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fxus65 kggw 292026 
afdggw

Area forecast discussion
National Weather Service Glasgow Montana
226 PM MDT sun Mar 29 2020

Discussion...

Afternoon discussion:
updates to the forecast this afternoon appeared to be mostly
focused on pops from Monday night to Tuesday. Most of the periods
have dried out except for Tuesday where Post front showers pop-
up. The latest ensemble also attempted to drop winds on Tuesday
afternoon, but with the flip flopping decided to restore gusty
winds from the previous forecast to hold more steady with changes.
Snow will be minimal with this passage and very little may occur
Tuesday night leading to probably no snow pack.

In addition Wednesday through Friday are now raising confidence to
normal as the ensembles are getting the idea that the snowpack
will not be in place. They have raised temperatures from the
previous forecast slightly and 500 mb height Standard deviations
over these periods have narrowed substantially compared to 24
hours ago. However, much colder temperatures compared to now are
in still in store. So expect a mostly cloudy, cold change coming
up! Gah

Morning update:
changes this morning were minor and consisted of updating the
next couple hours to match current observations. Otherwise, the
forecast is in great shape. Gah

Morning discussion:
an upper level ridge that brought sunny skies and warm
temperatures over the region continues through today and Monday.
Many areas can expect to be a few degrees warmer than yesterday
with some locations reaching into the lower 60s. Some snow cover
in the north central zones melted a bit yesterday and as a result,
the river gauges have responded to melt. Close monitoring of the
associated steams will be necessary with further melting expected
over the next couple days. Additional precipitation following the
melt may contribute to water rises.

The ridge will transition to southwesterly flow before a low
pressure system from the western US pushes east through Montana
Monday night. Highs on Monday will again reach into the lower 60s,
however, clouds will increase from the west as the trough
approaches. There is a possibility of isolated thunderstorms on
Monday afternoon and evening ahead of the frontal passage but will
need to watch as new model runs arrive. A chance of light rain from
west to east on Monday evening. Temperatures turn colder Tuesday
with ensemble and deterministic models coming into agreement on
the downward trend and timing. Model agreement quickly diverges
after Tuesday. Subsequent deterministic runs of NAM and GFS seem
to nudge temperatures up a couple degrees from a total plummet,
but is continuing to signal that unseasonably cold temperatures as
strong cold air advects behind the front and any precipitation
transitions from rain into snow midweek. Snow accumulation is
expected to minor to none. Also expecting gusty northwest winds
midweek.

Cold air may sit over NE Montana through the rest of the week. It
may begin to gradually mix out Friday with zonal flow and
temperatures may potentially come up over the weekend. However,
given the model uncertainty, this too will have to be revisited
as agreement over the midweek system develops.

Rux



&&

Aviation...

Flight cat: VFR

Discussion: a ridge of high pressure will keep the weather warm
and dry. High clouds and afternoon cumulus are possible through
Monday.

Wind: southwest to south at 10 to 15 kts this afternoon. Backing
to the south to southeast and deacreasing to around 10 kts or less
this overnight.

Gah



&&

Glasgow watches/warnings/advisories...none.

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