Area Forecast Discussion
Issued by NWS Aberdeen, SD

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FXUS63 KABR 241645

Area Forecast Discussion
National Weather Service Aberdeen SD
1145 AM CDT Mon Jul 24 2017

Issued at 1132 AM CDT Mon Jul 24 2017

MCV/weak shortwave moving across the area with light showers/weak
convective activity. This will likely impact temperatures today,
particularly along and east of the James valley due to the slow
movement east, resulting in widespread high cloud. Given
uncertainty and advertised highs in the mid 80s - opted not to
make any changes to temperatures. Clearing in western counties
means that temperatures there, with warm advection and a weak low
resulting in a southwest component around and south of Pierre will
still result in temperatures topping the century mark.
Additionally, uncertain about how the dewpoints will react to
southwest counties still lacking surface moisture and thus should
experience even deeper mixing. Initial feelings are that we will
probably not see heat index values much higher then 100, but its
close so will leave headlines in place.

Only updates other then POPs and sky cover to account for
progression of MCV is to increase winds which are already gusting
into the 20 to 30mph range. Mixed winds in BUFKIT profiles top out
around this level so not expecting a marked increase over what is
already occurring.


.SHORT TERM...(Today through Wednesday Afternoon)
Issued at 419 AM CDT Mon Jul 24 2017

Watching a decent looking shortwave move eastward into western SD,
with a fairly expansive area of showers and storms over UNR`s CWA.
Hi-res models picking up on this somewhat and pushes this activity
eastward across the CWA through the day. This is a bit of a change
from 24 hours ago. This could keep temps down a touch as well,
mainly over the northern James valley region where models are
showing scattered showers and clouds around mid-day into the
afternoon. Shaved just a few degrees off highs, but still expect
temps to get fairly warm. Over the western CWA it`s still looking
pretty hot as this shortwave will be east of the area by afternoon
as strong warm air advection and very warm 850mb temps move in.
Still forecasting highs in the low 100s over the southwest CWA, thus
prompting a Heat Advisory as heat indices are also in that range.
The southwest CWA also butts up against Red Flag criteria today, so
looking at very high fire danger in that region.

Tuesday continues to look hot, but a frontal boundary will be
sagging southward over the area through the day. Still expecting the
atmosphere to become unstable during the afternoon hours, with a bit
of shear developing as well - although the best shear is further
north. Severe parameters continue to support strong to severe storm
potential over eastern SD into MN Tuesday afternoon and evening, but
would like to see bulk shear values a little higher.

Cooler air moves southward into the region on Wednesday as a surface
high builds in. Rain chances begin to dwindle as a drier and more
stable air mass moves in. After rather hot highs in the 90s on
Tuesday, temps will fall back into the 80s on Wednesday.

.LONG TERM...(Wednesday Evening through Sunday)
Issued at 419 AM CDT Mon Jul 24 2017

A strong mid level ridge will again remain anchored over the south
central/southwest conus through much of the period. Over the
Northern Plains a sfc high will provide for generally dry conditions
and seasonable temperatures to start the period. However, mid level
heights will begin to climb across much of the region by the weekend
as ridging aloft re-asserts itself over the western high plains. The
rising heights/rising mid level temps will likely provide for
capping across the region, thus chances for pcpn at this time look
minimal.  The best chance of rain for the period might be toward the
end of the forecast as a frontal boundary slides into the region.
Temperatures will start the period off near normal but should trend
toward above normal by the weekend or early next week.


.AVIATION...(For the 12Z TAFS through 12Z Tuesday Morning)
Issued at 617 AM CDT Mon Jul 24 2017

A system aloft will track across the region today and produce
isolated to scattered showers and thunderstorms. The terminals
that are expected to see the majority of the activity are
KMBG/KABR. KATY/KPIR appear to have lesser chances thus tsra has
not been placed into those tafs. Overall VFR conditions are
expected at all terminals.


SD...Heat Advisory from 3 PM CDT /2 PM MDT/ this afternoon to 8 PM
     CDT /7 PM MDT/ this evening for SDZ033-045-048.



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