Area Forecast Discussion
Issued by NWS Glasgow, MT
FXUS65 KGGW 251543
Area Forecast Discussion
National Weather Service GLASGOW MT
943 AM MDT WED MAY 25 2016
.SHORT TERM...for northeast Montana...today through Fri...
Update: Updated this morning to begin tapering off pops across
Prairie, Dawson, and Wibaux counties as the precipitation shield
rotates northward into far northeast Montana. Also spread pops
this morning further west into Phillips county as a few showers
are rotating in thanks to the upper low over southwest
Previous discussion: upper low will remain over SW Saskatchewan
today as a shortwave trough with a weak surface low on the east
side of the low moves north along the MT/Dakota border. This wave
will bring widespread rain showers to the eastern part of the
forecast area today. To the west, somewhat unstable air mass will
allow for some shower and thunderstorms to develop during the day
mainly in the afternoon.
The shortwave moves to the northeast tonight. The upper low
slowly drifts east across Eastern Montana tonight and Thursday
while the shortwave trough develops into a second upper low
over Southern Manitoba. An inverted surface trough is expected to
develop along the MT/SK border late tonight which will become the
focus point for rain showers on Thursday. Once again, somewhat
unstable air mass could enhance the showers and produce a few
The upper low drifts into North Dakota Thursday Night which will
diminish the chance of showers to slight chance overnight. The
effects of this low could linger over NE Montana into Friday
Morning before the low dissipates during the day. Meanwhile, a
cold front approaches from the west in the afternoon which a
chance of showers and thunderstorms. Forrester
.LONG TERM...Fri night through Wed...
Most of the long-term forecast period will be dominated by an
unsettled, trough pattern - and consequently, the forecast calls
for a prolonged wet period of weather.
At the beginning of the forecast period, the recent meandering low
center will have finally moved eastward and dissipated, leaving a
brief period of very short-wave ridging between disturbances
Friday night through Saturday morning, especially for our eastern
Saturday morning through Sunday morning, a strong Canadian Rockies
trough will sweep southward and push an average amount of rain
showers and a few thunderstorms through our CWA.
Sunday through early Monday, the flow aloft becomes nearly zonal
for another brief period of quiet weather for the central portion
of our CWA.
Monday morning through Wednesday morning, the most active period
of the forecast shows a more pronounced trough digging through the
northern Rockies and the northern high plains. Some strong showers
and thunderstorms will be possible.
In all cases, tried to blend the PoPs and Wx grids toward the
latest model consensus data. BMickelson
A widespread area of rain showers will move from south to north
through the region. Most of the organized activity will remain
east of KGGW with MVFR to IFR conditions possible - especially for
KSDY and KGDV today. BMickelson