506
FXUS63 KABR 120154 AAB
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
854 PM CDT Fri Jul 11 2025

.KEY MESSAGES...

- Wildfire smoke will return for Saturday, both aloft and near the
  surface. Visibility during the early morning hours may be
  significantly reduced as it heads into the northern tier of
  South Dakota.

- The potential exists for a noticeable cool-down during the
  middle of next week (temperatures 10 to perhaps 15 degrees below
  normal).

&&

.UPDATE...
Issued at 849 PM CDT Fri Jul 11 2025

Much of the light shower activity this evening has been confined
to the Hwy 14 corridor and points south. Had earlier this evening
adjusted PoPs to better match radar trends, which also included
removing rain chances to below "mentionable" (20%) across the
northern CWA. Also increased sky cover to better align with
satellite trends. Main forecast issue will the increase in smoke
aloft and at the surface late tonight into Saturday morning.
Current forecast has a good handle on this but may make additional
updates once 00Z HRRR data arrives.


&&

.DISCUSSION...
Issued at 226 PM CDT Fri Jul 11 2025

Front has cleared the CWA, with smoke lingering though with improved
visibility. Showers on the backside of  the front have dropped in
coverage since this morning, however down by Clear Lake we do have a
cumulus field bubbling up. Still some high instability with 21Z NAM
indicating about 3K j/kg MLCAPE, though that does progress out of
the CWA by 00Z, and a few CAMS show a blowup over the far southeast
CWA, though fewer CAMS in comparison to earlier runs have storms
back this far.  Shear in this area is relatively weak however.

NAM BUFKIT profiles even  indicate that back towards Aberdeen we
could reach our convective temperature, however with lowering
dewpoints and moist mid-levels, its a skinny CAPE profile, though
with stronger mid level flow than in comparison to down by
Watertown. Regardless, CAMS are not too impressed with the convective
potential out this way despite our closer proximity to the upper
level wave... though we have seen some blow ups just east of Wheaton
already this afternoon. Additionally, another area of rainfall is
headed in from west-river into the Pierre area.

For Saturday, NBM high temps are in the 80s, and 70s over in the
east. The big question is how will smoke, elevated and at the
surface, impact temperatures. HRRR concentration of both near
surface and elevated smoke are mainly during the first half of the
day, confined to about the James valley and points east, while the
RAP is a little broader and lingers overhead longer. This should
knock about 3 degrees down for Aberdeen/Redfield and points east.
NBM box and whisker only shows we have about a 1-3 degree range in
highs for Saturday (high confidence) but does`t account for smoke.
Counterpoint when it comes to temperatures Saturday, we also have a
favorable mixing wind direction.  Despite this, will go below the
NBM 25th percentile in the eastern CWA.

Zonal, west to northwesterly flow regime sets up for early next
week. Either one or two weak waves (depending on model) associated
with the southwest monsoon gets caught up in the stronger westerlies
and is then pulled across the Northern Plains late Monday-Tuesday
timeframe. A front also comes down Tuesday as high pressure moves
into south central Canada. Thus, have a broad timeframe for
low/moderate POPs. Machine learning/AI severe weather models are
mixed with regards to severe weather potential in during this
time period, with NCAR medium range convective hazard forecast
highlighting Monday, while CSU and CIPS are both clear of threats.

This flow regime will also result in hot conditions, though with a
drier airmass despite the level of corn maturity, especially Sunday
with more of a westerly wind component, with return flow Monday
brining in the juicier airmass just as a front comes through to knock
it back down again.

Still looking forward to cooler temperatures for the middle of next
week. NAEFS 850mb thermal anomalies are down to a standard deviation
below climo starting 00Z Wednesday and lasts into Friday morning.
Unfortunately, while the heat and humidity will be turned off for a
bit, we may still have to deal with Canadian smoke. Additionally,
guidance directs two waves over this cool airmass so we will need to
contend with precipitation.  At these timescales, confidence in
either`s impacts is pretty low, but something to watch for the next
few days.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 645 PM CDT Fri Jul 11 2025

Terminals KABR,KATY,KPIR,KMBG

Area of -SHRA continues across the KPIR region at the start of the
period. Should be out of the vicinity by around 03Z. Otherwise,
surface smoke (FU) is expected to spread southward across the
region on Saturday, with MVFR/IFR VSBY possible. Lesser chance for
KPIR to be affected by FU.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&

$$

UPDATE...TMT
DISCUSSION...07
AVIATION...TMT