Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 211741

Area Forecast Discussion
National Weather Service Bismarck ND
1241 PM CDT Tue Mar 21 2017

Issued at 1241 PM CDT Tue Mar 21 2017

Updated to blend observed trends to afternoon forecast. Only change
was to add a slight chance mention of light snow south of I-94 south
of the Jamestown area for a few hours this afternoon. Band of lower
clouds with persistent light snow reported at Jamestown. This band
moving south and should be south of the ND/SD border by late

UPDATE Issued at 933 AM CDT Tue Mar 21 2017

Quick update to blend to observed trends through 14 UTC.

UPDATE Issued at 642 AM CDT Tue Mar 21 2017

Forecast is on track and only blended current obs into the
forecast. Bowman radar continues to show echoes near the SD
border. Have not seen any obs from Hettinger indicating anything
reaching the ground there, though ceilings briefly dropped to 800


.SHORT TERM...(Today and tonight)

Issued at 430 AM CDT Tue Mar 21 2017

The main forecast highlight in the short term period will be
colder temperatures today.

Currently, cold surface high pressure over Saskatchewan and
Manitoba building southward into central and eastern North Dakota.
Some low stratus and a few flurries accompanying this cold air
push mainly over the eastern third of the state. Light
precipitation in the form of snow continues over the far southwest
near a frontal zone and underneath a mid level impulse moving
east-southeast. Utilized a blend of the latest NAM with our
consensus short term guidance for pops/qpf, and could see some
light snow accumulations in grassy areas.

Light snow over the far southwest will taper off 12-18Z as forcing
diminishes. Main story today will be colder temperatures as high
pressure continues to build south over the Eastern Dakotas and
Upper Mississippi Valley. Highs today will only reach the low 20s
north central and low to mid 30s elsewhere.

Southerly return flow ramps up quickly later today and especially
into tonight west and central along with upper level ridging
aloft. Light precipitation will be possible far south with
favorable LLJ dynamics and as several embedded impulses lift
across the Dakotas. Thermal profiles suggest snow.

.LONG TERM...(Wednesday through Monday)

Issued at 430 AM CDT Tue Mar 21 2017

The extended period will be highlighted by a continued
progressive flow pattern.

An upper level ridge axis will be over the region at the beginning
of the long term period Wednesday. Embedded S/WV cuts through the
ridge coupled with a warm frontal zone moving east across the
Dakotas to bring a chance for rain or snow during the day
Wednesday. Ridge moves east Wed night allowing south/southwesterly
flow to develop ahead of a potent upper level trough/closed low
over the Great Basin. Lead S/WV ejects through the flow across the
Dakotas late Wed night into Thursday bringing a chance for
precipitation to our areas. Thermal profiles suggest a window of
freezing rain possible, so this was added/maintained in the
gridded forecast along with mentioning in the HWO and SFP. Upper
low moves eastward across the Central Plains with best
precipitation chances across the southern half of the state on
Thursday mainly in the form of rain as models have trended a bit
warmer. Active pattern then continues through the weekend though
with much uncertainty given large model spreads.


.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1241 PM CDT Tue Mar 21 2017

MVFR stratus across the James River Valley impacting KJMS will move
south this afternoon and scatter out at KJMS by 18z/19z. This band
may affect KBIS after 19z and had already stretched northwestward
towards KMOT. A few pockets of MVFR stratus across southwest North
Dakota will continue for much of the day. MVFR stratus expected to
expand back north into southwestern ND...eventually reaching KBIS
and possibly into KISN. Winds to become southeasterly and increase
tonight and Wednesday with gusty winds through Wednesday. Light snow
or rain possible Wednesday, but too far out in the TAF forecast to
mention directly in TAFs for this forecast package.




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