Area Forecast Discussion
Issued by NWS Aberdeen, SD

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FXUS63 KABR 112057

Area Forecast Discussion
National Weather Service Aberdeen SD
357 PM CDT Tue May 11 2021

.SHORT TERM...(This Evening through Wednesday Night)
Issued at 357 PM CDT Tue May 11 2021

The center of high pressure will continue to slowly move away from
the region overnight and into Wednesday. This will allow for a
pressure gradient to tighten over the region. Light southerly winds
overnight should be just enough to prevent lows from falling below
freezing. These southerly winds will become breezy and gusty on
Wednesday, but staying below advisory levels. A slight increase in
the overall 850mb temps combined with the extra mixing should allow
for temps to be a few degrees warmer than what we saw today. RH on
Wednesday looks to fall into the 20 to 30 percent range across most
of the CWA, with the lowest readings across the far eastern portion.
Green-up has progressed quite a bit, but still an elevated fire
danger nonetheless. A weak disturbance and subtle surface boundary
may bring a few scattered showers/thundershowers to western SD
during the afternoon hours on Wednesday, with some of this activity
trying to reach the far western CWA by 00Z Thursday. Hi-res guidance
suggests this activity will be widely scattered at best by the time
any potential activity makes it to our CWA. Will leave slight chance
PoPs in the forecast for the time being. A weak low-level jet
development across south central SD Wednesday night may bring an
additional chance for a few showers, as noted on CAM solutions.

.LONG TERM...(Thursday through Tuesday)
Issued at 357 PM CDT Tue May 11 2021

A fairly active pattern with several chances for precipitation is
forecast through the long term. Beginning on Thursday, a couple
shortwaves in NW flow aloft will provide lift for potential rain
showers during the afternoon and again overnight into Friday
morning. Instability is lacking for the most part during this time,
with high temperatures in the 60s and dewpoints in the 40s, but
there may be occasional lightning strikes associated with this
activity. Southerly winds will gust into the 30mph range
across the eastern CWA on Thursday afternoon as well.

Westerly flow develops aloft ahead of another shortwave this
weekend, positively tilted. Chances for precipitation have increased
some, though there`s still uncertainty regarding the details such as
when and how much. Given the cloud cover, high temperatures may be
held in the 60s to around 70 degrees. Models diverge on whether to
build in an upper-level ridge for the new work-week (most GFS
ensemble members) or build in an upper-level trough. Whichever
happens will dictate what kind of weather plays out across the
Northern Plains.


.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1237 PM CDT Tue May 11 2021


VFR conditions are forecast to prevail through the TAF forecast




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