872
FXUS63 KABR 161115 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
615 AM CDT Wed Jul 16 2025

.KEY MESSAGES...

- Markedly cooler midweek temperatures with highs 15 to 20 degrees
  below normal today and 10 to 15 degrees below normal Thursday.

- An unsettled weather pattern returns Thursday night and continues
  through early next week.

&&

.SHORT TERM /TODAY THROUGH THURSDAY AFTERNOON/...
Issued at 412 AM CDT Wed Jul 16 2025

A sfc trough coupled with an upper trough is bringing another wave
of showers and thunderstorms into the region from the west this
morning. The NBM and about half of the hi-res CAMs dissipate this
precip over the northeastern cwa today, keeping the bulk of it
across central SD. On the other hand, the chance is non-zero given
the NSSL WRF, NAMNest and NBM 90th solutions. It will be working
against sfc high pressure building into the region from the north
and west. Mid level moisture appears to remain ample through at
least 21z to offer some support for showers. With the upper trough
and the cloud cover, temperatures will be 15 to 20 degrees below
climo averages this afternoon, topping out only in the 60s.

As the region dries out tonight with a 1022mb high directly
overhead, there could be some fog development for Thursday morning
given the light winds before 15z. Return flow begins to develop by
18z as the high slowly shifts east into MN and a warm front develops
along the southwestern SD/NE border, extending off a Rocky Mountain
low in Wyoming. High temperatures will remain 10 to 15 degrees below
normal, however.

&&

.LONG TERM /THURSDAY EVENING THROUGH TUESDAY/...
Issued at 412 AM CDT Wed Jul 16 2025

Zonal flow continues aloft as a shortwave will push west to east
along the northern CONUS/Canadian border Thursday night and Friday
with mid level winds of 40-50kts, associated with this wave,
skirting across northern SD into ND/MN during this time. This looks
to interact with the formation of a LLJ (20-30kts) over central SD,
east of a lee low, late Thursday night. This LLJ is forecasted to
track eastward over the CWA through early Friday as the lee low
tracks south and over the central Plains by Friday evening. By
Saturday morning a frontal boundary will lie to our south and a high
pressure system to our north over ND/Canada. With this setup, models
indicate the return of showers and thunderstorms mainly over north
central SD late Thursday night (NBM pops of 30-50%) with the precip
pushing eastward across the CWA through the day with the shortwave.
Ongoing chances of precip are possible over the southern to eastern
CWA Saturday morning, north of this front. CSU and NSSL machine
learning guidance both indicate a 5-15% chance of severe weather
Friday over the CWA while CIPS keeps the threat to our west.
However, surface convergence and forcing aloft looks to be pretty
subtle for anything widespread at this point.

A weak ridge moves in behind the exiting shortwave and over the
Northern Plains Saturday through early Sunday. The surface high will
push eastward and over ~MN/Ontario by early Sunday. Clusters
indicate a slight "baggy" -PNA pattern next week over the northern
CONUS with several embedded waves/pulses pushing eastward in this
ongoing zonal flow which lies north of a high/ridge that will hang
out over the southern/southeastern CONUS. This along with surface
troughs/weak lows, afternoon heating/instability, and low level
moisture will bring at least slight chances of precipitation through
the middle of next week. Low confidence on severe threat this far
out due to lack of strong winds aloft or any strong lows at the
surface forecasted at this time. The Climate Prediction Center
indicates this possible unsettled/wet period with a 45-50% chance of
above average precipitation between July 21-25 over the CWA.

Temps will continue to rebound after the cooler period with highs
overall ranging in the 70s and 80s Friday through the weekend (maybe
upper 80s to around 90 over south central SD Friday). Highs return
to around average Monday through the middle of next week ranging in
the 80s and 90s.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 613 AM CDT Wed Jul 16 2025

Terminals KABR,KATY,KPIR,KMBG

A chaotic mix of cigs is over the region this morning as showers
move through eastern and central SD. Expect all sites to improve
to VFR as high pressure builds in tonight. Can`t completely rule
out fog development toward the end of the period, but confidence
is too low to add a mention in the tafs yet.

&&

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

$$

SHORT TERM...20
LONG TERM...MMM
AVIATION...20