Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 241443
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
943 AM CDT Sat Sep 24 2016

.UPDATE...
Issued at 943 AM CDT Sat Sep 24 2016

Made a few adjustments with the update to extend fog across the
west and north. Based on web cams and some obs, it is eroding at
some locations but slower than expected. HRRR tries to hold onto
fog into early afternoon across the west. Also expanded low pops
across parts of south central ND with some showers continuing to
move through the area.

No changes with latest SPC day 1 outlook with a marginal risk
covering portions of our east. There will be a window of
opportunity during the afternoon for some strong storms. NAM
continues to be more aggressive with instability, showing up to
2500 J/KG of CAPE mid afternoon from James River Valley through
northcentral ND, with GFS not quite as unstable. Latest HRRR
however does not show much convection across our east.

UPDATE Issued at 655 AM CDT Sat Sep 24 2016

Did an update to pops and sky cover to account for convection
passing just west of the Mandan / Bismarck area. Otherwise no
changes to the inherited forecast.

&&

.SHORT TERM...(Today and tonight)
Issued at 450 AM CDT Sat Sep 24 2016

The mid level low was on the forecast track of the NAM and it was
followed more closely this forecast cycle. Temperatures today
will have a wide range from the cloudy, showery Divide County to
where the sun breaks out in Logan County.

Mid level low was moving through Wyoming this morning toward North
Dakota with its surface feature out ahead. As the circulation
approached, showers were moving more northwest, caught in the
circulation. With no returns upstream and the short term hi res
HRRR showing no showers for much of the morning, have dropped pops
all but the west and north. The central part of the forecast area
breaks into some sunshine this afternoon in the dry slot. CAPE and
instability increase in warm air advection and support
thunderstorm development in central North Dakota. As the storms
move northeast they`ll encounter increasingly unstable air and sub
severe hail and wind will become a concern. Any severe weather
should be very limited in the Bismarck NWS forecast area and
confined to low end severe if it reaches that level at all.

Concern for tonight is the next short wave moving through the
circulation with another round of showers, maybe a rumble of
thunder. As the surface low moves through the wind shifts and
increases. Bufkit soundings for southwest North Dakota show steady
30 to gusts 45 mph of wind will reach the surface. There is
higher wind than that aloft and it is possible this could mix
down to the higher terrain southwest. For now will go with
advisory for winds 30 to 45 mph and keep the high wind warnings
in our toolbox until we see the whites of its eyes. Any showers
will act to mix that higher wind to the surface so we`ll have to
monitor closely.

.LONG TERM...(Sunday through Friday)
Issued at 450 AM CDT Sat Sep 24 2016

Showers taper off west early Sunday as the cyclone pulls away and
becomes an open wave, but the wind will be left behind. Have
continued the wind advisory for the southwest through Sunday but
wouldn`t be surprised if the Sunday day shift can cancel it a bit
early. Generally cooler and windy to very windy Sunday, but with
increasing sunshine from the west.

After that an H5 ridge builds over the area and much of the coming
work week is dry and mild with lows in the 40s and highs 65 to 75.
The coolest night starts the period, Sunday night-Monday morning,
with a lot of places dipping into the upper 30s.

The next rain producer looks to come in late in the week and into
next weekend.

&&

.AVIATION...(For the 12Z TAFS through 12Z Sunday night)
Issued at 655 AM CDT Sat Sep 24 2016

Widespread IFR/LIFR conditions in stratus and fog will continue
across many parts western and central North Dakota through
Saturday morning. Conditions will improved to MVFR to VFR mid-day.
A cold front will move through overnight with gusty winds in its
wake, with a reduction in cigs to IFR/MVFR possible.


&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 5 PM this afternoon to 5 PM MDT Sunday for
NDZ040-041-043-044.

&&

$$

UPDATE...JNS
SHORT TERM...JPM
LONG TERM...JPM
AVIATION...JJS



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