Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Glasgow Montana
319 am MDT Monday Sep 1 2014
Short term...for northeast Montana...today through Wednesday...
The day begins with a broad...long-wave trough across Continental U.S. That
has brought cooler than normal temperatures and isolated to
scattered showers to northeast Montana during the weekend. Weak
embedded disturbances and cooling aloft will maintain the weak
instability to generate isolated to scattered showers and
thunderstorms today and tonight. Most showers during the period
will be brief without much in the way of quantitative precipitation forecast.
A trough in the Gulf of Alaska drops south and gains strength
early Tuesday as it moves into the pac-NW. This action will build
up a weak ridge in advance to bring a brief warming aloft and
drying to nemont for Tuesday.
On Wednesday the trough digs into the northern rockies and then
broadens across the High Plains. This shearing action extends west
as the embedded shortwave swings north into Canada. There will be
a strong cold front in advance of the shortwave that will kick off
showers and thunderstorms...but models suggest...mostly in Canada.
Much cooler air moves in behind the cold front. Thus temperatures
will remain below normal throughout the short term period.
Long term...Wednesday night through Monday...
elongated positive tilted trough extends from Hudson Bay to
California midweek with a strong shortwave along the Canadian
border. As this shortwave zips east...the southern portion of the
trough cuts off and lingers near the California coast into the
weekend. Well developed low develops below the shortwave but for
now the models keep the heaviest precipitation generally north of
the border as the storm system tracks east on Thursday.
Behind the shortwave...with the split flow around the California
low...models deflect most of the moisture across the southern
states or well north in Canada. This will result in mostly dry
conditions for Montana with west to northwesterly flow...and
warming temperatures into next weekend. Ebert
VFR. Occasional showers or thunderstorms may briefly reduce
flood warnings remain in effect for the lower milk river in Valley
County and Beaver Creek in eastern Phillips.
On Beaver Creek...the water level at the gauge near Saco remains
above the 11 feet flood stage...but continues to slowly fall.
On the milk river...The Levels at Tampico and Glasgow continue to
show a slow fall. Water levels at Tampico should drop below flood
stage this afternoon...but not fall below flood stage at Glasgow
until late in the week.