Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Billings Montana
340 am MDT sun Jul 31 2016
Short term...valid for tdy and Mon...
Prefrontal conditions today with hot temps and low humidity.
A surface trough will develop over our eastern zones with a good
deal of MUCAPE to the east. Models generally push the surface
trough east to the Dakota border this afternoon. We expect to see
strong to severe thunderstorms develop on this convergent
feature late today. We will leave the mention of severe storms in
Carter and Fallon counties for awareness...but prog trends suggest
the highest potential for a severe threat is east of the Stateline
in the Dakotas. In the meantime, increasing SW flow will tap some
monsoonal moisture to the south and push short wave energy across
our County Warning Area. We anticipate convection starting in the mountains by
mid-afternoon and pushing out onto the plains by evening. Some of
this may linger well into the night east of Billings. We do not
expect any of this activity to be very strong as MUCAPE and
helcity will be quite low.
Cold front is progged to move through Billings around 900 PM, and
the remainder of the region overnight shifting winds from westerly
to northerly for several hours. Weak return flow on Monday will
mean cooler temps and less instability with a better capped
environment. Thus, have kept pops at zero to start the work week.
Long term...valid for Tue...Wed...Thu...Fri...Sat...
Models remain consistent through the extended period. The main
impact period with the extended will be a strong frontal passage
during the Tuesday night/Wednesday morning timeframe.
Current forecast has things covered well so very little changes
were made with this issuance. An upper low and trough will be over
the Pacific northwest Tuesday resulting in a southwest flow aloft
across our forecast area. A few disturbances within the flow will
bring a slight chance for a shower or thunderstorm Tuesday
afternoon and evening. At the same time, a surface low over
Wyoming will bringing an easterly surface wind which may hold
temperatures down a few degrees from previous thinking. However,
we can't rule out some compressional warming ahead of the front so
Tuesday still looks to be the hottest day in the extended period
with temperatures well into the 90s. Winds will shift abruptly
and be gusty from the northwest then north Tuesday night/Wednesday
morning behind the front.
Gusty northwest winds will continue Wednesday but temperatures
will be about 10 to 15 degrees cooler with readings at or slightly
below normal in the middle to upper 80s. Dry conditions are
expected Thursday and Friday with seasonal temperatures Thursday.
Temperatures return back into the 90s Friday into next weekend
along with a chance for thunderstorms. Hooley
Skies will be mostly sunny with no widespread aviation hazards
expected. An isolated shower or thunderstorm and associated MVFR
condition will be possible. A strong to severe thunderstorm is
possible across the far east in the vicinity of the Dakota borders
this afternoon into this evening. Otherwise, VFR conditions will
prevail today. Hooley
Preliminary point temp/pops...
Tdy Mon Tue Wed Thu Fri Sat
bil 097 061/090 060/096 062/086 055/085 057/091 061/091
1/u 20/u 02/T 21/u 11/u 11/u 12/T
lvm 097 048/091 050/096 051/083 045/085 048/090 051/089
1/u 10/u 12/T 21/u 11/u 11/u 12/T
hdn 100 059/091 056/098 060/088 051/086 057/093 059/093
1/u 30/u 02/T 21/u 11/u 11/u 12/T
mls 099 065/091 061/098 065/087 056/084 060/093 064/092
2/west 20/u 02/T 21/u 11/u 11/u 22/T
4bq 100 064/092 061/099 066/088 055/086 059/093 063/091
2/west 20/u 02/T 21/u 11/u 12/T 22/T
bhk 098 061/089 055/094 063/086 053/082 057/089 059/087
2/T 21/u 02/T 22/T 11/u 11/u 22/T
shr 098 057/092 056/098 058/088 050/087 054/092 056/089
2/west 20/u 02/T 21/u 11/u 11/b 12/T