Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/04/17

Area Forecast Discussion

National Weather Service Sioux Falls SD

 524 PM CST Fri Feb 3 2017

.SHORT TERM...(This evening through Saturday)
Issued at 304 PM CST Fri Feb 3 2017

Temperatures and winds will be the main concern for tonight and
Saturday. South-southwesterly flow aloft increases late evening
through the overnight hours, with a low level jet around 40 to 50 kt
developing across much of the region late tonight. Southerly winds
at the surface will become gusty as well, reaching 15 to 30 mph with
gusts to 40 mph. Strongest winds will be focused in southwest
Minnesota and parts of south central SD. Used a blend of the CONSMOS
and HRRR wind guidance. Think that winds will generally remain below
advisory criteria for most locations, but may briefly spike up at
times. Not planning on issuing an advisory at this time. Mid to high
clouds increase from the west this evening, which along with the
strong southerly flow, will keep temperatures mild overnight. We
will likely see temperatures bottom out this evening before slowly
rising late tonight into Saturday morning.

Cold front slowly tracks east through the region on Saturday,
beginning in south central SD late morning. Gusty south-southwest
winds persist ahead of the front and decent mixing will allow
temperatures to warm near to just above freezing for much of the
region. Kept highs on the warm side of guidance. Frontal passage
should remain dry, with relatively dry lower levels remaining in
place.

.LONG TERM...(Saturday night through Friday)
Issued at 304 PM CST Fri Feb 3 2017

Saturday night into Sunday morning will see a cool surface high
pressure filter south through the Dakotas. This ridge of high
pressure will settle into the James Valley late Saturday night and
should provide some decent radiational cooling, assuming cloud
cover remains in check. At this time there does not appear to be any
major problems with clouds so will aim for single digits in central
and northern parts of the James Valley to as mild as around 20 in
parts of northwest IA where the wind should remain around 10 mph or
so into Sunday morning.

Sunday should be a fairly pleasant day without too much in the way
of wind or cloud cover. Should see highs from the mid 20s along
highway 14 to the mid 30s along the Missouri River.

South to southeast flow will gradually increase Sunday night into
Monday so lows and highs will be milder. Some question on Monday on
just how well we can mix and whether or not we will try to get some
stratus to develop as the surface to 925mb dew points looking to
increase to around 32 degrees or so. If these higher dew points
interact with a cold ground, especially if we can melt a little snow
on Saturday and Sunday, we may see fog and stratus develop. So, will
not go too warm on Monday because of this.

Monday night into Tuesday will see a northern stream wave helping
cold air settle south into the Dakotas while a southern stream jet
moves into Nebraska and Kansas and tries to bring broad support for
precipitation across the enhancing low and mid level boundary.
Initially Monday night into early Tuesday the layer just above the
surface to about 800mb remain a bit mild and dry so precipitation
with some of the better lift may not happen. But by Tuesday
afternoon and evening as cold air deepens so does the dendritic
layer so the chances for snow increase during this time as some lift
and saturation look likely. So, will raise pops a little from what
was initialized and increase winds too as the models are in pretty
good agreement on a strong pressure gradient.

Wednesday into Friday will see this fast moving, progressive pattern
continue with cold conditions on Wednesday, rebounding temperatures
on Thursday and warmer on Friday. And hopefully this will be the
start of a slightly more extended period of warmer conditions as we
head into the next week.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 522 PM CST Fri Feb 3 2017

VFR conditions expected through the TAF period. Southerly winds
will pick up after 03Z tonight, gusting to around 25 kts at times
through Saturday afternoon.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.
&&

$$

SHORT TERM...
LONG TERM...08
AVIATION...JM