Area forecast discussion
National Weather Service Sioux Falls South Dakota
411 am CDT Tuesday may 21 2013
Short term...(today and tonight)
issued at 408 am CDT Tuesday may 21 2013
Upper level low continues to spin across the area with best lift and
moisture transport located across the northern and western portions
of the forecast area. Further to the east...instability showers may
develop...but with limited heating and instability...am not really
expecting much in the way of thunder/severe weather. With a fair
amount of cloud cover...temperatures should remain 10 to 15 degrees
below normal today.
Long term...(wednesday through monday)
issued at 408 am CDT Tuesday may 21 2013
Upper level low will continue to slowly wobble southeastward tonight
and Wednesday...with its center tracking across our eastern forecast
area tonight and into southeastern Iowa on Wednesday. Unsettled
conditions will persist tonight as the trowal continues to shift
east through the forecast area. Best potential for showers will be
across our northern forecast area tonight while much of northwest
Iowa will likely remain in the dry sector through the bulk of the
night and will see more isolated showers. With the low filling and
moving away from the region on Wednesday...scattered showers can be
expected across the County Warning Area in the morning then tapering off from west
to east in the afternoon and evening. Showers are expected to remain
generally on the light with most locations seeing less than a
quarter inch of additional rainfall. Persistent cloudy skies and
moist conditions will lead to another cool day on Wednesday with
highs only expected to reach the upper 50s and lower 60s.
Surface high pressure sinks southward on Wednesday night which
should finally allow the clouds to begin scouring out
overnight...however lows will be unseasonably cool in the low to middle
40s. While late week into early next week looks to resume the wet
pattern...temperatures will also be on a gradual warming trend.
Southwesterly upper level flow will direct several shortwaves
through the region and bring the potential for scattered
thunderstorms each period. Timing these waves remains
problematic...however all models do point to a very active pattern
during this time with several waves of precipitation.
&&
Aviation...(for the 06z tafs through 06z Tuesday night)
issued at 1054 PM CDT Monday may 20 2013
Large upper low will be drifting southward across the northern
plains tonight and Tuesday...greatly affecting the Sioux Falls
forecast area. In general...it appears mainly VFR conditions will
prevail south of I 90...with a lot of MVFR to even a bit of IFR
north of I 90. Rain will be wrapping down behind the low...
affecting areas west of I 29 late tonight and Tuesday morning...
then moving eastward along I 29 late Tuesday afternoon and
evening. In areas of rain...MVFR visibilities are certainly
possible with even some localized IFR at times. There is also a
possibility based on the latest NAM model that MVFR could move
into ksux late Tuesday and this will be watched.
&&
Fsd watches/warnings/advisories...
South Dakota...none.
Minnesota...none.
Iowa...none.
NE...none.
&&
$$
Short term.../
long term...
aviation...
