Scientific Forecaster Discussion
fxus63 kfsd 170452
Area forecast discussion
National Weather Service Sioux Falls South Dakota
1052 PM CST Sat Nov 16 2019
Short term...(this evening through sunday)
issued at 234 PM CST Sat Nov 16 2019
Another mild day under filtered sunshine with temperatures into the
upper 40s and 50s for most locations. Surface front has worked into
central South Dakota with winds shifting out of the northwest behind it
along with a thickening cloud deck.
Expect clouds to continue to expand and thicken into the evening
hours with a band of precipitation, currently evident on radar to
our west, working through during this time frame. Surface
temperatures should stay above the freezing mark thus keeping the
predominant precip type rain and with the narrowly forced nature of
this band, any light rain should be fairly short lived. Inherited
high chance to likely pops still look good with the vast majority
of guidance and ensemble members showing some form of very light
quantitative precipitation forecast. Band of precip quickly works east prior to daybreak and while
some guidance wants to hang on to a few sprits thru the morning
hours, broad subsidence should put an end to any meaningful
Northwesterly winds and enhanced cloud cover to start the day will
keep sunday's high temperatures on the cooler side, back into the
upper 30s and 40s.
Long term...(sunday night through saturday)
issued at 234 PM CST Sat Nov 16 2019
Next shortwave is not far behind for Sunday night into Monday
morning, sneaking down in the northwest flow. This will again likely
bring some very light precipitation chances to the area and have
worked precip chances above blended guidance which is likely too
low, particularly for Monday morning. Forecast soundings again
indicate that much of this precipitation will fall as liquid. While
surface temperatures look to remain above the freezing mark, there
may be a brief window along and east of I-29 where very light
freezing rain may be a concern depending on the eventual timing
of any precipitation and modifying temperatures. At this time, the
concern is fairly low. Afternoon temperatures will warm back into
the mid 40s to mid 50s for most.
Ridge axis migrates east for Tuesday along with a more west to south
component to the surface winds. Combined with mid level warming,
this usually proves to be favorable conditions for warming and thus
pushed temperatures toward the 75th percentile.
By middle to late week, upper level trough rebuilds over the
western Continental U.S. As a cut off low settles into the desert SW. This
will help increase cloud cover and cool temperatures for
Wednesday. The first piece of energy off this trough will also
begin to ride up toward our region by Wednesday evening/overnight.
GFS is still the most aggressive and furthest north with the
general consensus to still keep the bulk of the activity south.
Any precipitation would likely start as rain but with cold air
crashing in, wintry precipitation would become an increasing
concern. Overall, a fairly messy pattern with many moving parts
so will continue to watch but seemingly not a huge impact to our
immediate area at this time. High temperatures cool back into the
30s for Thursday with perhaps some moderation for Friday. Winds
may also be underdone on in the blended guidance depending on the
eventual evolution of this system.
Aviation...(for the 06z tafs through 06z Sunday night)
issued at 1043 PM CST Sat Nov 16 2019
Light rain showers will move out of the region overnight. Behind
these showers, low clouds/stratus filter in bringing MVFR ceilings
at all terminals. Conditions will gradually improve to VFR by
early Sunday afternoon. Northwest winds will dominate the period
with gusts up to 20 knots on Sunday afternoon. North winds will
shift to the south by Sunday evening.