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FXUS63 KBIS 221442
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
942 AM CDT Sat Jul 22 2017

.UPDATE...
Issued at 942 AM CDT Sat Jul 22 2017

Current temp obs running a tad cooler than forecast trend. Also
dewpoints in the west not lowering as quickly as forecast. However,
temps rising and seeing dry air in Montana with dewpoints in the 30s
and upper 20s. Thus adjusted recent hourly observations and blended
with current afternoon forecast. Forecast appears on track for
today, including current red flag warning in the southwest and far
south central.

UPDATE Issued at 646 AM CDT Sat Jul 22 2017

Temperatures were running a little cooler than forecast, so
adjustments were made to account for that. Otherwise, forecast
remains on track. With the sun now up, can see smoke well off to
the west/southwest. Forecast grids already have smoke mentioned in
that area, so no changes made with this either.

&&

.SHORT TERM...(Today and tonight)
Issued at 400 AM CDT Sat Jul 22 2017

Highlight today will be fire weather. Have issued a Red Flag Warning
for southwest and portions of south central ND this afternoon.
See the fire weather discussion below for further details.

Unrelated to the above will be patchy smoke today across mainly
southwestern and south central North Dakota from ongoing fires
in Montana, and also extending into the southern Canadian
provinces.

Latest water vapor imagery shows a westerly to northwest upper flow
into North Dakota early this morning. This is the result of an
upper low/associated trough located over southeast Saskatchewan
and southwest Manitoba, in combination with broad ridging over
the Northern Rockies. Expect plenty of sunshine today, dry, not as
hot, but windy this afternoon with northwest winds between 20 and
30 mph. Highs will range from the upper 70s north, to upper 80s
south. For tonight, clear and tranquil with lows in the mid 50s.

.LONG TERM...(Sunday through Friday)
Issued at 400 AM CDT Sat Jul 22 2017

The Northern Rockies ridge will amplify and progress east Sunday,
shifting through central ND evening. This will result in another
sunny day Sunday with lighter winds, less than 10 mph. Continued
warm with highs in the upper 70s east, to 90 degrees west.

As the ridge shifts east Sunday evening, low level southerly winds
increase in response to a developing surface low pressure in
eastern Montana. This surface low is being supported by a closed
mid/upper level low moving east from central Alberta Sunday night,
into central Manitoba by Tuesday. In doing so, the surface low
pressure in eastern Montana will also move east, moving along an
advancing cold front, which is forecast to slide into western ND
Monday afternoon, and exit the James River Valley late Monday night.
This will set up a round of showers/thunderstorms Monday afternoon
into Monday night. SPC has central ND within a Marginal Risk for
Severe Thunderstorms. Expectations of isolated severe thunderstorms
forming along the cold front during the afternoon with ample
instability which will continue into the evening hours. Will
monitor this over the next couple of days. Highs will return into
the lower 90s Monday afternoon across central and southern ND
ahead of the cold front.

By Tuesday, the system supporting the cold front from Monday/Monday
night will have shifted far enough east, allowing a west to
northwesterly flow of dry air and calmer conditions Tuesday, and
most likely continuing through Wednesday. High temperatures will
be in the upper 70s north to lower/middle 80s south both days.
The next shortwave trough is slated for Thursday and Friday with
warmer temperatures and some potential for showers/thunderstorms,
although the GFS and ECMWF differ in their solutions by this time.

$$

.AVIATION...(For the 12Z TAFS through 12Z Sunday)
Issued at 646 AM CDT Sat Jul 22 2017

Vfr cigs/vsbys this Taf period with generally SKC condition.
Northwest winds between 20kt and 30kt expected today, becoming light
after sunset. Smoke from wildfires in Montana is visible to the
west/southwest. Currently not expecting smoke to reduce
visibilities at the surface, but will continue to monitor.

$$

.FIRE WEATHER...
Issued at 400 AM CDT Sat Jul 22 2017

With high temperatures in the upper 80s, northwest winds between
20 and 30 mph this afternoon, combined with minimum relative
humidities as low as 15 percent and very dry fuels, expect critical
fire weather conditions over southwest and portions of south central
North Dakota this afternoon and early evening. Thus a Red Flag Warning
has been issued from noon CDT Saturday until 9PM CDT Saturday.

&&

.AVIATION...(For the 12Z TAFS through 12Z Sunday)
Issued at 646 AM CDT Sat Jul 22 2017

Vfr cigs/vsbys this Taf period with generally SKC condition.
Northwest winds between 20kt and 30kt expected today, becoming light
after sunset. Smoke from wildfires in Montana is visible to the
west/southwest. Currently not expecting smoke to reduce
visibilities at the surface, but will continue to monitor.

$$

.FIRE WEATHER...
Issued at 400 AM CDT Sat Jul 22 2017

With high temperatures in the upper 80s, northwest winds between
20 and 30 mph this afternoon, combined with minimum relative
humidities as low as 15 percent and very dry fuels, expect critical
fire weather conditions over southwest and portions of south central
North Dakota this afternoon and early evening. Thus a Red Flag Warning
has been issued from noon CDT Saturday until 9PM CDT Saturday.


&&

.FIRE WEATHER...
Issued at 400 AM CDT Sat Jul 22 2017

With high temperatures in the upper 80s, northwest winds between
20 and 30 mph this afternoon, combined with minimum relative
humidities as low as 15 percent and very dry fuels, expect critical
fire weather conditions over southwest and portions of south central
North Dakota this afternoon and early evening. Thus a Red Flag Warning
has been issued from noon CDT Saturday until 9PM CDT Saturday.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 9 PM CDT /8 PM MDT/ this evening for
NDZ031>033-040>045.

&&

$$

UPDATE...JV
SHORT TERM...KS
LONG TERM...KS
AVIATION...KS/JNS
FIRE WEATHER...KS