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000
FXUS63 KBIS 212053
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
353 PM CDT Thu Sep 21 2017

.SHORT TERM...(This evening through Friday)
Issued at 307 PM CDT Thu Sep 21 2017

An upper level trough over the western U.S. into southern Canada
will influence the weather over the northern plains over the next
several days. Tonight, jet energy propagating through broad
southwest upper flow will continue to produce an area of light
showers/virga extending from south central MT into northwest and
far north central ND. Associated surface low pressure from central
North Dakota into southwest South Dakota will push slowly east.
Strong southerly winds over the James River Valley, ahead of the
surface trough, will diminish late this afternoon and evening.
Capping over this same region is expected to inhibit any
afternoon/evening convection despite a moderately unstable
atmosphere.

Moderate to strong 700-500mb frontogenesis develops tonight over
a good portion of central and northwest ND north of the surface
trough. Although synoptic scale forcing is not strong, it does
persist over this same area. Global models have been persistent
the last couple of runs in developing a band of light
precipitation over western and central ND late tonight into friday
morning, which is handled well with the current forecast.

Continued surface and mid level forcing along the surface front,
combined with upper level divergence over the region, will
support an area of thunderstorms Friday, but most likely just to
the south and east of the forecast area. Although we will need to
monitor the southern James river valley for possible thunderstorm
activity in case there is some north and/or westward shift to the
surface boundary. Most of the CWA will be cooler on Friday (50s
and 60s) but the southern James River Valley could see some
readings near 80.


.LONG TERM...(Friday night through Thursday)
Issued at 307 PM CDT Thu Sep 21 2017

Cool and showery weather remains through the upcoming weekend and
into early next week. Highs mainly in the 50s and lows generally
in the upper 30s to mid 40s. Substantial cloud cover should
inhibit any widespread frost, but will certainly have to monitor
the western half of ND in case we would happen to clear out more
than expected.

Precipitation chance wane as we head into the middle of next week
but we remain at or below seasonable normals.

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 307 PM CDT Thu Sep 21 2017

A cold front will move through central ND this afternoon and
evening. Strong southerly winds ahead of the front will shift
north to northwest behind the front. Mid level VFR conditions
expected behind the front tonight. MVFR ceilings will lift from
south Dakota northward into ND after 12 UTC Friday bringing a
period of MVFR ceilings to KJMS and possibly KBIS 15-18 UTC.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...TWH
LONG TERM...TWH
AVIATION...TWH