Area Forecast Discussion
Issued by NWS Billings, MT

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FXUS65 KBYZ 261538

Area Forecast Discussion...Updated
National Weather Service Billings MT
938 AM MDT Fri May 26 2017


Overall the forecast is on track. Did adjust PoPs and QPF mainly
in the Bighorns, but only made some minor tweaks. Latest hi-res
CAMs continue to show some isolated to scattered activity this
afternoon west of Billings, mainly over the higher terrain.


.SHORT TERM...valid for Tdy and Sat...

An upper low over south central Canada combined with a high
pressure ridge axis over the Pacific Northwest will provide for a
continued northerly flow aloft across our forecast area today. The
low will provide another day of unsettled cyclonic flow across
the area and this combined with somewhat steep lapse rates across
our central and western areas will result in a chance for showers
and isolated thunderstorms today into this evening along and west
of a Roundup- Billings- Sheridan line. Winds today will be much
lighter than yesterday except from about Rosebud County eastward
where gusty northwest winds will continue. 850mb temperatures will
be a few degrees warmer today allowing readings to inch closer to

Cyclonic flow aloft will continue one more day Saturday as the
above mentioned upper low slowly shifts east. A weak disturbance
aloft will move overhead bringing another chance for showers and
isolated thunderstorms. At the same time, the ridge over the
Pacific northwest shifts a bit further east as well allowing for
rising heights across south central Montana. As a result, expect
temperatures to warm to or slightly above normal with readings in
the upper 60s to lower 70s. Hooley

.LONG TERM...valid for Sun...Mon...Tue...Wed...Thu...

Models were in decent agreement on the pattern for this upcoming
week. The pattern will be slow moving as an omega block will be in
place over most of North America. The northern Rockies will be
under the influence of higher pressure with gradually building
heights. The flow aloft through the early part of the period will
be northwest and consensus was for the models to bring weak energy
through the state and trigger afternoon and evening showers and
thunderstorms. The ridge is progged to slide east by the end of
the week and this could open the door up for increasing chance of
thundestorms. Temperatures will warm through the weak with high
pressure aloft. TWH



VFR conditions are expected today. An area of low pressure over
Idaho will slide into western Wyoming today and spread clouds and
a chance of showers to western locations, mainly the mountains and
foothills. An isolated thunderstorm or two cannot be ruled out.
Local MVFR conditions are possible in the heavier showers.
Mountains will become obscured. TWH/STP



    Tdy Sat     Sun     Mon     Tue     Wed     Thu
BIL 066 045/072 049/075 050/075 049/079 052/082 053/082
    1/B 12/T    13/T    22/T    11/U    11/U    12/T
LVM 062 036/070 041/074 042/074 044/077 045/079 045/080
    3/T 22/T    23/T    22/T    22/T    11/B    12/T
HDN 067 043/072 046/076 046/076 047/081 050/085 051/083
    1/B 12/T    12/T    22/T    01/U    01/U    12/T
MLS 069 044/073 048/076 046/074 046/079 051/082 052/083
    0/B 12/T    12/T    00/U    00/U    00/U    12/T
4BQ 066 043/070 046/074 044/073 044/077 048/081 050/081
    0/B 12/T    12/T    10/U    00/U    00/U    12/T
BHK 065 041/069 043/071 041/069 038/074 046/076 047/077
    0/B 02/T    12/T    00/U    00/U    00/U    01/U
SHR 059 039/066 043/071 042/072 042/076 045/080 047/080
    3/T 32/T    23/T    22/T    11/B    11/B    12/T




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