Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 220327
AFDFSD

AREA FORECAST DISCUSSION
National Weather Service Sioux Falls SD
1027 PM CDT Mon Oct 21 2019

.SHORT TERM...(This Evening through Tuesday)
Issued at 349 PM CDT Mon Oct 21 2019

A strong, negatively-tilted longwave trough will be the main driver
of weather over the next 36 hours. An already tight pressure
gradient will be enhanced by a shortwave that rotates through the
main trough this evening, forcing exceptionally strong winds in the
low-levels of the atmosphere, with a focus over the Coteau des
Prairies in eastern SD and southwestern MN. Widespread light rain
will aid in transporting momentum down to the surface, and
northwesterly wind gusts in the 50 to 60 mph range looks likely this
evening and during the early overnight hours. A High Wind Warning
covers the most likely locations and timeframe for these gusts, with
a Wind Advisory running well into Tuesday for continued breezy
conditions.

Light precipitation will end and low cloud decks will thin after
midnight. Temperatures on Tuesday will be about 10 degrees below
average, and morning wind chills will be in the 20s due to continued
breezy weather with gusts in the 40 mph range. It`s not until the
evening that the pressure gradient relaxes, allowing winds to
become light after sunset.

.LONG TERM...(Tuesday Night through Monday)
Issued at 349 PM CDT Mon Oct 21 2019

A weak shortwave moving through northwesterly jet aloft will
bring another period of precipitation on Wednesday morning. Lift
does not look overly impressive at this time, with limited
moisture in the column; however, cold temperatures around sunrise
will mean that a dusting of light snow is possible for locations
north of I-90, such as Brookings, SD and Slayton, MN.
Accumulations currently look to be under half an inch, but
continue to keep an eye on this portion of the forecast, as these
small-wavelength, banded- precipitation features are notoriously
difficult to forecast. After sunrise, temperatures warm to above
freezing, minimizing the impact of any light snow.

The rest of the work week will be characterized by dry weather, cooler
than normal conditions, and light winds. Dry northwesterly flow
aloft and subtle ridging reign. Afternoon highs run in the mid 40s
to low 50s. Saturday looks to be the warmest day of the next
seven, as a surface high to the southeast and troughing over the
Western CONUS help force southerly surface winds. A dry cold front
on Sunday brings a return of 40s for highs.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1023 PM CDT Mon Oct 21 2019

Northwest winds continue to gust between 35-45 kts with a few
gusts toward 50 kts observed thus far. These winds will continue
thru the overnight hours, only slowly diminishing thru the daytime
hours Tuesday. By late afternoon and evening Tuesday, winds are
expected to have significantly decreased. Hit or miss showers
will continue, mainly over SW MN, for the next few hours with
clearing skies already nearing KHON from the west, with MVFR
ceilings elsewhere.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...High Wind Warning until 4 AM CDT Tuesday for SDZ039-040-054>056-
     061-062-066-067-070-071.

     Wind Advisory until 4 PM CDT Tuesday for SDZ038-053-059-060-065-
     068-069.

     Wind Advisory from 4 AM to 4 PM CDT Tuesday for SDZ039-040-
     054>056-061-062-066-067-070-071.

     Wind Advisory until 4 AM CDT Tuesday for SDZ050-052-057-058-063-
     064.

MN...High Wind Warning until 4 AM CDT Tuesday for MNZ071-072-080-081-
     089-090-097-098.

     Wind Advisory from 4 AM to 4 PM CDT Tuesday for MNZ071-072-080-
     081-089-090-097-098.

IA...High Wind Warning until 4 AM CDT Tuesday for IAZ001>003-012>014-
     020>022-031-032.

     Wind Advisory from 4 AM to 4 PM CDT Tuesday for IAZ001>003-
     012>014-020>022-031-032.

NE...High Wind Warning until 4 AM CDT Tuesday for NEZ013-014.

     Wind Advisory from 4 AM to 4 PM CDT Tuesday for NEZ013-014.

&&

$$

SHORT TERM...VandenBoogart
LONG TERM...VandenBoogart
AVIATION...Kalin


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