Area Forecast Discussion
Issued by NWS Sioux Falls, SD

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS63 KFSD 272343

National Weather Service Sioux Falls SD
643 PM CDT Wed May 27 2020

.SHORT TERM...(This Evening through Thursday)
Issued at 145 PM CDT Wed May 27 2020

Persistent low lvl moisture axis remains stretched across the far
southeastern portions of the forecast area this afternoon.  Light
sprinkles or even a few showers may develop this afternoon along
this corridor where surface convergence is increased.  Elsewhere, a
very nice late May day continues with plenty of sunshine, light
winds, and temperatures approaching the 80 degree mark.   The short
term forecast in general remains very quiet.

Tonight: We`re expected a weak frontal boundary to move through
the area after midnight. Temperatures may fall quickly tonight
with light winds, but once the winds begin increasing, we may
stabilize or even warm temperatures a bit after midnight. An upper
trough will dip down into the Northern Plains after midnight,
with a weak band of mid- lvl frontogenesis moving southeast
through the Dakotas. Moisture remains marginal in this frontal
band, but it should be sufficient to produce showers across
central South Dakota. This activity will weaken as it moves into
the eastern Dakotas, but will still include a low end PoP until
the James River Valley dissipating to sprinkles.

Thursday: A breezy northwestern wind will persist through the day,
as slight cold advection moves through the region.  Temperatures
will cool slightly over today, with highs reaching into the lower to
middle 70s.

.LONG TERM...(Thursday Night through Wednesday)
Issued at 145 PM CDT Wed May 27 2020

Friday: High pressure drains southward on Friday leading to another
pleasant day across the region. As low level temperatures continue
to cool across the western side of the trough moving through the
Great Lakes, temperatures at the surface will also respond by
lowering into the lower 70s. With low humidity, a very nice Friday
is anticipated, but some afternoon CU will be possible.

Saturday: Models remain consistent in bringing a subtle shortwave
through the Northern Plains inducing broad warm advection through
the CWA.  The NAM remains a southern outlier with this wave,  CMC
slightly further north, with the GFS/ECMWF moving across the CWA.
Given the subtle nature of the wave and limited predictability on
the track, will not hedge the forecast either direction at this
time. Temperatures on Saturday will be the coldest of the upcoming
week as highs struggle to reach into the 60s.

Sunday-Wednesday: A large scale pattern shift is still anticipated
to start the new week as mid-lvl heights rise. This will signal
rising temperatures, likely with several days above normal.  The
latest CPC guidance supports this concept through much of next week
with high probabilities of above normal temperatures.  Sunday may
remain a slightly cooler than normal day the region remains under
the influence of Great Lakes high pressure and increasing mid-lvl
cloud cover. There remains a bit less agreement in staying
completely dry early next week, as some signals for passing
convection as warmer air builds in Monday into Tuesday.


.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 643 PM CDT Wed May 27 2020

VFR conditions are likely through 00z Thursday. A band of mid-
level clouds will drop southward across the area later tonight and
early Thursday with potential for a few light showers, but not
expected to bring any appreciable periods of non-VFR conditions.
North to northwest surface winds could occasionally gust to
around 25 knots starting mid-morning.




AVIATION...Chapman is the U.S. government's official web portal to all federal, state and local government web resources and services.