Area Forecast Discussion
Issued by NWS Glasgow, MT

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FXUS65 KGGW 271509

Area Forecast Discussion
National Weather Service GLASGOW MT
909 AM MDT Thu Oct 27 2016

.SHORT TERM...for northeast through Sat...

Update: The going forecast is in overall good shape. The only
adjustment made for the morning update was to add mention of
sprinkles in across portions of Valley, Phillips, and Garfield
counties as KGGW radar imagery is showing an area of very light
showers there. Gilchrist

Previous discussion:upper level ridge and thermal ridge will be
over Eastern Montana today. This will bring temperatures around 15
degrees above normal to the region with highs between 65 and 75 in
most areas. Mid and upper level moisture moving over the ridge
will continue to bring cloud cover although there will be breaks
at times today.

The ridge axis moves to the east this evening turning the flow
aloft to the southwest. A shortwave trough will move along the
MT/SK border tonight and bring a cold front through Eastern
Montana. Most of the moisture with this system stays to the north.
Will only mention a slight chance of showers near the Canadian
border tonight.

Cooler and mainly dry weather will prevail on Friday with
Northeast Montana between system. Breezy NW winds are expected but
wind speeds should stay below lake wind advisory criteria.

A shortwave moves northeast from Idaho into Southern Montana
Friday Night. Meanwhile, there will be a surface high over
Saskatchewan. The flow aloft by Friday Night becomes more zonal
which will keep most of this moisture south of the forecast area.
Will limit chance of rain showers to the southern edge of the
forecast area.

Surface high builds south into Northeast Montana on Saturday. A
chance of showers could linger into the morning in the south.
Otherwise, look for dry weather with temperatures near normal.

.LONG TERM...Sat night through Thu...

The extended forecast period starts off Saturday evening with a
an upper level ridge axis in place over Northeast Montana. There
will be a large Pacific trough nudged up against the coast from
Northern California to Vancouver Island. The base of this trough
will eject Pacific moisture into the Northern Rockies Saturday
night. Some of this moisture will end up in isolated to scattered
showers over the region, but Nemont will remain mostly dry.

By late Sunday the base of the trough moves across Northern
California into the Great Basin. Additionally a short-wave
disturbance moving across the Prairie Provinces will send a cold
front south into Montana. The combination will result in
widespread rain over much of Montana Sunday night into Monday, and
possibly Monday evening. 850mb temperatures below 0C stay to the
north, so expect precipitation to be rain.

Tuesday and beyond a trough moving through Alberta and
Saskatchewan will send another cold front south into Nemont, but
this time the 850 mb temperatures drop below 0C. Additionally
northwest to north winds develop, wind strength aided by the CAA.

Ridging returns Wednesday to a return to more seasonal




Plentiful Pacific moisture is riding up and around an upper-level
ridge over the region today. A warmer than average day is expected
in spite of the persistent cloudiness. Later tonight, a short-
wave disturbance in the flow will send a cold front into the local
area. The main effect will be increased low level clouds and
possibly a few rain showers.

Flight Conditions:  VFR

Southeast wind around 10kts will veer around to the northwest





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