Area Forecast Discussion
Issued by NWS Glasgow, MT
FXUS65 KGGW 270240
Area Forecast Discussion
National Weather Service GLASGOW MT
840 PM MDT TUE JUL 26 2016
.SHORT TERM...for northeast Montana...tonight through Thu...
Added small hail, gusty wind and heavy rain to the ongoing
forecast based on the history of the line of storms moving into
the region. No other updates made to the forecast at this time.
Previous Discussion...Unsettled conditions expected to continue
through this period. Convection firing up over the
northern/canadian rockies this afternoon is next item being
watched this afternoon. This area is expected to drift east into
the cwa later tonight. Severe thunderstorms are not expected and
most of the strong storms should stay over central Montana.
The next couple of days will be unsettled as low pressure to our
south will lock in the humidity with an easterly upslope flow into
the higher terrain to our west. Upper disturbances and/or daytime
convection off the higher terrain should help in generating
showers/thunderstorms each day. Any strong thunderstorms should
mainly stay west and south of the CWA.
Daytime temperatures as a result will be about 5 to 10 degrees
below normal. TFJ
.LONG TERM...Thu night through Tue...
The going forecast as described below stands, no noteworthy changes
were made. Considerable model differences exist for next weeks
trough...thus confidence in the overall forecast for this time is
Previous long term discussion...The extended period begins
Thursday evening with northwest flow aloft over Northeast Montana.
This flow pattern is based on the area of persistent high pressure
and hot desert air over the Southwest and the large eastern Canada
trough anchored by the Hudson Bay low. This places the local area
near the boundary between the two air masses. Thus, the frequent
weak short-waves and embedded disturbance will find enough
instability to kick off isolated to scattered thunderstorms.
Conditions begin to change for the weekend when the ridge moves
east over eastern Montana. This push is caused by a deepening
trough off the Pac-NW and BC coast. Thickness heights ramp up and
upper flow backs around to the southwest. Weekend temperatures
become hot again.
By the end of the weekend the Pac-NW trough sends a cold front
across the Divide. This will lead to more chances for storms and
possibly cooler temperatures by mid-week.
VFR conditions will prevail. However, scattered showers and
thunderstorms at times will be accompanied by MVFR to IFR vsbys
and mid level ceilings. Some storms may produce gusty and erratic
winds and small hail. Prevailing winds will be from the east at 5
to 15 kts. Maliawco