Area Forecast Discussion
Issued by NWS Aberdeen, SD
FXUS63 KABR 211542 AAA
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1042 AM CDT WED SEP 21 2016
Issued at 1042 AM CDT WED SEP 21 2016
Stratus clouds have been developing/expanding across the southern
part of our cwa from Pierre over to Watertown this morning. While
across the rest of the cwa there was only some mixed layer clouds
along with mid and high level clouds moving over. Also,
breezy/windy east to northeast winds at 15 to 30 mph were
occurring and bringing in cooler air. Thus, temperatures will be
affected by the cloud cover and caa. Otherwise, cut back on pops
across the eastern cwa for this afternoon.
UPDATE Issued at 624 AM CDT WED SEP 21 2016
See updated aviation discussion below.
.SHORT TERM...(Today through Friday)
Issued at 331 AM CDT WED SEP 21 2016
Quite a contrast across SD, from the 50s dewpoints across much of
the state to mid 70s over the far southeastern corner. Cooler and
breezy conditions will set up over our area today. Temperatures will
be 7-13F lower today that what was observed Tuesday afternoon. The
weather map early this morning features a sfc low across western and
central NE, with a trough extending up through southeastern SD and
southern MN. The main focus for showers through tonight will remain
over our eastern SD and west central MN counties. Looks like the
stratus will hold off until later this afternoon/evening, with
plenty of moisture settling in below 800MB through at least Friday
morning. While it will be difficult to get rid of the slight chance
of thunderstorms, severe weather is not expected through the period.
Low pressure will become better organized across eastern CO/western
NE on Friday, with a warm front riding up across our southern
counties. This will result in the best chance of at least some
clearing over central SD Friday afternoon.
.LONG TERM...(Saturday through Tuesday)
Issued at 331 AM CDT WED SEP 21 2016
Mid level ridging will be over the area at the beginning of the
extended period, with a deep trough over the Rockies. Shortwave
energy will begin to swing toward the Northern Plains Friday night,
then settles in over the central part of the country through the end
of the period, keeping shortwave energy over the region.
Friday evening, surface low pressure will be over the western high
plains, with precipitation likely ongoing over parts of the CWA.
There may be a break in the precipitation before the low pushes
northward late Friday night and Saturday, with an elongated band of
precipitation likely developing and tracking across mainly the
central and eastern CWA late Saturday afternoon and Saturday night.
The models differ some on what the low does after that, with the
ECMWF keeping wrap around showers north of the area, while the GFS
keeps the low a bit stronger and drops wrap around precipitation
over the eastern CWA Monday and Monday night. Will stick fairly
close to Superblend during this time. High pressure moves back in
and bring dry conditions on Tuesday.
Saturday will be the warmest day of the period, with highs in the
70s. Cooler air then moves in, with highs in the 60s through the
rest of the long term. After a couple of mild nights with lows in
the upper 50s to mid 60s Friday night, and in the 50s Saturday
night, lows will be the 40s through the rest of the period.
.AVIATION...(For the 12Z TAFS through 12Z Thursday Morning)
Issued at 624 AM CDT WED SEP 21 2016
VFR conditions will prevail across the area today. Scattered
showers and thunderstorms are expected to develop over the eastern
CWA late this afternoon into this evening. IFR/MVFR cigs will
overspread the area this evening and overnight, along with the
potential for some MVFR vsbys in fog across the east.