Area Forecast Discussion
Issued by NWS Billings, MT
FXUS65 KBYZ 280936
Area Forecast Discussion
National Weather Service Billings MT
336 AM MDT THU JUL 28 2016
.SHORT TERM...valid for Tdy and Fri...
Area of PV tracking across south central MT is currently producing
a large area of showers and thunderstorms from Big Timber to
Billings down to Sheridan. This energy will move into northeast WY
over the next several hours and would expect pcpn to do the same.
Have adjusted pops up thru the remainder of the night til 15Z this
morning to account for this activity.
Moist and unstable NW flow with more shortwave energy will bring
showers and thunderstorms across the cwa this afternoon and
evening. CAPES on the order of 500-1200 j/kg is enough for severe
storms but shear will take a notable drop from Wednesday. Current
NCAR ensemble mean is consistent with latest RAP runs in showing
greatest shear of 30-40 kts across our west and south, but only
20-25 kts across our north and northeast. Cannot discount a few
severe strong or severe storms today but our central to south
central parts may be most favored as this is also where PV will
exist late this afternoon, and NW flow may result in a boundary in
the lee of the Snowies. Will continue messaging for storm
potential today. By this evening, shortwave will pass and we will
introduce subsidence from the west. This will allow for convection
to diminish quickly after sunset, i.e. it will not be a repeat of
the current night.
Another weak shortwave will emerge from north Pacific trof and
drop thru eastern MT on Friday. Low levels will remain fairly
moist with easterly sfc winds, and although mid level temps will
begin to warm, convective temps in the upper 80s should be
achievable. Have expanded isolated pops to cover the mountains and
our central and eastern lower elevations. Any convection on Friday
will be non-severe.
Today will be the coolest day of the week with highs in the lower
to mid 80s, and perhaps only upper 70s in the east near Baker.
Warming trend begins Friday with highs back to the upper 80s or
.LONG TERM...valid for Sat...Sun...Mon...Tue...Wed...
The latest models are in good agreement through the extended
period. High pressure ridging will build over the forecast area in
response to an upper low and trough that will be situated over
southwest Canada Saturday into Sunday. This will result in rising
heights with dry conditions and temperatures well into the 90s.
As the upper low and trough move across southern Canada it will
bring a cold front across the forecast area Sunday
afternoon/evening resulting in a slight chance for a shower or
thunderstorm. Otherwise, the front will not have much impact
except to lower temperatures just a few degrees for Monday. Weak
ridging builds Monday into Tuesday before a stronger system moves
across the northern portions of the state bringing another front
across the area late in the day Tuesday or Tuesday night along
with a returned chance for showers and thunderstorms. Temperatures
will cool down to normal or just slightly below normal Wednesday
and Thursday with middle to upper 80s for most areas. Hooley
Showers and thunderstorms will be likely through 12z along and
west of a KSHR-KBIL line. Frequent lightning and heavy rain will
be the threats with these thunderstorms. Local MVFR to IFR
conditions can be expected with this activity as well. Otherwise,
VFR conditions will prevail across the forecast area this morning.
Scattered showers and thunderstorms and associated MVFR to IFR
conditions will be possible across the entire forecast area later
this afternoon and evening. Otherwise, skies will be partly to
mostly sunny with VFR conditions prevailing. The mountains will be
obscured at times throughout the day. Hooley
.PRELIMINARY POINT TEMP/POPS...
Tdy Fri Sat Sun Mon Tue Wed
BIL 083 059/089 062/096 066/095 062/090 060/092 060/087
3/T 32/T 11/U 12/T 21/B 12/T 21/U
LVM 084 050/090 053/093 057/094 051/091 052/092 051/086
3/T 21/U 12/T 22/T 21/B 12/T 21/U
HDN 084 056/090 059/097 064/097 060/092 059/095 057/089
4/T 32/T 11/U 12/T 21/B 12/T 21/U
MLS 082 059/088 062/096 067/096 064/092 062/095 062/089
4/T 32/T 11/U 12/T 21/U 12/T 21/B
4BQ 082 057/089 061/094 067/098 064/094 062/096 062/090
5/T 42/T 11/U 12/T 21/U 12/T 22/T
BHK 077 054/083 057/091 063/095 061/090 057/091 059/086
5/T 32/T 11/U 12/T 22/T 12/T 22/T
SHR 084 052/090 056/093 060/096 058/092 056/095 056/089
6/T 42/T 11/U 12/T 21/B 12/T 21/U