Area Forecast Discussion
Issued by NWS Glasgow, MT

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FXUS65 KGGW 281455

Area Forecast Discussion
National Weather Service GLASGOW MT
855 AM MDT SAT MAY 28 2016

.SHORT TERM...for northeast through Mon...

Morning Update... a north south oriented band of rain is moving
from west to east across the area CWA. PoPs were adjusted to
better hit the timing of this passage. While there is some chance
for thunder, the only places that currently have thunder in this
line are well north of the international border under cooler
taller cloud tops than what are currently over the CWA. So while
rain is a definite with the passage only a slight chance for
thunder exists. A well moistened boundary layer is also allowing
for some mist/fog with the passage of the event as well. GAH

Previous Short Term Discussion...
The day begins with a cold front lined up north-south across the
western zones. The front is associated with an upper trough
centered over Southern British Columbia. Flow aloft over Northeast
Montana will be southerly to southwesterly which will direct
moisture across the front. This will produce a narrow area of
moderate rain. Convective parameters become moderate by noon which
will initiate general thunderstorms along with the rain showers.
As the front and best lift progress east so does the convection
and rain. By early evening the trough lifts back north into
canada, allowing flow aloft to become westerly and ending the
showers and thunder.

Conditions remain unchanged for Saturday night and Sunday with
this western flow. Therefore expect pleasant weather conditions
with temperatures moving above average. Then conditions begin to
change again Sunday night as another trough drops into the Pacific
Northwest. Once again flow aloft backs to the southwest to bring
in more moisture and instability. Showers that begin after
midnight will become more widespread for Monday. The trough will
dig into Northeast Montana which will begin to increase winds as
the storm attempts to stack up over the area. With a more
energetic wind profile, some storms may become more vigorous with
the possibility of some dry slotting by afternoon. Expect
temperatures to return to near normal.


.LONG TERM...Mon night through Sat...

Upper low will be over Eastern Montana Monday Night. This low will
combine with an inverted surface trough and deep moisture to bring
showers with embedded thunderstorms to the forecast area. This low
will move into North Dakota on Tuesday and back side wrap around
moisture will remain over Eastern Montana the entire day with
showers and embedded thunderstorms continuing.

Tuesday Night and Wednesday, the low moves to Minnesota and upper
ridge moves into Western Montana. Drier air moves into the
forecast area allowing the showers to diminish.

The upper ridge moves into Eastern Montana on Thursday with warmer
temperatures and dry weather.

A weak shortwave trough Thursday Night and Friday will flatten the
ridge. With limited moisture, will maintain dry forecast. Ridge
rebounds on Saturday with warm and dry weather. Forrester



SYNOPSIS: A north/south oriented band of precipitation is
currently working its way from west to east.

VSBY: Reductions in visibility are sporadic with this passage but
dropping as low as 1 Mile with the heaviest rain showers at KGGW.
Some of which is actually more fog than rain with a highly
moistened surface layer. While KOLF may experience similar drops
in visibility, KSDY and KGDV are set at the southern edge of the
shower bands with far less precip and are more likely to
experience less obstruction with the passage of the shower band.

WIND: East winds around 10 knots will turn to the west with the
passage of the showers late this morning through this afternoon.
becoming light and variable overnight.





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