderstorms across western Montana southward into
western Wyoming. Some of this activity has made it into our
central and western zones but the bulk of the activity has been
over the mountains. As the system moves east today it will bring a
continued chance for showers and thunderstorms across our forecast
area with the highest chances along and west of a Roundup-
Billings- Sheridan line.

The main weather impact for the short term period with be a
strong Pacific front that will sweep across our western counties
late this afternoon into this evening and our far eastern counties
late tonight. Southwest winds will gust in the 30 to 40 miles per hour range
ahead of the front across our central and western areas. Winds
will shift to the west and northwest behind the front and continue
to be quite gusty at times this evening and overnight.
Temperatures today will be slightly cooler than yesterday but
still very warm with 80s to lower 90s common. Although humidities
will be higher...the combination of dry conditions...very warm
temperatures and a strong front will result in dangerous fire
conditions this afternoon into early this evening.

A dry zonal flow aloft will prevail for Monday. Temperatures will
cool to more normal levels for this time of year with upper 70s to
lower 80s common. Hooley

Long term...valid for Tuesday...Wed...Thu...Fri...Sat...

Overall extended period is progressive as the strongest jet
energy around the Pacific northwest trough reaches the base of the
trough Tuesday night and the last of the impulses maintaining the
strong flow aloft exits the area later on Saturday. There is a
subtle pattern change Wednesday into Thursday where models
indicate a bit better infusion of subtropical moisture into the
southwest flow aloft which increases the chance of shower and
thunderstorm activity by Thursday.The ejecting Pacific northwest
trough axis weakens over the weekend but gives a chance for
unsettled weather before drying begins to kick in on Sunday.

Temperatures cool late in the week as the the approach of the
trough bringing lowering heights and pushing the surface trough
into the Dakotas. Friday and Saturday could be near 70 with some
locations remaining in the 60s. Borsum


Windy conditions and isolated showers and thunderstorms can be
expected west of kbil today with quieter conditions to the east.
Klvm may see wind gusts off and on in excess of 40kts through the
day. By late afternoon a cold front will begin moving from west to
east across the area. Expect isolated thunderstorms and wind gusts
to 30 kts to be possible with the front this evening as it
spreads into southeast Montana. Borsum

Preliminary point temp/pops...

Today Monday Tuesday Wednesday Thursday Friday Sat
bil 086 054/082 055/088 059/088 055/074 048/069 047/070
3/T 20/u 00/u 11/u 11/b 23/T 33/T
lvm 087 046/081 046/085 050/084 046/072 041/066 038/069
3/T 20/k 00/k 11/b 23/T 44/T 43/T
hdn 091 052/082 053/091 057/092 054/078 048/073 048/072
2/T 20/u 01/u 11/u 11/b 22/T 33/T
mls 090 057/082 054/091 060/094 058/081 051/074 049/073
2/T 30/u 00/u 11/u 11/b 22/T 22/T
4bq 094 056/080 055/091 059/094 058/082 053/076 051/071
2/T 30/u 00/u 11/u 11/u 13/T 33/T
bhk 093 053/079 052/090 057/094 057/084 051/076 049/073
2/T 30/u 01/u 10/u 11/u 12/T 33/T
shr 091 050/083 047/090 054/091 051/081 046/073 044/070
2/T 20/u 00/u 11/u 11/b 12/T 33/T


Byz watches/warnings/advisories... flag warning in effect until midnight MDT tonight for
zones 28-29-34-35-39>42-56-63>68.



National Weather Service Glossary of Abbreviations