Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 010259

Area Forecast Discussion
National Weather Service Bismarck ND
959 PM CDT WED AUG 31 2016

Issued at 952 PM CDT Wed Aug 31 2016

The forecast remains on track and blended to observed trends
through 02 UTC.

UPDATE Issued at 655 PM CDT Wed Aug 31 2016

No significant changes with this update other than to blend to
observed trends through 23 UTC. Ongoing convection is expected to
continue to weaken through sunset across the far upper James River


.SHORT TERM...(This evening through Thursday)
Issued at 314 PM CDT Wed Aug 31 2016

Latest radar and satellite imagery indicates the band of showers
and thunderstorms across central north dakota continues to slide
slowly east as warm advection coincides with an uncapped unstable
atmosphere. Stronger capping is keeping convection at bay to the
west. Have extended this area of showers and thunderstorms through
the afternoon and early evening over the far southeast CWA as this
narrow axis continues to work eastward.

After this moves out of the CWA is is expected to be relatively
quiet. Although a stray thunderstorm can not be completely ruled
out, thunderstorm activity is expected to be limited until
Thursday night. Late tonight and Thursday we will see an
increasing surface gradient and increasing southerly inflow over
western ND in response to a digging trough off the Pacific
Northwest Coast. It looks like marginal winds for possible wind
advisory. Will also need to monitor fire weather issues. the axis
of lower humidities shifts farther east into central ND where
grasses are much greener. In the far west where grasses are curing
more quickly or completely cured, the relative humidities are much
higher as return moisture lifts into this area.

Thursday night through Friday night the upper trough moves onto
the west coast and then into southern British columbia. This will
keep a southwest upper flow and periodic thunderstorm chances
through this period, mainly across the west and north central
North Dakota.

.LONG TERM...(Thursday night through Wednesday)
Issued at 314 PM CDT Wed Aug 31 2016

Previous trends of an active/unsettled weather pattern remains on
track through the extended period.

Current water vapor imagery shows a closed upper low circulating off
the British Columbia coastline. This low will slowly move northeast
through Sunday. In doing so, a persistent southwest flow aloft with
multiple shortwaves will impact western and central ND. At the
surface a cold front will be sliding slowly into central ND Saturday
morning, and not clearing the far southern James River Valley until
Sunday afternoon. Low pressure is still forecast to develop along
the frontal system Saturday afternoon in north central South Dakota,
and then translate northeast through Sunday evening. Saturday still
looks like the greatest threat for strong to severe thunderstorms
for portions of central ND including the James River Valley during
the afternoon and evening.

For Saturday night through Sunday, as the surface low rides
northeast along the front, expect widespread high chances to likely
pops for southern ND. Most unstable cape decreases to a couple
hundred joules in the far southern James River Valley, thus thunder
looks minimal at this time.

The pattern becomes increasingly wet once again Monday through
Tuesday as the next shortwave trough shifts through from west to

Per GFS and ECMWF, there appears to be successive quick moving
shortwaves shifting through Wednesday and beyond for periodic
chances of showers and thunderstorms.

Expect a cooling trend Sunday through Wednesday with highs in the
upper 60s to lower 70s.


.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 952 PM CDT Wed Aug 31 2016

VFR conditions are forecast for the 00 UTC TAF cycle. Low level
wind shear may be possible at KDIK late tonight into early
Thursday morning. Otherwise, strong southeast winds with gusts of
30 to 35 kts are forecast at KISN/KBIS/KMOT/KDIK late Thursday
morning through the afternoon.


.BIS Watches/Warnings/Advisories...


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