Watertown, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

306
FXUS63 KABR 102345 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
645 PM CDT Tue Jun 10 2025

.KEY MESSAGES...

- Elevated smoke remains over the region with a return of near
  surface smoke on Wednesday.

- An unsettled weather pattern returns with shower and
  thunderstorm chances through the weekend with the highest
  chances (60 to 85%) Thursday evening through Friday morning.

- There is a marginal risk (1 out of 5) for severe thunderstorms
  Thursday afternoon and evening along and east of a line from
  Chamberlain to Sisseton.

&&

.UPDATE...
Issued at 634 PM CDT Tue Jun 10 2025

Aviation discussion updated below for the 00Z TAFs.

&&

.DISCUSSION...
Issued at 316 PM CDT Tue Jun 10 2025

As of 230pm, scattered mid to high clouds are filtering in over
portions of northern to northeastern SD and west central MN, from
the northwest. Otherwise with the ongoing smoke aloft, the sky
remains milky. Temperature range in the mid to upper 80s to the
lower 90s with overall west to southwest flow at the surface. Main
concerns for the forecast package will be ongoing smoke and the
unsettled weather pattern, leading to several rounds of
precipitation through the weekend into early next week.

Northwest flow aloft continues over the Northern Plains on the
downstream side of a ridge with winds turning more zonal early
Wednesday morning. The bulk of the wildfires are now in British
Columbia and Alberta and with this west/northwest flow aloft, HRRR
Smoke model indicates ongoing smoke possible over the area aloft
through at least Wednesday. At the surface a weak low will be over
west central SD with its cold front sprawled horizontally from here
through east central SD by 00Z. This low and front will continue to
push southward through the overnight. Behind this front, HRRR
indicates the return of near surface smoke moving in over the
northern potions of SD tonight and spreading southward/southwestward
over the CWA into Wednesday. This front becomes a stationary front
over the SD/NE border Wednesday morning and parks itself over this
area through early Thursday morning. During this time, its low will
be centered over west central NE. As the low moves across the
boundary Thursday, the now warm front then lifts north with the warm
sector over east central to southeastern SD/southwestern MN by
Thursday evening. The cold front then moves through with the center
of the low over MN/SD/IA border by 12Z Friday. Additionally, a fast
moving shortwave will move in from the west, pushing east then
northeast over the Northern Plains through Thursday night/early
Friday with a ridge building in behind it.

CAMs do show the possibility of spotty precip moving in from the
west/northwest this evening and continuing through the night along
and behind the front, however, location and timing does differ
between the models. Also, there is a differences in intensity as
HRRR is the most aggressive with some of the precip (30-45dbz)
whereas a few of the others models only show light showers. So
confidence is low on exact outcome. NBM pops seemed to be way too
high compared to what the CAMs are showing, so I did bump down the
maxes` a bit with pops up to 30 percent. This may need to be
adjusted closer to time. HREF indicates weak instability (under 1000
j/kg) through this evening, however, probability of dbz>40,
MUCAPE>50 is about 10-30%. With the front to our south Wednesday
morning and shortwave activity aloft, additional showers and
thunderstorms will develop through Wednesday night with overall pops
of 30-65% with the highest over east central SD Wednesday evening.
There really will not be much in the way of instability or shear (as
the strongest of this remains south of the CWA) so this should
mainly just be elevated showers/general tstorms.

With the shortwave moving in from the west along with this ongoing
stationary/warm boundary (lifting a tad north) and an increase in
winds aloft (40-50kts), chances of precip continue Thursday through
early Friday with widespread pops of 50-85%, highest along and east
of the James River Thursday evening into early Friday where this
boundary lies/near center of the low. With this setup, some of the
storms could become severe towards Thursday afternoon and evening as
dew points will range in the upper 50s to around 60 and some
instability, with the bulk of it lying further south. The SPC has
highlighted a marginal risk (1/5) for severe storms mainly east of a
line from Chamberlain to Watertown SD. With an increase in moisture
EC EFI indicating 0.5 to 0.6 and shift of tails of zero, but this
looks to mainly be over southeastern SD. NBM probability of 24hr
rainfall>0.50", ending Friday 12Z is 50-65% east of the James River
and highest over our southeastern CWA.

Looking beyond this time, Clusters agree on the ridge remaining over
the central CONUS through the weekend as a trough sits south over a
persistent low spinning over the northern Pacific/western Canada
coast. This trough looks to move in onshore and over the western
CONUS early next week. With this setup, winds will be zonal through
the weekend (which could continue to bring in smoke aloft) turning
southwesterly early next week. This leads to an ongoing unsettled
weather pattern as we have ongoing chances of precipitation this
weekend through early next week per several shortwaves and its
surface systems passing over the area.

Cooler temps expected for Wednesday ranging in the 70s behind this
cold front. A cooler air mass will sit over the area with highs in
the upper 60s to 70s Thursday through Friday. Temps look to warm up
gradually through the weekend with highs back in the 80s to near 90
by Sunday.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 634 PM CDT Tue Jun 10 2025

Terminals KABR,KATY,KPIR,KMBG

Smoke (FU) aloft and at the surface is expected through the TAF
period. Smoke concentration starting off at 00Z is not that high,
but is forecast to increase during the overnight hours. Included
mention of 6SM FU at times at the TAF sites through the period,
but there is potential for VSBY to drop to MVFR. Otherwise, VFR
conditions are forecast, with the potential for widely scattered
-SHRA overnight into Wednesday. PROB30 was used to handle this.

&&

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

$$

UPDATE...TMT
DISCUSSION...MMM
AVIATION...TMT