Area Forecast Discussion
Issued by NWS Glasgow, MT

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FXUS65 KGGW 301504

Area Forecast Discussion
National Weather Service GLASGOW MT
904 AM MDT MON MAY 30 2016

.SHORT TERM...for northeast through Wed...

Morning Update...
Change to the forecast this morning again focused on PoPs.
Pressure analysis is showing that the upper level front has passed
through the CWA with most of the showers being post frontal.
However satellite water vapor imagery is placing the center of the
trough and associated vorticity lobe over northwestern Montana
with a dry slot rapidly being pulled into eastern Montana and
having already nosed into the southeastern sections of the CWA.
This dry slot will rapidly push through the area allowing a 6 to 9
hour period of drying before the second wave or rain drops down
the backside of the low from the north near or after midnight. The
few thunderstorms that managed to develop south of a baroclinic
leaf over the southwestern CWA/Yellowstone Valley should be out of
the area within the next 3 hours if not sooner. GAH

previous short term discussion...
The upper trough drops into the Northern Rockies and the Montana
plains today sending a cold front ahead. The trough closes off as
it reaches Northeast Montana this evening. Cooler temperatures
will move in with it with highs in the 50s and 60s. Expect periods
of scattered showers through today and tonight, but only up to a
few tenths of an inch of QPF. With surface winds and winds aloft
all lining up from the northwest, expect 15-25kt wind with gusts
to 35kt during the afternoon. With sustained strong winds expect
to ramp up around noon and continue through early Tuesday evening,
will issue a wind advisory for Fort Peck Lake. Weak to moderate
convective parameters set up over the Dakotas this afternoon and
possibly along and southeast of the Yellowstone River. However by
the time of peak heating this convective area should have moved
totally into the Dakotas, so expect only isolated to scattered
general thunderstorms.

Majority of the rain should fall after midnight and Tuesday
morning when a low wraps up with a trowal on the back side of the
low when begins to stack up and positions itself over North
Dakota. With the scattered nature of the rain showers and dry
slotting, expected QPF totals are not as high as previously seen
in the models.

Tuesday night and Wednesday, rain will have moved east out of the
local area, but northwest flow will keep the night cool. Wednesday
a dry warm front will be approaching the area to begin a warming
trend. Highs will return to normal.


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

A flat ridge in nearly zonal flow aloft is expected Wednesday
Night and Thursday Morning. A shortwave trough in zonal flow aloft
Thursday afternoon and evening will bring a warm front through the
area. Moisture will stay to the north of Montana with this system.
Will maintain dry forecast.

The upper ridge builds over the western US and Canada starting on
Friday and strengthens over the weekend. Expect warm and dry
weather over the area. Forrester



SYNOPSIS: An upper trough is moving through Eastern Montana today
through Tuesday. A mix of mid clouds today will be replaced by
low clouds early morning Tuesday. A dry slot late this afternoon
and evening may only affect KGDV leaving the other terminals to
experience no and off showers before the second wave of rain
arrives after Midnight. Low MVFR/IFR clouds are then expected to
take hold.

BEYOND THE CYCLE: Ceilings heights in MVFR/IFR bare not expected
to lift until Tuesday afternoon.

WIND: West to northwest at 10 to 20 kts today and tonight...
veering to the north after sunup Tuesday.


Lake Wind Advisory until 9 PM MDT Tuesday For Fort Peck Lake for
Central and Southeast Phillips...Central and Southern Valley...


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