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Area forecast discussion 
National Weather Service Glasgow Montana
217 PM MDT Thursday Jul 28 2016

Short term...for northeast Montana...tonight through Sat...

A shortwave trough in the northwest flow aloft could produce an isolated
shower or thunderstorms in the south this evening. Otherwise, high
pressure will build into northeast Montana tonight with mainly dry
weather.

A shortwave trough moves across Saskatchewan and northeast Montana
on Friday. There may be enough instability with it to initiate
some weak convection across the area mainly in the afternoon. Will
mention a chance or slight chance of showers and thunderstorms in
most areas.

A weak ridge moves into the area Friday night and Saturday with
dry weather. Conditions. That ridge will lead to warmer
temperatures on Saturday as highs will be 90 in most areas.

Long term...Sat night through Thu...

Medium range models continue to show a divergence of solutions
with the European model (ecmwf) showing slower solutions while GFS is faster. The
two periods that seem to be the most critical are late Sunday and
late Tuesday. If the European model (ecmwf) solution wins, then severe thunderstorm
chances will occur over the eastern zones. If the GFS wins, then
these storms will form over North Dakota. The Storm Prediction
Center doesn't have anything pinned down yet either so will
continue to monitor.

Otherwise, blended current forecast grids a bit with 12z guidance.
Tfj

Previous discussion...
weak westerly flow with embedded shortwaves sliding along the
Canadian border continues through next week. This will result in
the occasional thunderstorm and generally mild temperatures.

Thermal ridge builds into eastern Montana over the weekend pushing
some temperatures into the 90s as an upper trof swings through
western Canada. Frontal boundary pushes across the state early on
Sunday pushing low level southeast flow into the Dakotas. With the
deflection of the plains moisture feed and the shallowness of the
upper wave, main threat for stronger thunderstorms will be near or
across the North Dakota border Sunday afternoon and evening.

Heights lower on Monday with the passage of the upper wave through
the Canadian prairies before another thermal ridge pushes into the
Treasure state on Tuesday. Another shortwave trof pushes through
the region midweek. Models in decent agreement with pulling the
wave south of the border and bringing better moisture into the
state to produce thunderstorms with the frontal passage Tuesday
night into Wednesday morning, although there are some timing
differences.

Cooler weather follows behind this midweek trof before ridge
begins to rebound to the west. Ebert



&&

Aviation...
VFR.

Cumulus clouds are expected to diminish this evening. A disturbance
moving east across southern sask may touch off a shower or
isolated thunderstorm late Friday.

Winds: light southeast at 10 kts or less tonight then variable at
generally less than 10 kts Friday. Tfj



&&

Glasgow watches/warnings/advisories...none.

&&

$$

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