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Area forecast discussion 
National Weather Service Sioux Falls South Dakota
1217 PM CDT Monday Jul 28 2014

Short term...(today and tonight)
issued at 344 am CDT Monday Jul 28 2014

Shear vorticity axis across the eastern County Warning Area early this morning...
and weak impulse rotating by seems to have increased some of the
lower level /sub 850 hpa/ Theta-E advection and pushed a weak
frontogenetic axis into the extreme northeastern County Warning Area. A few
sprinkles and very light rainfall noted in parts of western/central
Minnesota and will likely rotate across the eastern tier or so through
the pre 12z time frame. Plenty of clouds Promise to persist along
and east of the i29 corridor through much of the day...and this
concerning to maximum temperature potential. Further west...will have
a better time heating...but will even lead to a lesser coverage flat
cumulus. Will probably be a fairly late day maximum...as some slightly
stronger subsidence and thinning of cloud layer evident even in the
North/East. Should range from lower 70s in the east...to near 80
west. Otherwise...fairly strong consensus of operational and
ensemble solutions indicate much of SW Minnesota/northwest Iowa will end up with
50-100 j/kg of shallow ml cape. Would still like to see some cloud
bearing temperatures creep into the sub zero c range...but even some lesser
efficient Mode for precipitation development should lead to isolated to
scattered coverage of showers east of I 29...starting by late
morning and continuing through the afternoon.

Going through the night...expect clouds to diminish and leave mainly
clear skies across the area overnight. Could be a few clouds
encroaching on the west from High Plains convective blow-off...and
even a few patches lingering across the far east. All in
all...should be a fairly decent radiative cooling night with
light winds and a dry air mass...so kept lows on the cool side of
guidance overall. The way temperatures have behaved tonight in clear
areas lends support to the cold numbers.

Long term...(tuesday through sunday)
issued at 344 am CDT Monday Jul 28 2014

An extended period of dry and pleasant weather is expected in the
middle and long range. A well amplified blocking pattern will persist
through the period with very little change in the upper level
pattern. Cool northwest upper flow will be the norm and continue to
bring unseasonably cool readings. Very weak flow...particularly at
the surface will also result in an extended period of unusually
light winds at the surface around less than 10 miles per hour. Skies will
generally be partly cloudy with some daily scattered cumulus in the
heat of the day. With a decent amount of sunshine...mixing should be
decent enough to continue following some of the warmer guidance for
daytime temperatures. A very subtle warming trend can be
expected...but not more than a few degrees through the entire
period. Highs will be in the upper 70s to middle 80s...perhaps
approaching 90 in south central South Dakota by the weekend.

Pattern remains dry with very little middle and upper level activity.
Any shortwaves of note continue to trend far enough to our east to
remain non events for the forecast area. Think precipitation chances
are too low for any mention through the period.

&&

Aviation...(for the 18z tafs through 18z Tuesday afternoon)
issued at 1215 PM CDT Monday Jul 28 2014

After a brief period of MVFR ceilings as the cumulus field formed late
this morning...ceilings should gradually lift to VFR levels early
this afternoon. Models hinting that cloud cover may again linger into
the night...but generally anticipating VFR conditions through
daybreak as winds turn light and variable.

&&

Fsd watches/warnings/advisories...
South Dakota...none.
Minnesota...none.
Iowa...none.
NE...none.
&&

$$

Short term...Chapman
long term...
aviation...dux

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