Scientific Forecaster Discussion
fxus63 kunr 220453
Area forecast discussion for western South Dakota and northeastern Wyoming
National Weather Service Rapid City South Dakota
1053 PM MDT Sat Sep 21 2019
Discussion...(this evening through saturday)
issued at 1248 PM MDT Sat Sep 21 2019
Water vapor shows upper low over ND with trof extending southwest
into the desert SW. Upper ridge building into the pac northwest. Gusty
northwest winds continue early this afternoon across the region. A
few showers continue from northeast Wyoming into northwest SD, but not
as numerous as previously anticipated.
Lingering showers will come to an end quickly this evening with
loss of heating. A secondary low may bring an isolated shower or
two late tonight into early Sunday, but most areas will remain
dry. Quite chilly overnight as surface high builds in, with temps
down into the 30s/40s.
Upper ridge currently over the pac northwest advances quickly eastward
into the northern rockies Sunday and northern plains Monday. Temps
will warm well into the 60s/lower 70s Sunday and 70s to lower 80s
Monday with dry conditions expected.
More unsettled conditions expected as early as Tuesday and
continuing into next weekend. Northern stream will become active
by midweek, then a deep upper low/trof develops over the western
Continental U.S. Late in the week. Temps will cool for midweek, then remain
near or slightly below average for the end of the week into the
Aviation...(for the 06z tafs through 06z Sunday night)
issued at 1053 PM MDT Sat Sep 21 2019
VFR conditions are generally expected through the taf period. Rain showers
and a few thunderstorms and rain will develop across nern Wyoming/swrn South Dakota late tonight,
which could lead to some brief, local reductions to MVFR
conditions. This activity should end by 18z on Sunday.