FXUS63 KABR 190338 AAB

AFDABR



Area Forecast Discussion...UPDATED

National Weather Service Aberdeen SD

1038 PM CDT Mon Aug 18 2025



.KEY MESSAGES...



- Patchy to areas of fog will be possible early Tuesday morning 

across northeast SD and west central MN. Some fog could become 

locally dense prior to and just after sunrise.



- Dry and warmer conditions will set up through the middle of the 

week with the next round for showers and thunderstorms expected by 

later Thursday into early Friday.



&&



.UPDATE...

Issued at 612 PM CDT Mon Aug 18 2025



Made a few updates to pops this evening. Hi-res CAMs are

struggling with precip evolution so keeping low pops from James

Valley west early this evening. 



&&



.DISCUSSION...

Issued at 354 PM CDT Mon Aug 18 2025



One more round of scattered thunderstorms will affect portions of 

the forecast area for one more period before we get into a quiet 

pattern for a couple of days. As of 20Z this afternoon, a few 

isolated showers have been confined to north central SD, around the 

Mobridge area. However, vsbl satl imagery has shown a field of CU 

developing across parts of northwestern SD the first half of this 

afternoon along a sfc frontal boundary and now this CU field has 

become agitated enough to lead to scattered thunderstorm development 

north of the Faith area back to the southwest around the Black 

Hills. Increasing instability across areas of western and central SD 

with MLCAPE values up to 2000 J/kg and effective bulk shear values 

up to 45 kts has been noted and will remain the case going through 

the rest of the afternoon into the evening. Low and mid lvl lapse 

rates of 7-9 C/km is in place with the higher values just off to the 

west of our forecast area.



SPC has posted a slight risk for severe weather (level 2 of 5) for 

portions of central SD back to the west into the western portion of 

the state. A marginal risk for severe weather (level 1 of 5) has 

been issued for areas along and west of the James Valley into 

central SD for tonight. The main threats will be large hail 

initially before turning into a more damaging wind threat with time. 

Uncertainties still exist in coverage of storms across our western 

zones going through the remainder of the day. CAM solutions haven't 

been much help in this regard with timing and placement of any of 

this convection currently underway and going out in time into this 

evening. Nonetheless, best chances of any severe convection are 

likely to remain across our western zones into this evening and 

we'll have to continue to monitor trends going through the remainder 

of the afternoon.



By late this evening and overnight, the active weather should begin 

to wane and we'll be left with partly to mostly cloudy skies. Low 

stratus and fog is expected to develop again by daybreak across 

northeast SD and west central MN. Some of this fog could be locally 

dense, as it was in some areas this morning. After this burns off by 

mid morning, we will be left with a quiet stretch of weather through 

midweek. A ridge of high pressure will build and expand across the 

Rockies and High Plains during this time. This will lead to a more 

west to northwest flow aloft locally and result in warming 

temperatures through Thursday. Wednesday and Thursday look to be 

particularity hot across central SD with highs in the 90s to around 

100 degrees. The next disturbance is expected by Thursday afternoon 

into Thursday night in the form of a cold front. This will give our 

area the next chance for showers and thunderstorms. Increasing 

instability at that time is likely going to increase our potential 

for the next round of severe convection. We'll just have to keep an 

eye on trends the next couple days to get a better idea of what to 

expect by Thursday night into Friday.



&&



.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...

Issued at 1036 PM CDT Mon Aug 18 2025



Terminals KABR,KATY,KPIR,KMBG



VFR conditions will prevail at KPIR and KMBG Tuesday. KATY and

KABR will see a period of MVFR/IFR fog and stratus Tuesday morning

before improving by 16z. 



&&



.ABR WATCHES/WARNINGS/ADVISORIES...

SD...None.

MN...None.

&&



$$



UPDATE...20

DISCUSSION...Vipond

AVIATION...20