Area Forecast Discussion
Issued by NWS Glasgow, MT

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FXUS65 KGGW 260303

Area Forecast Discussion
National Weather Service GLASGOW MT
903 PM MDT MON JUL 25 2016

.SHORT TERM...for northeast Montana...tonight through Wed...
No update tonight. High pressure continues to dominate the area. A
few thunderstorms are moving into the southwestern zones. Looks to
be only garden variety storms. Few changes made. Proton

Synoptic setup: a large high pressure heat dome continue to be
stationed over the western half of the conus with its center
positioned over the Nevada/Utah border. North of this zonal flow
exists across southern Canada and the far northern CONUS. Weak
shortwaves are constantly flowing though this stream along with
Pacific to Monsoonal Moisture.

Tonight and Tuesday: Ridge across the area earlier today has
toppled and allowed weak southwest flow to enter the area. A
shortwave is expected to move through central and eastern Montana
tonight into Tuesday morning and bring isolated nocturnal showers
and thunderstorms. At this time we are hedging the bets that it
will move along the BYZ/GGW border through the late evening and
morning hours. While the upper level wave will exit by the
afternoon, enough remnant moisture will remain with peak heating to
cause even more showers during the afternoon.

Tuesday night into Wednesday: Right on the heels of the previous
shortwave an even larger shortwave will arrive during the
overnight periods dragging along a weak surface cold front. This
will drive daytimes highs down about 5 degrees, but also bring
greater chances at widespread hit and miss convective rain
showers. A tenth to a quarter of an inch of QPF may be possible
with this passage.  GAH

.LONG TERM...Wed night through Mon...

The forecast is still in great shape, and the model runs from 1200
UTC and 1800 UTC in general keep the same large-scale patterns
over the western CONUS and provides similar levels of confidence
in the long term such that no major changes are warranted this


Previous Discussion:
Northwest flow aloft will prevail from Wednesday Night through
Friday. Frequent shortwaves are expected which will bring chances
for showers and thunderstorms.

An upper ridge builds into the area Friday Night and Saturday with
dry and warmer weather.

The ridge moves to the east on Sunday and flow aloft turns to the
southwest. Shortwaves within the SW flow aloft will bring
chances for showers and thunderstorms that will continue into
Monday. Forrester


Synopsis: A high pressure ridge will move to the east today with
mostly clear skies and excellent flying weather through the early
evening. A disturbance tonight will bring mid and high level
clouds with an isolated shower or thunderstorm near KGDV and KSDY
after 06Z.

Winds: Light and variable winds this morning, will become north
at 5 to 10 knots this afternoon, and then veer northeast 5 to 15
knots tonight.





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