Area Forecast Discussion
Issued by NWS Glasgow, MT
FXUS65 KGGW 250347
Area Forecast Discussion
National Weather Service GLASGOW MT
847 PM MST Fri Feb 24 2017
.SHORT TERM...for northeast Montana...tonight through Sun...
An area of snow showers continues to push through Northeast
Montana this evening. Expect only a light coating on roadway
surfaces through the overnight hours. Otherwise limited updates
made to the current forecast. Proton
PREVIOUS SHORT TERM DISCUSSION:
This period will be controlled by an upper trough over the area
with disturbances dropping into the area.
Abundant moisture under the trough will continue to contribute to
light snow showers or flurries through Saturday. The strongest
disturbance moves through Saturday afternoon across the northeast
zones bringing up to an inch of snow.
A break in the action occurs Saturday Night but cloudy conditions
should keep temperatures from bottoming out.
A weak surface low that moves through Saturday Night weakens
and departs Sunday. Colder air will follow in its wake with more
flurries/light snow showers.
Temperatures will remain below normal through the weekend. TFJ
.LONG TERM...Sun night through Fri...
There will be a continuation of the the broad upper trough over
much of North America bringing cool and snow-showery conditions
through the extended period. Sunday night begins with a split
trough arrangement with the northern segment over the prairie
provinces and the southern wave digging through the Pac-NW. A
secondary southern wave could bring an increased chance for snow
Monday night and Tuesday morning. However there is not much model
agreement concerning the precipitation. By Wednesday, a high
pressure ridge off to the west will establish a steady northwest
flow aloft for Northeast Montana with embedded moisture and
vorticity, enough to possibly kick off more precipitation, maybe
mixed, before a high pressure ridge quiets conditions and bring
about some warming. A peek out further into the weekend suggests
the possibility of a clipper. Few significant grid edits,
otherwise just refreshed the grids to the latest guidance.
PREVIOUS LONG TERM DISCUSSION:
Upper trof over North America with northwest flow into Montana
will influence the weather pattern through most of next week.
Several shortwaves are expected to drop across the region
producing occasional light snow but no major event is anticipated.
Overall temperatures will return to near normal values for late
February for most of the period. Ebert
FLIGHT CAT: IFR-VFR
SYNOPSIS: A frontal boundary is pushing south through Northeast
Montana this evening. Radar echos are showing snow showers across
the area, with additional echos far upstream over southern
Alberta/Saskatchewan. GOES imagery is showing is showing a
strato-cumulus deck across northeast Montana with a feeder band
upstream in southern Alberta/Saskatchewan. Surface observations is
showing these showers to drop in and out of IFR across both KOLF
and KGGW. These showers should be pointed downstream at KSDY and
KGDV over the next few hours.
WIND: light and variable through midnight, switching to the
northwest at 5 to 10kt Saturday Morning, then veering west at 10
to 15 kts during the afternoon.
Ice jams and high water levels continue on the Yellowstone River
with continued fluctuating river levels.
In Dawson County, an ice jam raised levels overnight near
In Richland County, a reported jam from the DES was located
between Fairview and Sidney near the Richland Park.
With little change in runoff and melting of the ice jams expected
over the next several days, the Flood Watch was extended through
Later next week, things could change a bit as warmer air could
melt or move ice jams along.
Elsewhere, some county controlled low water crossings in
Roosevelt County were reported this week. These will probably slow
by this weekend with the colder air.
Flood Watch through Monday afternoon for Dawson...Richland.