Area Forecast Discussion
Issued by NWS Aberdeen, SD
FXUS63 KABR 181554 AAB
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1054 AM CDT Tue Apr 18 2017
Issued at 1047 AM CDT Tue Apr 18 2017
Plenty of low clouds have wrapped in behind the departing low
pressure system over the past few hours. Short range model
guidance continues to suggest these clouds remain in place through
much of the day, with gradual breaks/erosion by later in the
afternoon, or perhaps not even until this evening. Feel this,
along with the coolish 925/850mb temps will act to keep highs a
few degrees cooler than anticipated. Have therefore dropped highs
a few degrees in locations affected most by cloud cover. Also had
to increase sky cover across much of the CWA, following a
CONSSHORT flavor in the grids. Otherwise, other weather elements
appear on track for today, with breezy northwest winds expected
and dry conditions. Winds will begin to lighten up by late
afternoon as the surface ridge slides in.
.SHORT TERM...(Today through Thursday Afternoon)
Issued at 413 AM CDT Tue Apr 18 2017
Convection now into the Sisseton hills region will continue to move
swiftly to the east/northeast, with some wrap around showers
lingering back in north central counties. NAM BUFKIT profiles dry
through the course of the morning, but also that daytime heating
will result in scattered/broken shallow capped cumulus.
Additionally, there is a weak/localized pressure bubble following
the system, which will result in a stiff northwest breeze this
morning across northeast counties, and mixed down winds are close to
High pressure nosing down out of Canada will provide for weak cold
and dry air advection today, and generally temperatures will be
The next system begins to move into the region tonight. There are
actually two distinct waves, embedded within zonal flow, and
result in two weak low pressure centers that eventually
consolidate across Nebraska. The initial wave will have to contend
with dry northeast flow and NAM BUFKIT profiles show a dry layer
below 8kft. Lift is initially weak, so much of this could be
virga. Omega values are quite high thereafter, and I suppose this
is guidance trying to phase a left exit and right entrance region
between two jet maxes. Profiles during that time are also just
barely above melting, with temperatures in the lowest 5kft ranging
between +0 and +2C. Will stick with all rain mention - but cant
rule out a localized location or two transitioning over to snow.
MUCAPE values are less than 100 J/KG so will continue to omit any
mention of thunder.
High pressure will follow for Thursday with cooler mid level
temperatures and a dry low level airmass.
.LONG TERM...(Thursday Evening through Monday)
Issued at 413 AM CDT Tue Apr 18 2017
The majority of the extended period looks to be dry at this time
with high pressure in control Thursday night through Saturday night.
A low pressure system and associated frontal boundary will approach
the area Sunday, then tracks through Sunday night and Monday,
possibly bringing precipitation with it. There does look to be some
weak shear around, but instability will be nearly non-existent.
Therefore, will keep the precipitation mention as rain showers.
Temperatures will be near to slightly above normal through the
period, with highs in the 60s and lows in the mid 30s to lower 40s.
.AVIATION...(For the 12Z TAFS through 12Z Wednesday Morning)
Issued at 623 AM CDT Tue Apr 18 2017
An area of lingering MVFR/IFR cigs behind an exiting low pressure
system will affect a good portion of the CWA through the morning
hours, and possibly into the early afternoon. VFR conditions will
then prevail through the remainder of the TAF period, with just
some light rain showers moving into the southwestern CWA after