152
FXUS63 KFSD 070330
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
1030 PM CDT Sat Jul 6 2024

.KEY MESSAGES...

- Increasing coverage of showers and thunderstorms through this
  afternoon to mid evening, diminishing again by midnight
  tonight. A few strong to severe storms are possible with large
  hail and damaging winds the primary threats.

- Patchy fog again possible tonight-early Sunday. Widespread
  dense fog is not expected, but isolated visibility below a
  mile is possible.

- Unsettled weather continues early next week with spotty
  afternoon to early evening showers/storms Sunday-Wednesday.
  Severe weather is not expected.

- Cooler than normal temperatures for early July through the
  early part of next week, but trending closer to normal by the
  end of the week.

&&

.DISCUSSION...
Issued at 208 PM CDT Sat Jul 6 2024

Afternoon/Evening: Focus will be on the wave currently evident on WV
imagery diving through the central Dakotas as of early afternoon.
This will be entering an environment characterized by MLCAPE values
of up to 1000-1500 J/kg. While deep layer shear is weighted south of
I-90 away from the better dynamics, up to 30-35 kts of EBWD is
progged north of I-90 and may allow for some organization of
thunderstorms. Additionally, fairly straight hodographs may allow
for splitting cells in any of this more organized activity. Large
hail up to ping pong ball size appears to be the primary risk with
wind gusts up to 60-65 mph possible with an occasional sounding
showing a modest dry subcloud layer and DCAPE values approaching
1000 J/kg. While an extremely low potential, a muddled low level
wind profile can at times lend to a low end landspout potential
with non-supercell parameter between 0.5-2 through the deeper
convergence zones.

In terms of rainfall, PWATS around 1.25 and 850 mb dewpoints
exceeding 10C will likely allow for efficient rain rates in any
healthier thunderstorms, although activity looks progressive enough
to prevent any widespread issues. HREF PMM/LPMM do show the
potential of localized pockets to around 2-2.5 inches with most
locations less than that. While unwelcome in flood stricken areas,
don`t suspect we`ll see any significant river rises from the more
isolated amounts and instead focus for any problems will likely be
in urban and poor drainage areas.

Overnight: As has been the case the last couple of mornings, very
well could see some patchy fog in low lying areas. Have introduced
this mention into the forecast through the daybreak hours Sunday
morning.

Sunday: Another day where forecast soundings suggest the potential
for some scattered showers and thunderstorms in the afternoon and
early evening hours as the cooler upper low swings overhead. Lack of
a stronger wave likely keeps activity non-severe and less organized
than today. Will keep chance level POPs in the afternoon and early
evening hours. Temperatures again in the mid 70s to lower 80s.

Monday thru Wednesday: No real significant changes for the early to
mid work week as occasional weak waves slide down the backside of the
upper trough lending to occasional afternoon/evening shower chances.
At this time, the focus looks to be near and east of I-29.

Thursday and Friday: West coast ridging tries to build eastward and
should provide for drier conditions and warming temperatures.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1030 PM CDT Sat Jul 6 2024

Light winds overnight will result in patchy fog across the area
into early Sunday morning. Showers and thunderstorms will
develop once again on Sunday into Sunday evening. Winds will be
light west/northwesterly during the day on Sunday, becoming
nearly calm and variable on Sunday evening.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.

&&

$$

DISCUSSION...Kalin
AVIATION...JM