631
FXUS63 KBIS 071743
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1243 PM CDT Sun Jul 7 2024

.KEY MESSAGES...

- Another round of scattered showers and thunderstorms is
  expected this afternoon and early evening. Some storms may
  once again produce funnel clouds, with a weak landspout
  tornado possible.

- The daily potential for showers and storms will focus more
  over eastern North Dakota Monday and Tuesday, with coverage
  becoming more isolated.

- A warming trend is expected this week, with widespread highs
  in the 90s likely on Friday.

&&

.UPDATE...
Issued at 1243 PM CDT Sun Jul 7 2024

At 1230 PM CDT, a lone batch of showers with an embedded
thunderstorm was crossing from western Sioux and eastern Adams
Counties into South Dakota. Meanwhile, midday satellite shows
increasing cumulus along and south of Interstate 94 from eastern
Sioux County through the southern James River Valley, where
radar returns are just now beginning to increase. Current SPC
mesoanalysis shows the non-supercell tornado parameter in
LaMoure and Dickey Counties ranges from 1 to as high as 3, so
will be on the lookout for funnel clouds reports once again.

UPDATE
Issued at 849 AM CDT Sun Jul 7 2024

Patchy fog and low ceilings have developed over Foster and
eastern Stutsman Counties. Conditions are likely to improve by
around 10 AM.

For the rest of the morning, shower activity will likely remain
confined to southwest parts of the state, where an ongoing batch
of southward moving showers was crossing Interstate 94 between
Dickinson and New Salem as of 845 AM CDT. Very infrequent
lightning has been observed on the northeast side of these
showers, and do not expect any significant uptick in lightning
through the morning.

UPDATE
Issued at 600 AM CDT Sun Jul 7 2024

Two distinct circulation centers are evident via satellite
within the large scale trough over the region. Departing S/WV
centered over northern Minnesota and another embedded wave over
portions of southwest ND/northwest SD. In addition, there is
another more subtle impulse dropping south across western North
Dakota, resulting in elevated cloud cover there along with an
area of scattered showers and isolated thunderstorms advancing
south with the impulse. Also scattered showers continue over my
southeast, more associated with the S/WV to our east. For this
update, modified POPs and sky cover based on latest imagery and
trends.

&&

.DISCUSSION...
Issued at 355 AM CDT Sun Jul 7 2024

Currently, quasi-stationary long wave trough remains over the
region early this morning, with strong ridging over the west
coast. Within the trough, multiple embedded mid level impulses
continue to rotate through, contributing to scattered showers
and a few isolated thunderstorms. A more defined impulse
developing south across western ND results in a decent coverage
of showers and at times a few thunderstorms. This activity
should continue south across my west now through sunrise. Will
also maintain isolated mention elsewhere given the unsettled
atmosphere in place this morning.

For today, expect another day of scattered showers and
thunderstorms, though we start to see the better coverage of
precipitation more to the east as our persistent trough starts
to develop farther to the east, anchored more over the Western
Great Lakes/eastern Dakotas vs. centered over the central
Dakotas. Mean flow aloft will be weak today across the east, so
as we saw yesterday, there is some potential for a few heavy
rainers with expected slow moving convection. In addition, the
non-supercell Tor parameter (NST) is also similar to Saturday
when we received multiple funnel cloud reports and one
confirmed landspout tornado, so wouldn`t be surprised to see
another day of this today during the daytime hours. Showers and
isolated storms will continue into this evening, before
diminishing later tonight as sfc high pressure builds into the
region and flow aloft becomes more north/northwesterly.

The aforementioned strong upper level ridge over the west coast
will develop farther inland into the Intermountain West Monday
into Tuesday, maintaining flow aloft over the Northern Plains
out of the north/northwest. NBM has maintained low POPs over my
far east both days, and can`t argue with this as any wave
within the flow could fire off diurnally driven convection. Most
of western and central North Dakota will remain dry however.

Temperatures are still favored to slowly warm through next
week, approaching seasonal normal values (low/mid 80s) by the
middle of the week. Upper ridge broadens and expands across the
Rockies later in the week, when temperatures are favored to be
well above normal, with highs Thursday-Saturday forecast in the
mid/upper 80s to mid 90s.

While we should be mainly dry after early next week, there is
increasing potential for thunderstorms next weekend when the
ridge flattens over the Northern Plains and when models depict
favorable upper level jet dynamics aloft as a S/WV trough
swings east across Canada. NBM put in slight chance POPs Fri-
Sun, along with the CSU machine learning indicating some low
severe probabilities during that timeframe. Thus, something to
keep an eye on.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1243 PM CDT Sun Jul 7 2024

Scattered showers and thunderstorms are likely to develop once again
this afternoon and evening. The highest confidence in coverage of
showers and storms is from around KBIS to KJMS, where VCTS has been
included. Elsewhere, coverage is likely to be more widely
scattered to isolated, and far western North Dakota could
remain completely dry. Any heavier shower or storm could produce
brief periods of MVFR to IFR visibility. Otherwise, VFR
conditions are likely through the forecast period. Some patchy
fog could develop late tonight into Monday morning, but
confidence on exact location is low. Northwest winds around
10-15 kts this afternoon will become light after sunset.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

UPDATE...Hollan
DISCUSSION...NH
AVIATION...Hollan