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000
FXUS63 KFSD 182238
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
538 PM CDT Thu Apr 18 2024

.KEY MESSAGES...

- Strong northwesterly winds continue through sunset today, with
  gusts at times around 40 mph. Strong winds return again Friday
  afternoon with peak mixing.

- Below average temperatures expected into the weekend. Lows
  through Saturday night fall near to below freezing. A Freeze
  Warning has been issued for portions of the area where
  vegetation is the most susceptible tonight. Additional
  headlines may be needed in the coming days.

- Moderate to high (40-70+%) chances for rain return to start
  next week. With some minor uncertainty in track, chances and
  amounts will fluctuate over the next few days.

&&

.DISCUSSION...
Issued at 344 PM CDT Thu Apr 18 2024

REST OF TODAY AND TONIGHT: More efficient mixing has allowed for
stronger northwesterly winds across the area, which will continue
through this evening. Sustained winds around 20-30 mph are being
observed, along with gusts around 40 mph. A couple of gusts to 45
mph were observed earlier this afternoon, but have been isolated and
sporadic enough to forgo any wind headlines. Mixing down the cooler
air in addition to the widespread diurnally driven cumulus clouds
are keeping temperatures in the mid 40s to lower 50s. Winds and
cumulus clouds are expected to diminish after sunset.

CAA and northwesterly flow continue tonight, with could lead to some
breezier winds overnight. Temperatures overnight into early Friday
fall into the upper 20s and lower 30s. A Freeze Warning has been
issued for areas south and east of a Yankton county, SD to Lincoln
county, MN line where the vegetation is most susceptible to these
temperatures. However, those with sensitive vegetation even outside
of this headline should take precautions to prevent damage due to
the cold temperatures. Pondered a Freeze Advisory for portions of the
area; however, given the potential for breezier winds and the
anticipated temperatures think that a Freeze Warning fits the
potential best.

TOMORROW AND SATURDAY: Similar set up for Friday and Saturday with
upper low tracking east across southern Canada, keeping us in a west
to northwest flow regime. CAA prevails, with highs again in the mid
40s to lower 50s. Based on today`s trends, did lower highs a degree
or two, especially with stronger CAA overhead early in the day.
Northwesterly winds increase quickly late morning, with sustained
winds 20-30 mph and gusts to 40 mph. Raised winds from the previous
forecast based on the mixing from today. Diurnal cumulus is likely
as well, but with extremely dry subcloud layer, kept the forecast
dry. If there were to be any sprinkles, would expect them along the
Hwy 14 corridor into southwestern MN with slightly deeper
instability. Cumulus and winds will again taper off after sunset,
but winds will remain breezy. Lows Friday night/Saturday morning
fall into the mid and upper 20s, with the entire forecast area
likely (>60%) chance of lows less than 32 degrees. Again, a headline
will likely be needed for portions of the area, especially where
growing season has begun.

Surface high slides overhead Saturday,  but otherwise another
similar day to today and Friday. Breezy to windy with highs in the
upper 40s to lower 50s. Lows again near/below freezing with
potential headlines needed, although winds again may be a spoilsport
for frost potential (leading to either freeze conditions or
nothing).

If you have sensitive or susceptible vegetation, take precautions
through the weekend to prevent damage with the cold nighttime
temperatures.

SUNDAY ONWARD: Upper ridge builds to the west during the second half
of the weekend onward, with south/southwest flow returning. Warmer
temperatures return, with highs in the upper 50s and 60s, near
normal for mid/late April. Quick moving short wave dives through the
pattern Sunday, but with a lack of moisture, forecast stays dry.
Next wave and surface low pressure move into the northern/central
Plains Monday into Monday night. Moderate to high (40-80%) chances
of rain return as the warm front lifts north (have left the NBM as
is), but there is some subtle uncertainty in the exact
timing/location and amounts. Some weak and mostly elevated
instability may be enough for a few rumbles of thunder across the
area Monday/Monday night. Low continues to track southeast early in
the week, with ridging aloft returning to the west. This ridge
slides into the Plains mid week, with near seasonal and dry
conditions expected - with the exception of isolated mid week
showers due to a weak shortwave.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 535 PM CDT Thu Apr 18 2024

VFR conditions expected through the TAF period. Gusty
northwesterly winds will drop off and become light after 02Z.
West/northwesterly then increase again on Friday, gusting 20 to
30 kts through the afternoon.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Freeze Warning from 1 AM to 8 AM CDT Friday for SDZ056-062-066-
     067-069>071.
MN...Freeze Warning from 1 AM to 8 AM CDT Friday for MNZ071-072-080-
     081-089-090-097-098.
IA...Freeze Warning from 1 AM to 8 AM CDT Friday for IAZ001>003-
     012>014-020>022-031-032.
NE...Freeze Warning from 1 AM to 8 AM CDT Friday for NEZ013-014.

&&

$$

DISCUSSION...SG
AVIATION...JM