Area Forecast Discussion
Issued by NWS Glasgow, MT
FXUS65 KGGW 300306 AAA
Area Forecast Discussion...UPDATED
National Weather Service GLASGOW MT
906 PM MDT WED JUN 29 2016
.SHORT TERM...for northeast Montana...tonight through Fri...
Sent an update tonight to give more detail to and fine tune the
near and short term forecast grids for tonight and tomorrow,
following mostly the best model consensus. Current thunderstorm
just north of our international border is not well represented in
most models, but is beginning to be noticed by the HRRR. Felt it
was prudent to increase PoPs over our northern and northeastern
zones and gradually allow it to dissipate as it moves slowly
Previous short term discussion: An upper ridge over the Pacific
Northwest is translating east and is helping to drive northwest
flow aloft across Northeast Montana. Meanwhile, an embedded
shortwave is providing forcing for ascent allowing a few showers
and thunderstorms to develop over the area this afternoon into
As the shortwave ridge pushes over the region, drier weather is
expected later tonight and on Thursday. However, as a relatively
progressive pattern continues, the next shortwave will be
approaching for Thursday night and Friday with additional chances
for showers and thunderstorms. Maliawco
.LONG TERM...Fri night through Wed...
Only minor changes for the going forecast. Occasional chances of
thunderstorms during period with the main focus on a cold front
passage Saturday night. Ebert
Previous long term discussion...The general evolution of the
weather pattern for the extended forecast period will feature
increasing zonal flow and southwesterly flow aloft as a slow-
moving low pressure system over the Canadian Rockies gradually
dips southward and repeatedly introduces isolated to scattered
chances for rain showers and thunderstorms across portions of
The best consensus for accumulating precipitation seems to cluster
across our eastern zones from Saturday evening through Sunday.
Given that this time frame falls within the popular 4th of July
holiday weekend, those with outdoor and recreation plans should
closely follow the evolving threat for thunderstorms. Although for
Monday evening itself, the 4th of July, model consensus calls for
a mainly quiet night for fireworks and other planned outdoor
festivities. This time will continue to be monitored for any
changes in this expected pattern.
Wednesday and beyond, the Canadian Rockies trough will take a more
pronounced and compact dip through our northern Rockies region and
increase chances for more widespread showers and thunderstorms.
Tried to reflect this trend but it is out toward the end of the
extended forecast period. Confidence here is average at best.
SYNOPSIS: VFR conditions will prevail, though an isolated shower or
thunderstorm cannot be ruled out through this evening.
Wind: Northeast to east at 5 to 10 kts tonight... veering to the
southeast Thursday and increasing to 10 to 20 kts.