Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 241400

Area Forecast Discussion
National Weather Service Bismarck ND
900 AM CDT Mon Oct 24 2016

Issued at 858 AM CDT Mon Oct 24 2016

Fog persists in the James river valley and current forecast
carries this through 11 am. Otherwise current forecast trending
ok with mainly updates to current conditions.

UPDATE Issued at 622 AM CDT Mon Oct 24 2016

Areas of fog continue over eastern ND but weather cameras and
surface observations over eastern portions of central ND show
little in the way of fog, except for Jamestown which has been
going back and forth between a mile and a quarter mile most of the
night. Currently we are carrying patchy dense fog over this area
through mid morning in the gridded forecast. If fog spreads may
issue a sps but will leave things as is for now. Otherwise no
significant changes to the going forecast.


.SHORT TERM...(Today and tonight)
Issued at 334 AM CDT Mon Oct 24 2016

Focus in the short term is fog and low stratus cloud formation this
morning. Attention then turns to the potential strength of the
southeast winds.

Currently...surface high pressure was over the Red River Valley,
centered over the border of ND/MN. Temperatures had dropped into the
mid 20s/lower 30s there with light winds, and fog had begun to form
over parts of the eastern third of ND, including the Devils Lake
Basin and James Valley. The latest iterations of the short term high
res HRRR model seems to have a good handle on the current area of fog
formation, suggesting that the area along and east of the Coteau is
most at risk for dense fog. This model also suggests the fog will
linger into the later morning hours. After collaborating with Grand
Forks and Aberdeen NWS offices, and noting that web cams not yet
indicating any widespread fog, decided that we will mention patchy
fog north central, and patchy dense fog from the James Valley to the
Devils Lake Basin counties. Should dense fog develop, we can issue a
short term Special Weather Statement to address more widespread low

Meanwhile, at upper levels a strong ridge was established over the
Rockies. This upper level ridge axis is forecast to move east into
the Dakotas tonight. Broad surface low pressure over the Rockies,
and high pressure moving east today will allow southeast winds to
develop. A strong low level h925/h850 jet is forecast to develop
from the southern Plains northward into Saskatchewan by this
afternoon. Expecting southeast winds to be a bit stronger than the
model blends, and raised wind speeds to 15 to 20 mph with gusts to
25 mph - beginning late this morning and continuing through the
afternoon. Bufkit soundings indicate that the low level jet remains
strong tonight and possibly continues to mix out at the surface at
times, but noted that a low level inversion develops and may keep
the higher winds aloft from mixing. Confidence is not high enough to
keep those higher wind speeds mentioned tonight.

.LONG TERM...(Tuesday through Sunday)
Issued at 334 AM CDT Mon Oct 24 2016

Focus in the long term is on the chances for rain Tuesday into

The upper level ridge over the Dakotas Monday night begins to
flatten out as it moves east. Southwest flow aloft becomes
established over the Rockies with a large-scale upper level low off
the west coast. A shortwave emerging from the 4-corners area moves
northeast through the flow Monday night and reaches the Dakotas
Tuesday morning. This wave will bring an increase of mid level
moisture, and lifting associated with the established low level jet
will result in rain showers over central and eastern ND. At this
time it appears that the James Valley and into eastern ND are poised
to receive the bulk of the rainfall...with the possibility of
anywhere from 0.10 to 0.50 inches of rain.

Another shortwave emerging from the west coast system emerges from
the Pacific Northwest on Tuesday and reaches southern Saskatchewan
Tuesday night/Wednesday morning. Today`s model runs suggest that
showers from this wave will remain north of the Canadian border on

The western ridge builds back over the Rockies Thursday, with yet
another series of shortwave breaking down the ridge. Models are not
in good agreement regarding the timing and track of these
shortwaves. Model consensus suggests keeping any mention of
precipitation out of the forecast for the end of this week, with
only slight chance mentions on Saturday.

Continued mild with highs in the 50s and 60s this week. A cooler
weekend ahead with highs in the 40s and 50s.


.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 622 AM CDT Mon Oct 24 2016

IFR cigs/vsbys continue at KJMS at 11 UTC. Will carry IFR fog/cigs
through 16 UTC. Farther west, HRRR has been keying on low stratus
over central ND since before 06 UTC. Nothing had developed all
night long but just at 11 UTC KHEI reported a ceiling of 200 ft.
Hard to tell on fog loop with high clouds over the area but there
may be some more patchy stratus starting to develop. Will take
one last look but might just carry a scattered ifr layer, with no
ceiling to hint at the possibility if ifr cigs until we see
something more definitive. HRRR has this low stratus through
around 15-16 UTC before burning off. Otherwise today after any
fog/stratus burns off this morning, we expect VFR conditions with
mainly mid and high level clouds and an increasing southeast flow,
becoming gusty this afternoon. A system moves in late tonight with
perhaps a few showers at KBIS and KJMS after 06 UTC but ceilings
are forecast to remain VFR through 12 UTC Tuesday. Ceilings do
appear to lower rapidly across central ND after 12 UTC Tuesday.




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