Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion...updated 
National Weather Service Billings Montana
835 PM MDT Monday Mar 30 2015

Update...

Ridge of high pressure remains over the area tonight. This will
provide mostly clear to partly cloudy skies and light winds.
Temperatures will drop into the 30s and 40s overnight. Southwest
winds will begin to increase late tonight over western zones as
Lee side trough intensifies. Pre-frontal day in store for Tuesday
with warm temperatures and gusty winds over at least the western
half of the area. Could be a few thunderstorms in the mix tomorrow
as well...west of Billings that will add to the fire concerns for
the day. No changes to the going red flag warnings. Chambers

&&

Short term...valid for Tuesday and Wednesday...

Fire weather is again our main concern over the next couple of
days. Expect a pleasant but breezy evening ahead across our
region. Overnight lows may stay up as proggs keep some wind in the
boundary layer overnight. Broad trough moving inland on northwest
coast tonight approaches our region by tomorrow night. Ahead of it
we expect deep mixing and very warm or even near record
temperatures. Humidities should bottom out well under 20 percent
in most areas. Front sweeps through late tomorrow through the
night. Frontal passage currently expected around around 6-7 PM for
Livingston and 9-10 PM for Billings. We expect some modest cape over
area late Tuesday so some isolated showers or thunderstorms are
possible in the warm sector ahead of the front...with scattered
showers and thunder along the front...though the chance of thunder
will decrease after dark. Middle level winds do not look as strong as
last saturdays event. This appears to be a more typical ridge
crasher /though unseasonable/ and not as high impact as the high
wind we had over the weekend.

Wednesday...proggs really bottom out our dewpoints as dry air
moves in. 700-850mb winds increase Wednesday as well and along
with cold advection will make for a very uncomfortably windy day.
So despite notably cooler temperatures Wednesday...we feel with
the wind...low dewpoints and unseasonably sensitive fuels its
prudent to keep the red flag warning going through 900 PM. Bt

Long term...valid for Thursday...Fri...Sat...sun...Mon...

Cool northwest flow over the region Thursday with instability from kbil-
kshr westward under 500 mb temperatures to -32c. As weak surface ridge builds
into the northern plains we should see winds veer to a north-NE
direction...enhancing the precipitation potential in our west...especially
diurnally speaking...with some banded -shrasn possible. Wet bulb
temperatures are close to the surface so should see mixed precipitation and some
graupel with the shower activity. Highs on Thursday may not reach
50f for the first time in a couple weeks. One last weak area of pv
will exit to the east Friday but not before producing a few
showers in our east parts along instability axis. Temperatures will begin
to moderate Friday but not too quickly...should see highs in the
50s.

Broad upper ridging should bring US dry weather with temperatures creeping
back into the 60s Saturday.

Things may get more interesting next Sunday/Monday due to impacts
from fairly deep Pacific coast trough. Models are in complete
disagreement on the fate of this low with the GFS kicking energy
through Montana Sunday night and Monday...and the European model (ecmwf) keeping parent
low along the California coast with higher heights over US on
Monday. Models also not showing any run to run consistency so must
stress the uncertainty. At the very least...the combination of
light to easterly surface winds and synoptic scale ascent of some
fashion should bring an increased chance of showers Sunday/Monday.
Not sure on specifics but have raised probability of precipitation to above climatology in
our west and north for these periods...and temperatures should at least
see a slight cooling trend. It is also not out of the realm that
we could see some lower elevation snowfall at some point.

Jkl
&&

Aviation...

VFR conditions will prevail tonight and Tuesday with scattered
high clouds tonight giving way to increasing middle and high clouds
Tuesday. Well-mixed SW winds can be expected to increase tomorrow
afternoon especially west of kbil...with gusts to 35 kts along the
foothills including klvm. Jkl
&&

Preliminary point temp/pops...

Tuesday Wednesday Thursday Friday Sat sun Monday
-----------------------------------------------------------
bil 045/078 042/058 033/049 032/056 036/062 035/059 036/055
00/north 41/north 13/west 31/b 00/b 12/west 23/west
lvm 043/075 035/052 028/047 026/053 032/059 030/054 032/052
02/T 53/west 13/west 31/b 11/b 23/west 33/west
hdn 037/081 039/061 030/050 028/058 031/064 032/062 034/057
00/b 31/north 12/west 21/b 00/b 11/b 22/west
mls 039/080 041/060 031/049 028/057 030/062 034/061 035/054
00/b 21/north 02/west 12/west 00/b 11/b 22/west
4bq 037/081 039/060 029/048 025/055 028/063 033/063 034/057
00/b 21/north 02/west 12/west 00/u 00/b 22/west
bhk 036/078 038/059 028/045 024/053 027/059 032/059 032/050
00/b 21/north 02/west 12/west 00/u 00/b 22/west
shr 037/079 036/055 027/048 025/052 027/063 030/060 032/056
00/b 32/west 12/west 21/b 00/u 11/b 22/west

&&

Byz watches/warnings/advisories...
Montana...red flag warning in effect from noon Tuesday to 9 PM MDT
Wednesday for zones 28>42-56>58-63>68.
Wyoming...red flag warning in effect from noon Tuesday to 9 PM MDT
Wednesday for zones 98-99.

&&

$$
Weather.Gov/Billings

National Weather Service Glossary of Abbreviations