191
FXUS63 KFSD 250818
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
318 AM CDT Sat May 25 2024

.KEY MESSAGES...

- Seasonal temperatures expected for the holiday weekend with
periodic chances for showers and thunderstorms. The overall severe
weather threat remains low.

&&

.DISCUSSION...
Issued at 318 AM CDT Sat May 25 2024

he leading edge of a weak piece of mid level energy will move into
the area this morning but not bring much with it. For the most part
the atmosphere is very dry below 700 mb so the only thing available
to produce precipitation is moisture in the dendritic layer, which
is very high, and any instability in the EML, which is pretty weak.
So, for the most part just expecting some sprinkles with a small
chance for a hundredth or two if some slightly higher instability
comes around. This potential will mainly be this morning into early
afternoon and north of I-90. By late this afternoon and tonight
showers and a few thunderstorms will be possible but right now
instability looks pretty weak. Both the GEFS and EC Ensemble showing
about 20% chance or lower of 500 J/kg CAPE near the Missouri River
with almost no chance for 1000 J/kg CAPE anywhere. The slightly
better chance for the higher CAPE values will be central SD late this
afternoon then down the Missouri River into northeast NE and
northwest IA later tonight. Not too dissimilar to Thursday night,
just less instability and a weaker wave. Suspect with the decent
little wave moving through NE tonight some showers will develop with
the best chance for the better ingredients for storms and very
isolated severe weather to come together in northeast NE and
northwest IA from about 10 pm to 5 am. Once again, chances look
pretty low but a couple of stronger updrafts not out of the
question. One thing to watch out for is with a pretty dry sub cloud
layer there could be some wind that sneaks north out of the
potentially stronger convection in NE.

Otherwise for today it will be warmer but once again windy. Not as
windy as Friday but still some stronger winds this morning into early
afternoon. Suspect some gusts of 35 to 40 mph.

Sunday should see roughly two areas with potential for showers and
thunderstorms. The first will be the wave moving through NE which
should bring some forcing and moisture north towards northeast NE
into northwest IA, especially in the afternoon and evening. Overall
the instability is pretty weak so right now not concerned about
severe weather. The other area will be a wave moving through
southern ND which may spark some showers or isolated thunderstorms
in central SD late afternoon and evening then mainly north of I-90
during the evening into Sunday night. This area also appears to pose
no severe weather threat.

Once this wave passes on Sunday night a cooler pattern with below
normal temperatures is expected Monday and Tuesday. A wave passes by
through MN on Memorial Day and could allow for a few showers and
isolated thunderstorms mainly east of the James River.

Upper level ridging builds into the area Wednesday and Thursday
which should bring back normal to above normal temperatures.
Wednesday should be dry, but with troughiness developing over the
Northern Rockies on Wednesday night Thursday into Friday will likely
see the next chances for showers and thunderstorms.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1024 PM CDT Fri May 24 2024

Light southerly winds overnight, increasing late Saturday
morning and gusting around 20kts through the afternoon and early
evening. There will be a small probability (20-30%) of showers
or sprinkles north of Interstate 90 on Saturday afternoon, then
increasing chances for showers and isolated thunderstorms on
Saturday night.

&&

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

&&

$$

DISCUSSION...08
AVIATION...JM