Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Sioux Falls South Dakota
601 PM CDT Monday Mar 30 2015
Short term...(this evening through tuesday)
issued at 257 PM CDT Monday Mar 30 2015
Red flag conditions will continue into early this evening with
blustery west to northwest winds and low relative humidity. Winds
will drop off tonight as high pressure settles in. Dropped lows a
bit given the clear skies and light winds...generally thinking 30s
for most of the area. Expecting a beautiful day Tuesday...with sunny
skies...warm temperatures and light winds. Highs west of the James
River will again be in the middle 70s...with readings a bit cooler than
today in the east with middle 60s to low 70s expected. It will be
another very dry day...but given the light winds...will not have to
worry about red flag conditions. Even towards Chamberlain think any
gusts by late afternoon should stay at 20 miles per hour or less.
Long term...(tuesday night through monday)
issued at 255 PM CDT Monday Mar 30 2015
Tuesday night will the the southeasterly low level flow and surface
winds increasing through the night. NAM and ec both show a decent
low level jet developing from the west and a fetch of instability and much
higher 800 mb dew points spreading toward the southeast corner of the
area. On a close call will hold of precipitation mention late
Tuesday night but put spotty middle based storms in for Wednesday
The cold front will enter and pass across most of the area
Wednesday. Still not enough support instability and moisture to
mention precipitation over the northwest part of the area. Some
significant storms possible southeast half in the afternoon to early
evening. Storm Prediction Center outlook is accepted for now even though the
unidirectional looking shear profiles do not look ideal in this
marginal early season moisture availability...marginal even given
the sharp increase mentioned above. But the instability looks pretty
good for the end of March.
Winds Wednesday will be fairly strong in the east ahead of the
front...and also behind the front from the northwest. This could
prompt elevated fire danger depending on the timing of the cold
front...which will likely have a band of lower winds with the wind
The storm threat...after concentrating over the southeast corner of
the area late in the day and early evening...should end steadily
later Wednesday as the strong short wave just to the north pushes
cooling and drying over the area. Expect that if anything remotely
close to a stalling of activity happens...it will be to the
south/southeast of the area.
With the clearing late Wednesday night...skies should be clear to
partly cloudy for several days with cooling Thursday and
Friday...and warming over the weekend. Models are in good agreement
on the timing of another system moving in Monday with another
Aviation...(for the 00z tafs through 00z Tuesday evening)
issued at 600 PM CDT Monday Mar 30 2015
VFR conditions expected through the taf period.
issued at 257 PM CDT Monday Mar 30 2015
Red flag warning looks good into early this evening with marginal
winds but more than enough dryness to verify.
Fire danger is likely to be elevated...very high to extreme...
Wednesday with the dry conditions and strong winds. Red flag
potential is marginal in the west with borderline humidities...and
not there with the higher humidities east. Complicated things is the
timing of the cold front as there is likely to be a zone of less
strong winds near the front...between the strong south/southeast
winds ahead and the strong northwesterly winds behind the front.
Thursday may also have concerns with the drier weather despite less
strong winds. Friday and Saturday seems less likely for problems the
increasing winds ahead of the Monday system could bring the danger
South Dakota...red flag warning until 8 PM CDT this evening for sdz255>258.
Minnesota...red flag warning until 8 PM CDT this evening for mnz900.
Iowa...red flag warning until 8 PM CDT this evening for iaz300-301.
NE...red flag warning until 8 PM CDT this evening for nez249.