Area Forecast Discussion
Issued by NWS Aberdeen, SD

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FXUS63 KABR 231745 AAB

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1245 PM CDT Sun Apr 23 2017

Issued at 1230 PM CDT Sun Apr 23 2017

Current analysis suggest the warm front is currently along Highway
12, where surface obs indicate easterly winds. South of the front,
temperatures have warmed in the 60s, with 70s likely this
afternoon. Cross the border into North Dakota and temperatures are
struggling to reach the low to mid 40s. Still anticipate the front
pushing a bit further north with locations along Highway 12
peaking into the mid 60s.


.SHORT TERM...(Today through Tuesday Afternoon)
Issued at 326 AM CDT Sun Apr 23 2017

The cold front extends to the county lines of Beadle and Spink,
extending northeast and northwest from there. CAM solutions are
generally agreed that this feature will move back to the north
during the day - though the finer details of the end destination vary
slightly. This will have a huge impact on the temperature forecast
for locations such as Aberdeen - where the going high is around 70
with NAM BUFKIT soundings mixing us up to 750mb - however if the
front fails to make it this far north - we could be seeing highs
that struggle to make 60. This example plays out across the northern
tier of counties for South Dakota today.

A low will develop along the front tonight across western South
Dakota. As this low moves east during the day, we develop a stronger
push of colder air southwards on the west side of the low. Milder
air will remain just to the east however, so again there will be a
strong contrast in temperatures even through Monday.

As for precipitation, the fairly aggressive GFS CAPE values peak
around 700mb into eastern counties. The GFS soundings don`t really
support this however, and much like the NAM BUFKIT soundings -
suggesting around 300 j/kg elevated/skinny cape, anticipate more of
a showers/rumble of thunder type environment.

Cold air will dominate conditions Tuesday, with 925mb temperatures
down to around +2C and 850mb temperatures between -6 and -4C.
Another system moves across the southern tier of the CWA. Profiles
support a rain/snow mix or possibly all snow along the northern edge
of this system with some wet bulb effects. With ground temps in the
40s to around 50, this should help melt off any accumulation so long
as the snow intensity remains light.

.LONG TERM...(Tuesday Evening through Saturday)
Issued at 326 AM CDT Sun Apr 23 2017

Compared to 24 hours ago, the 00Z deterministic solutions are 1-3C
cooler with their 925hpa thermal progs for Tuesday night through
Wednesday night with meager (at best) temperature recovery Thursday
and Friday. Again, Superblend is too warm for the middle of the
week. Eventually, forecast lows and highs through that period will
need to be lowered a solid category or more of temperature, if these
low level thermal progs continue. Between Tuesday night and Saturday
night, the only timeframe where there is any semblance of model
agreement is Saturday/Saturday night when the potential for a large
sw conus upper low is forecast to lift north-northeast across the
plains. Otherwise, spotty chances for precip from hit-or-miss
transient shortwaves in split flow upper level pattern continues.


.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 1230 PM CDT Sun Apr 23 2017

A warm front just south of the ND/SD border will cause easterly
winds for the terminals of KMBG and KABR through this afternoon.
South of the front, expect breezy southwesterly winds. A low
pressure system crossing the region tonight through Monday morning
will bring vicinity showers to all terminals. MVFR conditions will
be possible with some heavier showers.




SHORT TERM...Connelly
AVIATION...SD is the U.S. government's official web portal to all federal, state and local government web resources and services.