Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 260220

Area Forecast Discussion
National Weather Service Bismarck ND
920 PM CDT SAT JUN 25 2016

Issued at 920 PM CDT Sat Jun 25 2016

Winds (and shower activity in the north) are decreasing with the
onset of boundary layer cooling, which is leading to at least a
partial decoupling of the well-mixed layer from the surface. We
thus let the wind advisory expire. The rest of the forecast is on
track and all we did with this update was blend observations into
hourly forecast fields through late evening.

UPDATE Issued at 632 PM CDT Sat Jun 25 2016

We are maintaining the wind advisory as-is with this update given
sustained speeds and gusts which are still near or exceeding our
advisory criteria at several sites as of 23 UTC. We did nudge the
wind speeds down ever-so-slightly after dark using bias-corrected
short range consensus and the 21 UTC LAMP guidance since forecast
soundings from the RAP and HRRR suggest the boundary layer should
at least attempt to partially decouple overnight. Winds will stay
strongest (but lower than this afternoon/evening) in the northern
parts of the area where the surface pressure gradient will remain
strongest in closer proximity to the low over Canada. Otherwise,
we expect the showers and isolated storms in northwest and north
central ND as of 23 UTC to diminish with sunset as well once the
boundary layer begins cooling. Finally, note that we did decide
to lower temperatures a few degrees F in southwest ND with this
update given the magnitude of drying observed this afternoon and
slightly lower wind speeds now expected there overnight.


.SHORT TERM...(This evening through Sunday)

Issued at 255 PM CDT Sat Jun 25 2016

Main forecast highlights in the short term period will be gusty
winds area wide and chances for showers/t-storms north today.

Currently, winds increasing as Bufkit indicated earlier this
morning with several sites gusting in excess of 40 mph as of 19Z.
Expect this trend to continue east this afternoon/early evening as
the top of the mixing layer increases allowing stronger winds
aloft to mix down. Dewpoints in the 30s southwest and expanding
into the south central as mixing increases. Will maintain the wind
advisory as is with this forecast issuance. Showers associated
with the mid level low over far northwest North Dakota will
continue to expand east from northwestern ND into the north
central and eventually my northeast for the rest of this afternoon
through mid evening. Saw one cloud to ground lightning strike in
southern SK, so will maintain isolated thunder mention.

Breezy conditions continue tonight especially north near the mid
level low. Thus despite the low dewpoints overnight lows should
remain mainly in the 50s with a persistent mixing wind in place.

For Sunday, wrap around moisture and some mid level forcing in the
wake of the low will see another round of diurnally driven showers
mainly across the north during daylight hours. Models indicating
little if any CAPE so removed thunder and just went with showers.
Will want to look at model data close this evening and during the
overnight for possible wind headlines again Sunday. 12Z Bufkit
analysis again indicates 35-40kts available within the mixed
layer, but perhaps not as widespread as today.

.LONG TERM...(Monday through Saturday)

Issued at 255 PM CDT Sat Jun 25 2016

Broad ridging across the western CONUS will be maintained
throughout the long term period, Monday through next Saturday,
with surface high pressure over the Northern Plains region for
much of next week.

Very pleasant work week ahead with forecast daytime highs in the
70s to mid 80s, lows in the 50s, and generally low humidity. Dry
weather Monday followed by daily chances for showers and
thunderstorms thereafter for the remainder of the period. Any
large scale forcing mechanisms will mainly be associated with
embedded s/wv impulses in northwest flow aloft tracking southeast
across the region.


.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 920 PM CDT Sat Jun 25 2016

VFR conditions will prevail through Sunday afternoon, but low VFR
ceilings are likely from KISN to KMOT late tonight and Sunday. We
expect west winds to stay elevated at 15 to 20 kt overnight,
mainly from KISN to KMOT and KJMS. Winds will turn more northwest
and increase again Sunday with daytime gusts to 30 kt. A few
showers may redevelop in northern areas on Sunday, too.


.BIS Watches/Warnings/Advisories...


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