Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 161706

Area Forecast Discussion
National Weather Service Sioux Falls SD
1206 PM CDT Sun Apr 16 2017

.SHORT TERM...(Today and Tonight)
Issued at 329 AM CDT Sun Apr 16 2017

High pressure will move across the forecast area today. A dry air
mass and brisk westerly winds will create some fire weather issues
detailed below. The strongest flow will be confined to our zones
north of I 90 this afternoon, with a mixed depth nearly to 700mb
ushering down 15 to 25 mph winds, perhaps slightly stronger in the
northern reaches of southwest MN. With the strong mixing, highs
will likely average 65 to 70 degrees across the area. Tonight,
mentioned sprinkles across our northern and western zones during
the evening hours. These areas show a modestly deep layer of
moisture between 700mb and 500mb along a very weak mid level short
wave moving southeastward on the southern side of an upper low to
our north. There is very subtle mid level convergence and warm
air advection during the evening, especially in our north. Then
these parameters pass eastward after midnight. One item to watch
for is the soundings in the sprinkle area are showing an inverted
V look. So if we do not develop a surface based inversion
immediately after sunset, there could be some locally gusty winds
under any sprinkles or virga. Otherwise with light winds late
tonight, trended toward cooler guidance readings such as MOS for

.LONG TERM...(Monday through Saturday)
Issued at 329 AM CDT Sun Apr 16 2017

Very minor modifications made to the medium and extended portions of
the forecast. We`re still looking at our next risk of rainfall to
arrive Monday night into Tuesday as a strong, but compact shortwave
moves through the Northern Plains. Models have trended slightly
drier along the advancing cold front, with the best moisture and
strongest lift focused north of the CWA. Have trended PoPs downward

Another warm day on Tuesday ahead of another progressive shortwave
moving through the Plains. Guidance continues to produce widespread
light rains by early Wednesday, although some questions linger as to
the impact of drier northeasterly flow. Nevertheless, with the track
of this open wave in a favorable spot, rain chances are still fairly
high, with most of the forecast uncertainty on forecast rainfall
amounts.  Instability continues to look meager with this system,
given 850 boundary established south of the CWA, will maintain a
very low thunderstorm risk south of I-90.

With the incoming system, temperatures will cool significantly from
Wednesday through Friday.  The coldest temperatures may fall on
Wednesday, and have lowered highs a few degrees.

Dry conditions return for the tail end of the week and through next
weekend, as a large upper trough moves through the Ozarks.
Temperatures will fall under the influence of cooler easterly flow,
remaining near or slightly below seasonal normals.


.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1201 PM CDT Sun Apr 16 2017

A few sprinkles possible late this evening across KHON and KFSD
sites. Otherwise VFR conditions will prevail through the TAF


Issued at 329 AM CDT Sun Apr 16 2017

Issued a red flag warning for Lincoln and Lyon counties in
southwest Minnesota for this afternoon and very early evening.
Very deep layer mixing, coupled with a westerly wind flowing over
the Buffalo Ridge, will likely locally enhance wind speeds to 20
to 30 mph this afternoon, coupled with minimum humidity values
near 25 percent. The rest of the highway 14 corridor from Huron to
Brookings South Dakota is also a concern. But at this time it is
expected that wind speeds will be a little lighter, averaging 15
to 25 mph in east central SD. Proceeding southward, the air mass
will also be dry with minimum humidity values in the lower to mid
20s percent. However the wind speeds will become progressively
lighter heading toward I 90 and points southward with the center
of a high moving right across that area.


MN...Red Flag Warning until 8 PM CDT this evening for MNZ071-072.



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