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000
FXUS63 KFSD 060851
AFDFSD

AREA FORECAST DISCUSSION
National Weather Service Sioux Falls SD
351 AM CDT Thu May 6 2021

.SHORT TERM...(Today through Friday Afternoon)
Issued at 351 AM CDT Thu May 6 2021

A couple of quiet days across the area, with the main concerns being
marginal fire conditions today, and a couple of subtle waves sliding
through Minnesota and northern Iowa through this evening.

Temperatures remain a few degrees shy of normal today and Friday,
but still looking at marginal humidity levels with regard to fire
weather concerns, bottoming out largely in the 20-25 percent range
today, and 20-30 percent on Friday. Winds are also marginal today,
with occasional gusts 25-30 mph possible this afternoon. However,
rising greeness levels in the fine fuels, combined with the light
rainfall yesterday, should hold fire danger shy of critical levels,
though will still be elevated near/east of I-29 where greenup is
lagging more than in areas to the west. Even lighter winds expected
Friday as broad surface ridge settles into the eastern Dakotas.

As alluded to above, low levels remain quite dry over the next 24-36
hours. That said, models consistent in showing a couple of weak mid
to upper level waves dropping south through Minneota/Iowa. The first
currently generating a patch of clouds and very spotty light showers
in west central Minnesota, but this activity has been weakening as
it moves south through the early morning. A second slightly stronger
wave brushes our far eastern areas this evening, and while moisture
is questionable, will carry some low pops to account for possible
light showers/sprinkles, though better chance for any measurable
rain does look to remain east of the forecast area.

Any clouds from this wave expected to clear through the late night
hours, but winds currently expected to remain in the 5-10mph range
most areas, which should help hold temperatures up in the mid-upper
30s, and limit patchy frost potential to sheltered/valley areas.


.LONG TERM...(Friday Evening through Wednesday)
Issued at 351 AM CDT Thu May 6 2021

First half of the weekend will be watching rainfall potential,
especially across western/southern portions of the forecast area, as
a cutoff upper low slowly digs southeastward through the northern
Rockies. Modest low-level thermal gradient near and south of the
Missouri River Valley early Saturday, pivots even farther south
through the remainder of the day as surface low develops across
eastern Colorado and pushes into the central Plains. This should
keep any substantial instability well south of our area, with some
concern in just how far east into a drier easterly flow any rain
will be able to advance away from the supporting baroclinic zone.
Made some minor adjustments to trim pops in southwest Minnesota for
now, but further adjustments may be necessary to tighten up the
eastern edge of the precip potential for Saturday into Saturday
night. Could see a few light showers linger into Sunday, mainly
south of I-90, but overall that should be the drier day of the
weekend. The rain and/or more extensive clouds will keep daytime
temperatures on the cool side, with highs largely in the 50s through
the weekend.

Subtle mid-upper level ridging across the forecast area through the
first part of next week, as the weakening western trough meanders
across the Intermountain West. Temperatures rebound, but remain on
the cool side of normal, with minimal precipitation chances during
the week ahead. Overnight temperatures could still cool enough to
allow for patchy frost development at times, but not currently
seeing conditions favoring widespread frost or freeze.


&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1021 PM CDT Wed May 5 2021

MVFR ceilings will continue to shift eastward but may still impact
areas along and east of a FSD to SUX line before 12z. Otherwise
VFR conditions should prevail through the forecast period. Expect
north winds to gradually weaken overnight as sfc high pressure
builds in. Winds will increase with mixing Thursday morning.
During the afternoon, expect gusts up to 25 kts and diurnally
driven mid level cumulus.


&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Frost Advisory until 8 AM CDT this morning for SDZ038>040-050-
     052>069.

MN...Frost Advisory until 8 AM CDT this morning for MNZ071-072-080-
     081-089-097-098.

IA...Frost Advisory until 8 AM CDT this morning for IAZ001.

NE...NONE.
&&

$$

SHORT TERM...JH
LONG TERM...JH
AVIATION...BP