553
FXUS63 KFSD 101114
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
614 AM CDT Fri May 10 2024

.KEY MESSAGES...

- Warm and breezy conditions are expected on Friday, with a
  very low chance for an isolated shower over Southwest
  Minnesota or Northern Iowa in the afternoon.

- Temperatures remain above normal through the weekend, with
  highs in the 80s on Sunday combining with a front to produce
  scattered thunderstorm risks.

- Slightly cooler to start next week, with increasing rain
  chances late Tuesday into Wednesday.

&&

.DISCUSSION...
Issued at 222 AM CDT Fri May 10 2024

THIS MORNING:  The diurnal drop in temperatures has stalled as mid-
lvl clouds within a weak warm advection regime are providing some
insulation.   However, some sheltered areas in SW Minnesota and NW
Iowa may still fall into the lower 40s.

TODAY:  Mid-lvl clouds will continue to increase through the morning
hours as a surface front tracks southeast through the Tri-State
area.  This front will be pushed through the area by an upper trough
moving into the western Great Lakes.  A very low chance for a few
showers may develop in SW Minnesota into Iowa later afternoon.
Temperatures are expected to climb a few degrees warmer than on
Thursday, as 850 mb rise ahead of the upper trough.  This may likely
push temperatures into the lower to middle 70s.  The afternoon may
be quite breezy with gusts over 25 mph at times.

TONIGHT: Skies clear and winds turn light and variable overnight as
high pressure moves into the Dakotas.  This combination should
provide optimal viewing conditions for the potential northern lights
show into Saturday morning with space weather forecasts suggesting
best viewing from 03Z to 12Z Saturday.

SATURDAY:  Winds increase through the day on Saturday, turning
southwesterly in response to a mid-lvl trough crossing the Northern
Rockies.  As 850mb temperature rise towards the +11 to +14C range
during the day, this should result in widespread highs in the middle
to upper 70s.

SUNDAY:  A frontal boundary approaches the CWA on Sunday as mid-lvl
troughing crosses the Dakotas.  A fairly weak LLJ early Sunday
should lead to scattered mid-lvl clouds, and perhaps a low risk for
a few isolated showers in the morning.  However slightly higher
risks for convection will present themselves along the frontal
boundary Sunday afternoon.  Depending on the quality of the low-lvl
moisture, we may see upwards of 500-800 J/KG MLCAPE ahead of the
boundary.  Increasing synoptic lift should spark scattered showers
and a few thunderstorms into Sunday evening.  However, with
effective shear only around 10 knots, the greatest risk would be for
some high based stronger downdraft winds. Temperatures Sunday
may be dependent on mid-lvl cloud cover formation. GEFS/ECM/CMC
all indicate probabilities for temperatures over 80, with the
Canadian ensemble more bullish areawide and GEFS/ECM suggesting
high probabilities focused in the higher elevations.

MONDAY-THURSDAY: Weak cold air advection behind the upper trough
will lower temperatures slightly on Monday. Though, this cooldown
will be short-lived as ridging increases quickly on Tuesday.  The
next meaningful rain chance moves in late Tuesday through Wednesday
heights fall over the High Plains and moisture begins to return back
towards the Dakotas.  A passing cold front will provide enough lift
for scattered storms into Wednesday, though the severe weather risk
remains fairly low.  Expecting NBM PoPs to continue their slow
upwards climb over the upcoming day or two given strong signals in
GEFS/ECM probabilities of 0.1"of 70-80%.  Only reason PoPs are
currently lower is the slight mis-match in timing between the
ensemble camps. Temperatures are expected to fall back to seasonal
normals Wednesday and Thursday. &&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 546 PM CDT Thu May 9 2024

VFR conditions will prevail through the period. Cumulus will
clear out this evening with weakening winds turning westerly.
Mid to high clouds spread back in early Friday morning with
northwest winds gusting again after sunrise. Expect gusts to
peak at 25 to 30 kts Friday afternoon with a low chance of
isolated showers east of the Interstate 29 corridor.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 611 AM CDT Fri May 10 2024

VFR conditions are anticipated through the daytime hours of
Friday. A front will slide southeast by mid-day, bringing a
mid-lvl cloud deck along with it. Winds turn northwesterly and
begin to gust up to 25 to 30 mph at times.

Gridded model datasets do not really account for potential high
based CU field later this afternoon, but soundings across the
CWA suggest we may see at least a scattered 8K ft AGL cloud
field into early evening.

Winds subside after sunset with VFR conditions and clear skies
into Saturday morning.


&&

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

&&

$$

DISCUSSION...Dux
AVIATION...Dux