Truesdale, Iowa Weather Forecast Discussion

378
FXUS63 KFSD 191738
AFDFSD
Area Forecast Discussion
National Weather Service Sioux Falls SD
1238 PM CDT Fri Sep 19 2025
.KEY MESSAGES...
- Scattered showers and very isolated thunderstorms will
  continue into Saturday, with the greatest coverage on Friday.
  A very low chance of a weak funnel is possible Friday
  afternoon.
- Temperatures warm slightly Sunday, bringing a risk for a few
  late day and nighttime thunderstorms. Severe weather risks
  remain low.
- Near normal temperatures are likely most of next week, with a
  rather uncertain precipitation forecast through the week.
&&
.DISCUSSION...
Issued at 209 AM CDT Fri Sep 19 2025
THIS MORNING: A large upper trough continues to rotate through
the Dakotas early this morning. An extended mid-lvl trough
pivoting northward this morning will continue to produce an area
of light rain thanks to persistent dPVA. This more extensive
area of rain will likely stay east of I-29. A second area of
even lighter showers to sprinkles is tied to a 925:850 mb
trough centered west of the James River but pivoting east
northeast. Areas of fog are also expected within a narrow
corridor near or east of this low-lvl trough. Visibilities may
drop below 1/2 mile along portions of Highway 14 into the
daylight hours.
TODAY:  The upper low wobbles and sinks southeast through the day on
Friday, keeping a fairly persistent light to moderate shower in the
Tri-State area through the day. While severe storms are not
expected, a cluster of CAMs all indicate some increased NST and
stretching parameters extending along a northeastward pivoting
surface boundary by early to mid afternoon. So should a small amount
of instability build, a few funnels may form within the redeveloping
showers.  The area most likely to be impacted would be along and
northeast of a Huron to Madison to Spencer line.
TONIGHT: Quite a bit of cloud cover is likely to linger through the
night.  After a cool day in the 60s, a gradual diminishing of echoes
should begin by the evening with a few lingering sprinkles/showers
tied directly to the upper low core.
SATURDAY: The aforementioned upper low pivots east of the area
towards Wisconsin on Saturday.  In it`s wake, very light flow and
lingering moisture, combined with some self-destructive CU, could
lead to a few afternoon sprinkles.  High temperatures warm slightly
from Friday, but remain near to slightly below normal.
SUNDAY: A broad upper trough remains in place over the Northern
United States into the end of the weekend. A secondary wave within
the trough sinks through the Plains on Sunday.  Warm advection ahead
of this wave could lead to a few Sunday morning showers and
thunderstorms, but lift overall weakens in the afternoon as
temperatures rise.  That said, tall thin CAPE profiles, subtle mid-
lvl wedge of dry air, and very weak inhibition could lead to a few
windy showers and thunderstorms by the evening.  This risk could
continue into the overnight hours.
NEXT WEEK: Confidence remains quite low in the forecast for next
week, given a multitude of mid-lvl waves likely crossing through the
Plains and a generally weak flow pattern.  The primary agreement in
model solutions is that another piece of energy dips into the
Central and Southern Plains and becomes mostly cutoff from the weak
flow.  However that`s about where the agreement ends as large scale
differences in timing and location of the upper low continue.  All
that said, confidence rises slightly in the projection of near
normal temperatures through the week. Regarding precipitation
chances, there is really minimal agreement in any guidance.
Ensembles spread PoPs across nearly the entire central United States
by mid-week. At this time, can`t see any strong evidence to deviate
from the NBM guidance.
&&
.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1237 PM CDT Fri Sep 19 2025
Latest satellite imagery shows low level stratus blanketing the vast
majority of the area. The stratus is sitting at MVFR/IFR levels
while visibilities remain largely VFR. Light rain is falling beneath
the stratus, most notably across portions of southwest Minnesota and
parts of northwest Iowa. With low pressure just north of the area,
think that the MVFR/IFR stratus will continue to sit over the area
for the rest of today. Trends will be monitored though. Ceilings may
lower back to LIFR levels tonight but confidence is not high enough
to include in a TAF at this time. Patchy fog is also possible
beneath the stratus as well, though again, confidence is not high
enough to include in a TAF at this time. The stratus and light to
very light rain showers will persist through the overnight hours
before ceilings lift back to MVFR levels to end the period. &&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.
&&
$$
DISCUSSION...Dux
AVIATION...Meyers

NWS FSD Office Area Forecast Discussion