Area Forecast Discussion
Issued by NWS Glasgow, MT
FXUS65 KGGW 291519 AAA
Area Forecast Discussion...UPDATED
National Weather Service GLASGOW MT
919 AM MDT Wed Mar 29 2017
.SHORT TERM...for northeast Montana...today through Fri...
Morning update: Adjusted the near/short-term forecast to account
for the latest model consensus. Sunny skies today in-between
cloudy periods. More clouds approaching from the west later this
afternoon and evening with strengthening west winds up to 15 mph.
Previous short term discussion: Shortwave trough currently over
eastern Montana will move to the east and shortwave ridge on
nearly zonal flow aloft will build into the forecast area this
afternoon and evening. This will allow for a dry day with partly
cloudy skies. Patchy fog is possible this morning in the northeast
part of the forecast area with wet ground from recent rains.
The dry weather will continue tonight over the area with an
increase in mid and high clouds as the flow aloft turns to the SW
ahead of an upper trough that will be moving inland from the
Pacific. The base of that trough will drop south into the desert
southwest on Thursday and the SW flow ahead of this trough will
bring deep moisture into Northeast Montana. Rain showers will
develop from SW to NE across the region Thursday and Thursday
The trough in the SW US becomes a closed low Thursday Night.
Northeast Montana will transition from the SW flow aloft of the
southern stream to a west to NW flow aloft in the northern stream.
Moisture will linger over the area on Friday with a good chance of
rain showers until a shortwave trough in the northern stream
pushes the moisture to the east Friday afternoon and evening.
.LONG TERM...Fri night through Wed...
The extended period begins Friday night into the weekend with
largely dry zonal flow aloft across the northern High Plains while
a trough begins to dig into the Pacific Northwest.
The trough will amplify early next week and shift east with models
bringing the trough axis over eastern Montana by late Monday
evening. This will offer plenty of dynamic forcing for ascent to
justify chance pops for much of the CWA.
While models differ on timing, some indications are that the
trough will head downstream while a ridge amplifies across the
western CONUS for the middle and end of next week with a return to
dry and warm weather conditions. However, there is enough
uncertainty in the ensemble members that keeping in slight chances
for pops in line with consensus model blends still makes sense at
Expect VFR to prevail. West winds will increase this afternoon at
10 to 15 kts.