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000
FXUS63 KBIS 261733
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1233 PM CDT Tue Sep 26 2017

.UPDATE...
Issued at 1227 PM CDT Tue Sep 26 2017

A few light showers continue to linger across the forecast area.
High resolution guidance still suggests that this activity will
remain around the forecast area through the afternoon and early
evening, gradually diminishing from west to east. Visible
satellite imagery has show some recent breaks in the clouds, most
notably in the far west. Therefore, decided to decrease cloud
cover and progress clearing earlier than initial forecast. The
15z in house National Blend of Models appeared to have a good
handle on the current sky cover, so went with that solution
blended with the previous forecast. Finally, the latest
observations were blended to the going forecast.

UPDATE Issued at 904 AM CDT Tue Sep 26 2017

Isolated to scattered showers will remain possible through the
afternoon as an upper level low continues to spin across western
North Dakota. Clouds and precipitation will gradually diminish
from west to east through the day. For this update, just tweaked
precipitation chances based on radar trends and the latest high
resolution guidance and slightly upped winds using CONSMOS.
Otherwise, just blended the latest observations to the going
forecast.

UPDATE Issued at 646 AM CDT Tue Sep 26 2017

GOES16 water vapor and radar trends through 1142 UTC show an
increase in shower activity across the James River Valley over
the past hour in a zone of steeper mid level lapse rates ahead of
the upper low across the North Dakota and Montana border. Near
term PoPs were adjusted to match these trends, in addition to
shallow shower activity across the southwest as observed on
the ND ARB Bowman radar.

&&

.SHORT TERM...(Today and tonight)
Issued at 319 AM CDT Tue Sep 26 2017

Rain showers today and possible frost southwest tonight are the main
concerns in the short term.

Satellite pics indicate the upper level low was centered
at the border of Montana/North Dakota, with low and mid level clouds
streaming northward through the Plains ahead of the system, and some
wrap around clouds circulating around the low extending into
eastern Montana. Showers continued streaming northward over eastern
Nebraska/South Dakota and into southeastern North Dakota in
association with a series of upper level impulses ahead of the low
moving northward from the base of the low.

The upper level low is forecast to move northeast across North
Dakota and southern Manitoba, reaching western Ontario by this
evening, continuing northeast between the Great Lakes and Hudson
Bay. As this occurs, a dry northwest upper level flow will develop
across North Dakota tonight.

Chances of showers will continue this morning across western and
central North Dakota, with the best chances of rain showers in the
James Valley. This afternoon as the upper low exits to the
northeast, look for decreasing clouds and decreasing rain chances
from west to east. Highs today should range from the lower 60s west
to lower 50s in the Turtle Mountain area.

Tonight we should see mainly clear skies south and partly cloudy
skies north as a weak impulse in the northwest flow aloft traverses
our area. Frost is possible over parts of southwestern North Dakota,
where lows tonight are expected to be in the mid and upper 30s.
Patchy frost in the southwest may occur for a couple of hours just
before sunrise...and is not expected to be widespread. Therefore
will mention patchy frost. Do not think a frost advisory is
warranted, but the day shift may need to revisit this with the next
set of model runs.

.LONG TERM...(Wednesday through Monday)
Issued at 319 AM CDT Tue Sep 26 2017

Quiet weather expected through the week as an upper level ridge
builds into the region, bringing dry conditions and a return to
seasonal temperatures. The ridge axis moves east across central
Canada later this week, and the next low pressure system arriving at
the west coast on Friday moves east across the Rockies Saturday,
expanding into central North America through early next week. This
will bring off and on chances of showers to our area Saturday night
through early next week.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1227 PM CDT Tue Sep 26 2017

Widespread MVFR cigs will gradually improve to VFR through this
afternoon into early this evening. VFR conditions will then
prevail.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...ZH
SHORT TERM...JV
LONG TERM...JV
AVIATION...JJS