Area Forecast Discussion
Issued by NWS Glasgow, MT
FXUS65 KGGW 280252
Area Forecast Discussion
National Weather Service Glasgow MT
852 PM MDT Thu Apr 27 2017
.SHORT TERM...for northeast Montana...tonight through Sat...
Evening and overnight Updates...
Minor changes to Temperatures, relative humidity, chances of
precipitation, and cloud cover. Showers staying primarily over
portions of Phillips and Petroleum Counties, while the NE corner
of the state in Daniels and Sheridan counties remained mostly
clear this evening.
Main influence to the weather tonight is the persistent cutoff low
over southern Alberta and southern Saskatchewan Canada with a weak
low pressure trough running through central MT with nearly
stationary light showers along the boundary. Expecting this
feature and the showers to continue to weaken and dissipate over
the next 12 hours. A low pressure system over British Columbia
will join with the closed low and begin to push the closed low
east across Saskatchewan Canada Friday. As it pushes east the low
pressure trough and front may invigorate and produce a line of
showers and isolated thunderstorms late Friday into Saturday
morning that if they do develop are forecast to push east across
portions of NE MT. We will be watching this development. Current
precipiation estimates from this could be any where from a couple
of hundredths to around a tenth of an inch of rain in the heavier
Previous Discussion... Synoptic Setup: A large trough sets over
the Pacific Northwest running from northern Utah through southern
Idaho and Washington. A weak ridge axis runs through the western
Dakotas and far northeast Montana. At the surface an inverted
trough has set up just off the front range and is providing a
focal point for rain showers across central parts of the state.
Today through Friday: with positioning of the inverted trough to
the west and a meso ridge to the east radar echos are reaching
about the Phillips/Valley County border before dying. With no
movement of the large scale this trend is expected to continue
with clearing each day east of Glasgow and Jordan and chances for
scattered rain showers to the west. GAH
Friday Night through Saturday: A quick-moving disturbance will
make its way through northeast Montana later in the day on
Saturday and bring some chances for light rain mainly to the
western and northern areas. This remains consistent with the
overall active pattern impacting the region, with periodic
precipitation chances every day or two. Bigelbach
.LONG TERM...Sat night through Thu...
The forecast is in good shape. The narrative as it pertains to the
pattern in the long term, and therefore the grids as a reflection
of that narrative, from the morning package is still relevant and
thus no major changes to the forecast were necessary this
PREVIOUS DISCUSSION: Upper-level model weather pattern data
suggest that the extended forecast period shows a subtle shift to
a more progressive and warmer period of weather. The disturbances
that ride down the Canadian Rockies will bring off and on chances
of rain showers to the region, mainly Sunday night through Tuesday
The model consensus for precip timing and placement are rough at
best and are reflected in the forecast grids in a broad-brushed
kind of way, showing a generally less than average forecast
confidence. The scattered nature of these spring-time showers will
likely result in sporadic precipitation realized at any given
location across NE Montana. No significant storms on the horizon
for our area and gradually warming temperatures will make for a
comfortable start to the month of May.
As is usually the case, the best model consensus begins to form
around higher confidence toward the closer to current time.
VFR, with the small possibility of MVFR ceilings at KGGW.
A low pressure trough with embedded weak frontal boundaries has
created a band of light showers west of KGGW. These showers may
drift east far enough to affect KGGW tonight. Otherwise the
remaining terminal areas should remain dry.
Winds: From the east-southeast around 10kt.