Isabel, South Dakota Weather Forecast Discussion

058
FXUS63 KABR 191713 AAC
AFDABR
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1213 PM CDT Fri Sep 19 2025
.KEY MESSAGES...
- Light to moderate rain tracking over the same area for an extended
period may result in ponding water, and may result in localized
flooding concerns through this evening.
- Additional rainfall amounts through Saturday morning generally
between a half and 1 inch over northeast SD into west central MN.
- Temperatures are expected to warm up through the weekend, with
high temperatures reaching the upper 70s on Sunday, 5-10 degrees
above normal. Highs will become near-normal by the middle of next
week.
&&
.UPDATE...
Issued at 1212 PM CDT Fri Sep 19 2025
Aviation discussion has been updated in accordance with the 18Z
TAF issuance.
UPDATE Issued at 1011 AM CDT Fri Sep 19 2025
Fog is dissipating this morning, and visibilities are improving
across northeastern South Dakota. Still expecting the slow-moving
low pressure center to slide east today, but showers will persist
through tonight, with some lingering chances for light rain into
tomorrow. Areas with extended temporal coverage of showers could
see as much as an inch to an inch and a half through Saturday
evening.
UPDATE Issued at 640 AM CDT Fri Sep 19 2025
Aviation discussion updated below for the 12Z TAFs.
&&
.SHORT TERM /TODAY THROUGH SATURDAY AFTERNOON/...
Issued at 418 AM CDT Fri Sep 19 2025
Low pressure is centered over eastern SD early this morning, with
areas of rainfall continuing to rotate around the low. Most of the
rainfall overnight has been over central SD, with increases in areal
coverage of showers now over the far eastern CWA along and east of I-
29. Also seeing areas of fog across the eastern CWA under the
surface low where winds are lightest, especially in the James River
valley. Visibility is around one-half mile or below at times. Will
continue to monitor obs and web cams for potential headlines
concerning fog.
For the remainder of the day, expect very little movement with the
low pressure as areas of showers continue to rotate across the
region. We likely won`t see a noteworthy decrease in areal coverage
of showers until late tonight into Saturday when lowering rainfall
chances shift to the eastern CWA. It appears the heaviest of rain
has likely already fallen over the area, but continued
light/moderate rain today/tonight will add on to the multi-day
totals that are now over 2 inches for quite a few areas. That said,
at least central SD appears to be out of the threat for additional
heavy rainfall as the focus today shifts east a bit where amounts up
to an inch are possible over the far eastern CWA through Saturday
morning. There may be additional areas that start to see issues with
standing/ponding water in low-lying areas.
&&
.LONG TERM /SATURDAY EVENING THROUGH THURSDAY/...
Issued at 418 AM CDT Fri Sep 19 2025
While the upper and surface low pressure starts to move out of
northeastern SD during the weekend, it takes until Sunday evening
for the models to show the upper-level trough fully out of
northeastern SD and the surface low firmly over MN. With the surface
low moving to the east, precipitation chances decrease over
northeast SD Sunday morning, keeping Sunday mostly dry.
The next chance for precipitation starts to move into central SD
Monday morning as an area of lower pressure move over western SD
when an upper-level shortwave moves over the state. The models are
showing a boundary over southern SD/northern NE, with varying
locations in the models. By late Monday afternoon into the evening,
the NBM shows the boundary tracking north slightly, pushing showers
and storms moving into south central SD and then moving north
through the evening and into Tuesday. Despite this, some other
models keep the boundary and showers/storms out of central and
northeastern SD. This leads to lower chances (20-35%) for rain
though the day Tuesday at this time. During Tuesday night, an upper-
level ridge and some higher pressure start to move into central and
northeastern SD, which will help to keep the area dry for a couple
of days.
Saturday evening, some warm air starts to advect into central and
eastern SD. While it is not a lot nor very strong WAA, temperatures
start to warm Sunday through Tuesday with highs in the low to upper
70s, which is 5-10 degrees warmer than normal for this time of the
year. Wednesday, temperatures return to normal, in the upper 60s to
mid 70s. One thing to note is that the low temperatures from Sunday
through Friday will be 5-15 degrees warmer than normal for this time
of the year, in the low 50s. So, sadly the crisp cool fall evenings
will not be arriving for a little bit.
&&
.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1212 PM CDT Fri Sep 19 2025
Terminals KABR,KATY,KPIR,KMBG
Low pressure center continues to bring low clouds and rain showers
to the forecast area today. Areal coverage of showers is mainly over
northeastern South Dakota, and is expected to remain that way
through the day today. As the low pressure shifts off to the east,
areal coverage will decrease and showers will become more scattered
beginning late this evening through the rest of the TAF period.
Confidence is low on location, but PROB30s have been included in the
KABR and KATY TAFs to cover the potential. Ceilings are expected to
somewhat variable again today, mainly staying at MVFR levels while
occasionally dipping to IFR under rain showers.
There is once again a signal for fog tomorrow morning, mainly over
northeastern South Dakota. Visibility is expected to drop to between
1 to 3 miles at times, but there may be local pockets of less than 1
mile. Coverage is expected to be similar to what was observed this
morning, which is somewhat broad coverage of lighter fog combined
with localized pockets of denser fog.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
UPDATE...BC
SHORT TERM...TMT
LONG TERM...12
AVIATION...BC

NWS ABR Office Area Forecast Discussion