Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 271705

Area Forecast Discussion
National Weather Service Bismarck ND
1205 PM CDT Sat May 27 2017

Issued at 1150 AM CDT Sat May 27 2017

This forecast review resulted in a 2-4 degree increase in forecast
high temperatures for this afternoon based on current trends, and
a slight bump up in wind speeds from late morning into the early
afternoon based on those speeds increasing a bit earlier than
anticipated. As far as shower and storm chances, the potent H5
short wave continues to be forecast by mesoscale models to provide
the best mid level lifting from the Minot area through Jamestown.
There is convergence at the surface with the approaching wind
shift line but low level moisture is not impressive with dew
points generally 40 to 45. With that will continue to expect
shower and storm development north of Williston, tracking
southeast and increasing through the late afternoon. Highest
chances again Minot through Jamestown. Convection will be
scattered so hit or miss, and mostly miss. The wave moves out of
the forecast area around 10 PM with a quick change to strong
negative vorticity advection and a shut down of convection.

Issued at 836 AM CDT Sat May 27 2017

No change to forecast thinking for today with this update, which
was to blend to observed trends through 13 UTC and the latest CAM
trends through their 12 UTC iterations. Scattered rain showers and
thunderstorms will develop this afternoon with diurnal heating and
ahead of a potent vort lobe that will propagate southeast out of
Canada. Given inverted-v soundings and environmental winds, gusts
in excess of 40 mph are possible with the stronger showers and
storms this afternoon and early this evening. However, severe
weather is not expected.

UPDATE Issued at 634 AM CDT Sat May 27 2017

Only change needed for early morning update was to adjust cloud
cover up a bit over the southern James River Valley. Otherwise,
going forecast remains in good shape.


.SHORT TERM...(Today and tonight)
Issued at 422 AM CDT Sat May 27 2017

Current surface analysis places low near central Manitoba, with
high over the northern Rockies. Upper level analysis places low
over east central Manitoba, with ridge over the west coast.
Multiple short waves noted in the flow rotating around the low.

For today...a few weak showers will be possible this morning
primarily over northwestern portions of the area as a weak short
wave passes through. Greater shower chances will come this
afternoon throughout the area as a stronger wave rotates in.
Modest instability will be in place which could lead to a few
claps of thunder. Breezy conditions expected throughout the area
with moderate pressure gradient in place.

For tonight...precipiation chances will gradually taper from
northwest to southeast in the evening as the wave pushes out of
the area. Thereafter, a quiet evening is inspected.

.LONG TERM...(Sunday through Friday)
Issued at 422 AM CDT Sat May 27 2017

Upper low will meander towards the Manitoba/Ontario border on
Sunday, which will bring additional precipitation chances mainly
to central and eastern portions of the state, along with another
breezy day. Similar conditions expected for Memorial Day as the
low gradually creeps over Lake Superior.

Upper low continues its eastward push on Tuesday as ridge sets up
over the Rockies. Some models are bringing a weak wave through
central and portions of eastern North Dakota, though this appears
to be fast moving. With that said, will still go with a slight
chance of showers in the afternoon.

Ridge then slowly moves east through the end of the work week
before flattening towards the weekend, bringing a subtle warming
trend. Occasional weak waves slide through the areas bringing low
precipitation chances from time to time.


.AVIATION...(For the 18Z TAFS through 18Z Sunday)
Issued at 1150 AM CDT Sat May 27 2017

Scattered afternoon and early evening showers and thunderstorms
are forecast across western and central North Dakota. The higher
chances are from KMOT through KJMS. Northwest wind gusts as high
as 30kts will be common across the area until sunset.




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