000
FXUS63 KFSD 090843
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
343 AM CDT Tue Apr 9 2024

.KEY MESSAGES...

- A few sprinkles will be possible this afternoon. However,
  little to no accumulation is expected.

- Temperatures will continue to trend warmer heading into the
  midweek. However, more light rain chances (20%-40%) will
  return from Wednesday into Thursday with accumulations
  expected to stay below a tenth of an inch.

- The combination of mild, dry, and breezy conditions will lead
  to more elevated fire weather concerns from the midweek into
  the weekend.

- The uncertainty continues in the extended portions of the
  forecast with ensemble guidance continuing to show up between
  a 10-20 degree spread in potential highs over the weekend.

&&

.DISCUSSION...
Issued at 335 AM CDT Tue Apr 9 2024

The Short Term (Today & Tonight):

A beautiful day is ahead! Looking at satellite imagery, mostly mid
to high level clouds continue to stream into areas north of I-90
this morning as mid-level warm air advection (WAA) begins to settle
in aloft ahead of our next shortwave. A mixy environment coupled
with breezy westerly winds (gusts up to 25 mph) will help
temperatures make a dramatic improvement from the previous
stretch of days with highs expected to peak in the low to mid
60s for the day. However, there is a small possibility (10%-15%)
that some sprinkles could become embedded within a developing
cumulus field this afternoon as increased isentropic lift from
the incoming wave interacts with weak instability (50-150 J/kg)
across portions of the area. Nonetheless, little to no
accumulation is expected with the developing precipitation.
Otherwise, westerly winds will gradually decrease after sunset
as overnight lows decrease into the upper 30s to low 40s for the
night.

The Long Term (Wednesday-Monday)

Heading into the midweek, things become a bit more active aloft
as a weak trough begins to move across the region on Wednesday
bringing more precipitation chances (20%-40%) to the area.
Looking aloft, the consensus among guidance shows the trough
diving southeastwards from eastern Montana and northeastern
Colorado into the Dakotas during the day on Wednesday. From
here, increasing lift behind the surface cold front will
interact with about 150-350 J/kg of instability across our area
triggering the development of a few light to moderate showers
with potentially a few rumbles of thunder from Wednesday
afternoon into Thursday. However, only light accumulations are
expected with most ensemble guidance showing low confidence
(10%-20%) in a tenth of QPF. Shifting gears here, a tightening
SPG on both Wednesday and Thursday will lead to breezy to strong
northwesterly winds with gusts between 25-35 mph expected on
Wednesday and 30-40 mph gusts expected by Thursday. This
combined with mild temperatures and drier air especially on
Thursday will lead to high fire danger across areas along and
west of our River Valleys on Wednesday and very high fire
danger area-wide on Thursday.

Looking into the weekend, quiet and potentially warmer conditions
will be ahead as a broad upper-level ridge builds across the
area by Friday. Southerly to southwesterly surface flow along
with increased WAA underneath the ridging could lead to some
fairly impressive temperatures (potentially up to 80 degrees)
over the weekend. While the spread has started gradually shrink
in recent model runs, both deterministic and ensemble guidance
continue to show a 10-20 degree spread for high temperatures
over the weekend. Looking at ensemble guidance, the GEFS has
starting trending more towards the mean with the 00z run while
the GEPS continues its warm bias. On the other end of the
spectrum, the Euro continues to run at the mean or just below it
for temperatures this weekend. With this in mind, the NBM has
continued to trend warmer with the latest run, but at a slower
rate than the previous forecasts. Lastly, continued warmth along
with breezier conditions over the weekend will lead to more
elevated fire weather concerns area-wide.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1010 PM CDT Mon Apr 8 2024

Clouds will slowly decrease overnight, leading to VFR
conditions through the remainder of the TAF period. Winds will
be west/northwesterly tonight through Tuesday, with a few gusts
near 20 kts on Tuesday afternoon.

&&

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

&&

$$

DISCUSSION...Gumbs
AVIATION...JM