392 
FXUS63 KBIS 011412
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
912 AM CDT Sun Sep 1 2019

.UPDATE...
Issued at 911 AM CDT Sun Sep 1 2019

Still widespread fog in southwest North Dakota, with a low stratus
deck across much of the central part of the state. Expecting both
of these to lift within the next few hours, leading to a rather
nice day before the chance of showers and thunderstorms returns
this evening. No major updates to the forecast at this time.

UPDATE Issued at 612 AM CDT Sun Sep 1 2019

Only minor adjustments were made to the forecast this morning to
better line up with near-term trends. Expanded fog/cloud cover a
bit in time and area for this morning. 

&&

.SHORT TERM...(Today and tonight)
Issued at 316 AM CDT Sun Sep 1 2019

Moisture continues to stream northward and pool ahead of a weak
surface trough currently located across far northwest North
Dakota. This is leading to widespread low stratus and fog across
much of southern and central North Dakota. The trough will swing
through and winds shift by mid morning which should clear out the
stratus and fog. 

Upslope flow will once again be present over the area by this
evening as the deeper upper level low and associated lee trough
develop and push into the area. Showers and thunderstorms may
develop later this evening across western North Dakota as a warm
front advances northeastward. Initial storms should be elevated
but could still produce some hail and gusty winds with ample shear
present over the area. The main thunderstorm show and potential
severe weather is expected later on Monday. 

.LONG TERM...(Monday through Saturday)
Issued at 316 AM CDT Sun Sep 1 2019

As the mid-level wave approaches and low-level cyclogenesis 
commences warm, moist advection will kick into high gear Monday. 
General consensus is that elevated storms will be ongoing across 
western North Dakota during the first half of the day Monday. A 
warm front should stretch from northern North Dakota southeastward
to northern Wisconsin. This will be the main focus for storm 
development throughout the day. 

Models are fairly consistent in developing scattered to widespread
storms Monday late afternoon/evening along an axis from 
northeastern North Dakota southeastward along the eastern edge of
a stout EML. The bulk of the storms should be elevated, but the
threat for severe storms still exists as steep lapse rates aloft 
could result in a risk of hail. A surface-based storm or two 
evolving within this activity may attain a greater tornadic and 
damaging wind threat given supercellular shear profiles and 
moderate to strong instability. 

Another uncertainty regarding the severe-weather scenario is the
strength/warmth of the EML and associated mid-level inhibition
across the open warm sector. A strongly sheared, strongly 
unstable environment supporting supercellular development, very 
large hail, and a few tornadoes will be present Monday
afternoon/evening, but the question is whether or not the cap will
prevent surface-based storms from developing and tapping into that
extreme environment.

Dry and cooler conditions are expected on Tuesday behind the 
exiting northern stream wave, then another wave tracks through the
mean ridge bring small shower/thunderstorm chances Wedneday 
through Friday. Temperatures remain cool.

&&

.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 612 AM CDT Sun Sep 1 2019

MVFR/IFR in stratus and fog across southwest and central North
Dakota this morning. Conditions will improve later this morning.
Showers and thunderstorms will enter western North Dakota after
00z Sunday evening and spread north and east through the night. 


&&

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

$$

UPDATE...MJ
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...AJ