Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 251127

Area Forecast Discussion
National Weather Service Bismarck ND
627 AM CDT Mon Sep 25 2017

Issued at 617 AM CDT Mon Sep 25 2017

Clouds cover all but the far northwest corner of Divide county
this morning. So far fog does not appear to be a problem. Based on
Bowman radar slowed the progress of showers into southwest this
morning. Otherwise current forecast looks good.


.SHORT TERM...(Today and tonight)
Issued at 329 AM CDT Mon Sep 25 2017

Surface high pressure was over the border of western ND and
Montana. Meanwhile the main upper level trough was over the US
Rockies with the low center over western Wyoming. The models are
indicating some upper level impulses ejecting northeastward from
Colorado and eastern Wyoming, reaching southern ND before
daybreak. Regional radars depict showers and some thunderstorms
moving northward from central Wyoming, South Dakota, Nebraska,
southern Minnesota at 2 am cdt. The upper level energy impulses
continue moving northward today as the upper low lifts northeast
into eastern Montana this afternoon, and the western Dakotas
Monday night. Thus will keep the mention of spotty showers after
daybreak over parts of western and central North Dakota. Better
chances of showers tonight over eastern portions of central North
Dakota, namely from the James Valley into the Turtle Mountain
area, with more substantive upper level impulses arriving as the
low/trough lifts northeastward into the Dakotas.

.LONG TERM...(Tuesday through Sunday)
Issued at 329 AM CDT Mon Sep 25 2017

By daybreak Tuesday the upper level longwave trough is forecast to
have lifted northeastward into the western Dakotas, and continue
lifting northeastward to western Ontario by Wednesday morning. Model
consensus keeps a chance of showers over central ND Tuesday morning,
with clearing from west to east. Continued cool with highs from the
50s central to lower 60s in the west.

As the longwave trough exits our area, the upper level flow becomes
northwesterly as a ridge builds over the west coast. A shortwave in
the upper flow dives southeast and grazes the northeast half of
North Dakota Wednesday night. Thus only a slight chance mention of
showers for mainly the Turtle Mountains Wednesday night.

Otherwise gradual warming for North Dakota as the western ridge
builds east across the Rockies with dry weather. We should see high
temperatures in the 60s - sometimes into the lower 70s - Wednesday
through Sunday. In general, overnight lows are expected to be in the
40s during this period, but there is a chance for a touch of frost
Tuesday night and again on Thursday night, with temperatures
dropping into the upper 30s Tuesday night in the southwest, and
Thursday night over parts of western and central North Dakota.

The next chance of showers looks to be Saturday night into Sunday.
The upper level ridge is forecast to move east across the Dakotas
Friday night, and the remnants of a cut-off low over the desert
southwest lifts northeast across the Dakotas Saturday night. This
will be followed by another transitory longwave trough moving east
across central North America Sunday/Monday.


.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 617 AM CDT Mon Sep 25 2017

Hazards for the 12Z aviation forecast include MVFR ceilings
KDIK-KBIS-KJMS today. Weak upper level low will move into western
South Dakota today and spread scattered showers across western
North Dakota. No visibility restrictions expected.




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