James, South Dakota Weather Forecast Discussion

935
FXUS63 KABR 250827
AFDABR
Area Forecast Discussion
National Weather Service Aberdeen SD
327 AM CDT Thu Sep 25 2025
.KEY MESSAGES...
- Patchy fog is possible early this morning over portions of
east central SD.
- A prolonged period of dry, warm, and windy conditions Sunday
through at least Wednesday. Temperatures in the 70s and 80s (5 to 15
degrees above normal), with southerly wind gusts 30-35 mph, or
potentially higher.
&&
.SHORT TERM /TODAY THROUGH FRIDAY AFTERNOON/...
Issued at 326 AM CDT Thu Sep 25 2025
There is some areas of patchy fog developing over east central SD
this morning, which should dissipate after the sun rises. During the
morning and though the day today, an upper-level ridge will be
moving over SD. At the surface, an area of higher pressure starts to
move out of SD during the evening. While this change brings a wind
shift to central and northeastern SD today, from the southwest to
the north, there still will not be any chances for rain today. With
warm air advecting into central and eastern SD, temperatures look to
warm today and into tomorrow to be 10 to 15 degrees warmer than
normal for this time of the year. High temperatures will be in the
upper 70s to mid 80s today and warm into the low to upper 80s on
Friday. To better show this in the grids, a blend of the NBM and
NBM90th was used for max temperatures for both days.
An upper-level shortwave over ID starts to move east towards SD
today and Friday, with models showing the shortwave reaching western
SD Friday afternoon. At the surface, an area of lower pressure
develops over southwestern SD overnight into Friday morning, with an
attached cold front to the north. This surface low pressure moves
east through the day Friday and will then move over central SD by
the afternoon and northeastern SD during the evening. Much drier low
level air over the area in front of the cold front helps to keep
showers from forming over central and northeastern SD Friday. One
thing to note, is that the tightening pressure gradient between the
high pressure to the east and the low pressure will increase winds
aloft Friday. The higher lapse rates in the afternoon and evening
will likely help to get these stronger winds aloft to the surface,
increasing the wind speeds and gusts. To more accurately represent
the winds and gusts, which could get between 20-30 kts during the
afternoon, a blend of the NBM and NBM90th was used for early Friday
afternoon into the evening.
&&
.LONG TERM /FRIDAY EVENING THROUGH WEDNESDAY/...
Issued at 326 AM CDT Thu Sep 25 2025
On Saturday we`ll be in the post-cold frontal air mass, which will
mean cooler highs in the 70s compared to the widespread 80s on
Friday. Surface high pressure will be moving eastward across the
region as well, so looking at light winds on Saturday.
Sunday through the middle of next week the upper level pattern will
begin to form a tough along the northwestern coast of the U.S. A
persistent broad surface trough looks to set up across MT/WY into
the far western Dakotas, which will tighten the pressure gradient
across the CWA. This pattern looks to remain established for several
days, perhaps through Thursday. This also means persistent windy
conditions (south winds) and warm air being pumped northward into
the Northern Plains. Highs likely to be 5 to as much as 15 degrees
above normal at times, with readings in the upper 70s to mid 80s.
Inherited NBM winds feature southerly gusts 30-35 mph Mon-Wed. It`s
entirely possible these winds are too low, and may need to blend in
some NBM90 speeds once the time approaches. Speaking of NBM90 winds,
gusts there are closer to 40-45 mph, so something to monitor in the
coming days.
&&
.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1203 AM CDT Thu Sep 25 2025
Terminals KABR,KATY,KPIR,KMBG
VFR conditions will continue for the majority of the period. Fog
will again be a concern at both ABR and ATY from around daybreak
to 14-16Z. Forecast guidance has less fog at ABR, and have opted
to keep the potential at 5SM. ATY will continue to have a higher
chance of fog, with visibility falling at or potentially below 2SM
at times (TEMPO) from 12-14Z Thursday. Less fog is expected
compared to Wednesday morning.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
SHORT TERM...12
LONG TERM...TMT
AVIATION...06

NWS ABR Office Area Forecast Discussion