Area Forecast Discussion
Issued by NWS Aberdeen, SD

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FXUS63 KABR 270833

Area Forecast Discussion
National Weather Service Aberdeen SD
333 AM CDT Tue Jul 27 2021

.SHORT TERM...(Today through Wednesday Afternoon)
Issued at 333 AM CDT Tue Jul 27 2021

The upper level high pressure area will make its move today and
build over the central U.S. resulting increasing heights over our
region. As this occurs, surface pressures will fall off to our
northwest today. This will result in the boundary stretched across
our cwa this morning moving back north as winds all become southeast
through the day. The main issue today and Wednesday will be the high
temperatures, humidity, and subsequent heat index values. Dewpoints
early this morning were already high in the upper 60s and lower 70s
south of the boundary. As the boundary moves north today, so will
the higher dewpoints. Although, as the mixing layer develops, much
of these dewpoints will lower. Overall, for today through Wednesday
the models show much of the east remaining humid with lower
dewpoints along and west of the river. We also have to consider the
smoke aloft and its affect on the high temperatures for both today
and Wednesday. On Wednesday, the models all show the surface
boundary that moved north today pushing back south with winds
turning north northeast through the day across our cwa. The
consensus continues to show high temperatures ranging from the mid
90s east to around 105 degrees west both today and Wednesday.
Combining in the humidity, heat index values are expected to make it
to 100 to 105 degrees today and maybe a little higher on Wednesday.
Therefore, continued with the heat advisory for today and will issue
one for Wednesday. As far as rainfall chances, the ops models and hi-
res models show some showers/storms sliding across our northeast cwa
tonight into early Wednesday. Thus, have chances in for this region.

.LONG TERM...(Wednesday Evening through Monday)
Issued at 333 AM CDT Tue Jul 27 2021

As the period begins Wednesday night into early Thursday, a frontal
boundary is progged to be pushing swd and exiting out of our
forecast area. There may be some leftover post-frontal
showers/storms Wednesday night in parts of our eastern zones, but
the bulk of any activity should be shifting east-southeastward into
MN. A drier, cooler airmass will shift southward into the area on
Thursday as temps look to be back closer to seasonal averages for
late July.

More s/w energy is anticipated to ride up and over the top of the
upper ridge and across portions of the region Thursday night into
Friday. This combined with a sfc boundary and low pressure wave
setting up southwest of our forecast area should be enough to
generate increasing chances for pcpn across our western and
southwestern zones. This system looks to exit the region by the
upcoming weekend. For the remainder of the period, the upper ridge
that`s been a dominant feature lately is progged to get squashed to
the south and western part of the CONUS. Sfc high pressure will
build into the Dakotas during the upcoming weekend. Temperatures
will remain warm, but around where this should be for this time of


.AVIATION...(For the 06Z TAFS through 06Z Tuesday Night)
Issued at 1245 AM CDT Tue Jul 27 2021


VFR conditions are expected through the next 24 hours.


SD...Heat Advisory from 1 PM CDT /noon MDT/ this afternoon to 7 PM
     CDT /6 PM MDT/ this evening for SDZ003>006-009>011-015>023-

     Heat Advisory from noon CDT /11 AM MDT/ to 7 PM CDT /6 PM MDT/
     Wednesday for SDZ003>011-015>023-033>037-045-048-051.

MN...Heat Advisory from noon to 7 PM CDT Wednesday for MNZ039-046.



LONG TERM...Vipond
AVIATION...Mohr is the U.S. government's official web portal to all federal, state and local government web resources and services.