Area Forecast Discussion
Issued by NWS Glasgow, MT
FXUS65 KGGW 280246 AAA
Area Forecast Discussion...UPDATED
National Weather Service GLASGOW MT
846 PM MDT SAT AUG 27 2016
.SHORT TERM...for northeast Montana...tonight through Mon...
Sent an update tonight simply for minor tweaks and adjustments to
the near-term forecast grids based on the latest model consensus.
Might be a few virga showers or sprinkles over our far NW zones
Previous short term discussion: Look for nearly zonal flow aloft
tonight and Sunday. Shortwave trough currently over BC and WA this
afternoon will move across Alberta tonight and Saskatchewan on
Sunday. This will bring a dry frontal system across Eastern
Montana Sunday morning which will turn southeast winds tonight to
the northwest Sunday morning. Expect some clouds tonight and
Sunday with this system.
Surface high will build into the area Sunday Night with dry
weather. Winds will turn to the east or southeast on Monday as
the high moves to the east. Upper ridge will build north toward
Montana on Monday with mostly clear skies over the area. Forrester
.LONG TERM...Mon night through Sat...
Changes to the forecast first focused on the periods around
Monday night to Thursday where a large ridge is further
amplifying. This has raised daytime highs and overnight lows
during these periods. Conditions should also remain mostly dry
with some moisture maybe sneaking in around Wednesday night.
Periods beyond Thursday are in greater question as models are
having trouble deciding how to break down the ridge. Confidence is
low and fully anticipate the forecast to change moderately in
future iterations from this point onward. GAH
PREVIOUS LONG TERM DISCUSSION:
The large-scale synoptic flow pattern in the extended forecast
period remains dominated by a very strong ridge of high pressure
over the Rocky Mountain and High Plains regions of the country.
Further upstream a trough of low pressure repeatedly, but slowly
tries to break down this high pressure ridge, but is not entirely
successful in doing so until the far end of the extended forecast
The only chances for precipitation in the Day 4 to Day 8 time
period will be fleeting and scattered at best. As the western
trough finally is able to shift into the northern Rockies, some
more organized and widespread precipitation becomes possible, but
that looks to happen more toward the end of next weekend.
Expect daily hot temperatures throughout the period with a cool
front arriving by next Saturday or Sunday. BMickelson
Flight Category: VFR
Synopsis: A stable atmosphere with scattered-broken mid-level
clouds will prevail across the TAF sites throughout the cycle.
Winds: South less than 10 kts overnight, then veering to the
northwest and increasing to 10 to 15 kts Sunday behind a cold