Area Forecast Discussion
Issued by NWS Billings, MT

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FXUS65 KBYZ 221905

Area Forecast Discussion...Updated
National Weather Service Billings MT
105 PM MDT SUN MAY 22 2016

Updated forecast to add possible gusty winds/small hail to areas
east of KBIL this afternoon. 0-6km Bulk Shear combined with very
steep lapse rates may produce some stronger thunderstorms. Also
increased wind speeds in several areas based on observations.
Mixing was quite efficient this afternoon and also resulted in
higher than expected temperatures so have raised those as well.


.SHORT TERM...valid for Tdy and Mon...

Vigorous weather system that moved through the region yesterday
will generally be situated east of us today. In its wake is a
cooler and somewhat drier air mass. However, we remain under a
broad cyclonic flow aloft with a large pool of cooler air at
500mb. This will create an unstable atmosphere as we warm up with
moderate lapse rates the result. There are still some weak
pockets of energy revolving through the flow so this combined
with relatively steep lapse rates should produce a few showers
and thunderstorms across the CWA. Models suggest most of this will
initiate off the mountains in the afternoon, but a pocket of
convection is also hinted at in the southeast corner due to some
vorticity rotating through the southern branch of the broadscale

The afternoons convection should generally die off with the
setting sun, but expect another round of the same for Monday as we
remain under the influence of the upper low to our north. BT

.LONG TERM...valid for Tue...Wed...Thu...Fri...Sat...

Models agree on the overall pattern of upper troughiness and lack
of strong ridging through next weekend. This pattern is favorable
for numerous disturbances/shortwaves to move across the region,
triggering isolated to scattered showers and thunderstorms each
day. No organized, synoptic-scale precipitation systems look to
affect the region until perhaps next Saturday, when the 00z ECMWF
brings a vigorous upper low close to the western and central CWA.

Temperatures should be near seasonal normals throughout the
period.  RMS/BT


Scattered showers and thunderstorms could redevelop especially
over southeastern MT and near/south of KLVM after about 17z.
Mountains will be obscured at times in showers and thunderstorms.
Southwest winds will be gusty near KLVM through the day at 20 to
40kts. Otherwise...VFR will prevail today and tonight. Chambers



    Tdy Mon     Tue     Wed     Thu     Fri     Sat
BIL 068 044/067 044/066 045/069 047/069 048/070 049/071
    2/T 13/T    23/T    33/T    32/T    34/T    43/T
LVM 064 039/060 038/060 040/065 040/065 041/065 041/067
    3/T 24/T    24/T    43/T    35/T    54/T    43/T
HDN 073 042/071 042/069 047/071 048/071 049/072 049/074
    2/T 12/T    22/T    33/T    33/T    33/T    33/T
MLS 073 046/072 047/071 050/072 050/073 050/072 051/075
    2/T 12/T    12/T    33/T    33/T    23/T    32/T
4BQ 071 042/071 042/070 047/070 046/070 048/070 048/073
    3/T 12/T    12/T    43/T    33/T    33/T    32/T
BHK 074 042/071 042/070 048/069 047/070 047/069 048/072
    4/T 22/T    12/T    44/T    43/T    33/T    32/T
SHR 074 039/067 039/065 043/065 042/066 044/066 045/069
    2/T 11/B    13/T    33/T    33/T    33/T    33/T




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