Area Forecast Discussion
Issued by NWS Bismarck, ND

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000
FXUS63 KBIS 190832
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
332 AM CDT Mon Sep 19 2016

.SHORT TERM...(Today and tonight)
Issued at 332 AM CDT Mon Sep 19 2016

For the near term...through 12z/0700 CDT Monday, isolated to
scattered showers far south central/southern James River Valley will
continue to shift east. This is associated with forcing aided by
the right entrance region of a jet streak along with a weak
shortwave scooting across northern SD.

For today, height rises occur in response to a deepening upper
level low per water vapor imagery just off the coast of Vancouver
island. Broad ridging and associated subsidence dominates resulting
in plenty of sunshine and somewhat breezy westerly winds this
afternoon/15 to 25 mph most areas. The exception will be across
the north where winds will be strongest (25 to 35mph) closest to
the stronger winds aloft/jet streak as it migrates just north of
the border this evening. Highs will mostly be in the lower 70s,
with some upper 60s across the north and northwest.

For tonight, weak mid level frontogenetical forcing develops in
southeast MT, then shifts across southern ND through 12z Tuesday.
The NAM/GFS/ECMWF do develop patches of light precipitation with
this feature. This may prompt a few showers and have blended the
above models to produce a slight chance southwest into portions of
south central. Elsewhere it remains dry with lows but not much
signal in the current gridded data as of now, so will continue
with mainly a dry forecast. Lows tonight mostly in the 40s except
around 50 south where we expect a bit more clouds.

.LONG TERM...(Tuesday through Sunday)
Issued at 332 AM CDT Mon Sep 19 2016

A wetter period evolves Thursday into Saturday. However,overall
placement and amounts of highest rainfall totals continue to
change per each GFS/ECMWF model run. There has been a decent
signal to place northwestern ND as the most favored area for the
highest rainfall amounts during the Thursday through Saturday
timeframe. This is advertised in the Ensemble Situational Awareness
Table and GEFS QPF M-Climate percentile - which suggests northwest
ND resides within the 99th percentile to the MAX regime area
during the Thursday night - Saturday timeframe. This signals a
rare event if everything holds together. However as noted in WPC`s
Extended Forecast Discussion, several possibilities exist with
this upcoming system, but what also remains just as likely is for
none of the possibilities to occur. Hence, as of now, the
placement of heaviest rainfall should be viewed just as a possible
potential at this time, and not much more than that until we get
closer to the event. The next few days will help focus on a best
solution.

The upper low mentioned above which is now west of Vancouver
Island digs south into the intermountain west Thursday/Friday,
then ejects into northeast Montana Saturday and across northern ND
Sunday. In doing so, for the Tuesday night into Wednesday period,
a couple shortwaves will shift through the broad ridge for some
mention of showers during this time period. Upper level ridging
briefly sharpens Thursday prior to the upper low ejecting out of
the intermountain west. The ridge should hold off any significant
chances of precipitation until Thursday afternoon into Thursday
night west, then spreading into central ND Friday afternoon. This
will likely change somewhat over the next few days depending on
the movement and evolution of the lows trajectory. Highs are
forecast in the 70s Tuesday, and then 60s Wednesday. This will be
followed by highs mostly in the upper 50s to lower 60s Thursday
through Sunday.

&&

.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 332 AM CDT Mon Sep 19 2016

Vfr cigs/vsbys this Taf period. Expect a period of sct/bkn mid
level clouds from KDIK/KBIS/KJMS through 14z Monday, then SKC
through the remainder of the period.

&&

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

$$

SHORT TERM...KS
LONG TERM...KS
AVIATION...KS



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