Area Forecast Discussion
Issued by NWS Glasgow, MT

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FXUS65 KGGW 240304 AAA

Area Forecast Discussion...UPDATED
National Weather Service GLASGOW MT
904 PM MDT SAT JUL 23 2016

.SHORT TERM...for northeast Montana...tonight through Mon...

The Surface Frontal Analysis places the stationary front well to
our east and south, with the clipper-like short-wave trough
heading into Manitoba. The result is continued cool air advection
that places Northeast Montana within the cool air-mass boundary
tonight. Lows will be cooler tonight than last night by several
degrees. There are still a few stray boundaries that are kicking
off convcection in Canada and southern Montana. So will not
eliminate slight chance pops. Early evening winds are expected to
drop below 20 mph across Fort Peck Lake around sunset. So will let
the wind advisory expire then.


Previous Discussion:
Synoptic Setup: A large high pressure heat dome lies over the
southwestern quadrant of the CONUS while zonal flow runs through
the Pacific Northwest, Montana, and southwest Canada. A closed
low currently resides in the flow over southern Saskatchewan.

Today through Tonight: The closed low to the north is currently
moving off to the east and allowing some wrap around
precipitation to drop south. Models and satellite trends do not
appear to be allowing this to cross the border at this time and
this trend should remain intact. A pressure gradient has also
formed behind the low and when combined with the daytime mixing
has allowed for wind gusts that are a little bit higher than
predicted. These gusts should dissipated near sundown as the
mixing layer stabilizes. A weak shortwave may tag along the
northern zones tonight but moisture looks too minimal to have
more than slight chance PoPs.

Sunday through Monday: Zonal flow will gain a northwest component
as the heat dome to the southwest expands north and forms a ridge
to the west. This should stabilize the atmosphere and drop PoPs
and QPF down to near zero. This will also place northeast Montana
under a warming trend with progressively higher surface
temperatures for the next couple days. GAH

.LONG TERM...Mon night through Sat...

Update: The forecast as described below stands, with no
significant changes made. Gilchrist

Previous long term discussion: Quasi-zonal flow aloft is expected
Monday Night and Tuesday. Monday Night and Tuesday morning looks
mainly dry with a shortwave ridge. Will see warm summerlike
temperatures over the region. A shortwave trough Tuesday Night
with unstable air mass could produce thunderstorms over the
forecast area starting Tuesday afternoon and continuing through

Another wave on NW flow aloft Wednesday Night and Thursday will
bring more chances for showers and thunderstorms with somewhat
cooler temperatures.

The chance for showers and thunderstorms could linger into Friday
as models differ on how quickly to move the wave to the east.
Then, an upper ridge builds into the area with mainly dry weather
for Saturday. Forrester


Flight category: VFR.

High pressure will continue over the region for the next 24 hours.
This will allow for mainly clear skies and light wind under 15
knots.    Proton




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