Area Forecast Discussion
Issued by NWS Glasgow, MT
FXUS65 KGGW 280144
Area Forecast Discussion
National Weather Service GLASGOW MT
744 PM MDT WED JUL 27 2016
.SHORT TERM...for northeast Montana...tonight through Fri...
Isolated thunderstorms continue to dot the region this evening.
The on-going forecast had this well covered, only change was to
add hail, gusty wind and heavy rain to the southern zones based on
current activity through the midnight hour. Adjustments to current
trends were made otherwise forecast is in good shape. Proton
WNW flow aloft today will continue the next few days. A slow
moving shortwave trough will move across waves over Northeast
Montana tonight and Thursday. With an atmosphere that will stay
moist and unstable, look for showers and thunderstorms will occur
at times over the area. With CAPE as high as 1500 j/kg and lifted
index as low as -4, a few severe storms may occur tonight. Cool
air mass associated with a high pressure system to the northeast
in Manitoba will keep temperatures below normal for highs on
The shortwave will move to the southeast Thursday Night
diminishing the chances for showers and thunderstorms. A shortwave
ridge in the NW flow aloft will allow for mainly dry weather late
A shortwave trough will move across Saskatchewan on Friday.
Precipitation will stay mainly to the north of the forecast area.
A shower or thunderstorm could affect the northern zones in the
afternoon. Will mention a slight chance. With more sun expected,
temperatures will be closer to normal for highs on Friday. Forrester
.LONG TERM...Fri night through Wed...
A sharp cut-off low moves into Montana and increases the chance
for a severe thunderstorm late Sunday. The ECMWF shows the best
chance of this happening and seems reasonable given that it`s been
a wet summer and the GFS seems a bit too optimistic. Added mention
of gusty winds and small hail for now. Rest of forecast looked
Relatively dry and benign weather conditions are anticipated for
the weekend as an upper ridge influences eastern Montana while a
trough deepens across the Pacific Northwest. Given higher heights
with the ridge expect warm temperatures with highs largely into
Models continue to diverge a bit on the handling of the trough but
overall consensus is building toward having the trough gradually
push east and bring about increasing chances for showers and
thunderstorms by about Tuesday or Tuesday night. How much will
depend more precisely on the track/placement of the upper low as
well as timing. Once this feature pushes through along with a
surface cold front, expect a general cooling trend into the middle
part of next week. Maliawco
VFR flight conditions...outside of thunderstorms.
The trend through the terminal forecast cycle will be for isolated
thunderstorms creating some localized lower flight conditions
through the period. Mostly VFR elsewhere through the period.
Wind will continue to be northeast across the region under 15
knots...and variable and gusty winds in and around thunderstorms.