


Area Forecast Discussion
Issued by NWS Aberdeen, SD
Issued by NWS Aberdeen, SD
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
060 FXUS63 KABR 112013 AFDABR Area Forecast Discussion National Weather Service Aberdeen SD 313 PM CDT Fri Jul 11 2025 .KEY MESSAGES... - Marginal risk (level 1 out of 5) for severe storms mainly from the James Valley eastward into west central Minnesota remains in place for this afternoon and evening. Hail up to an inch in diameter and wind gusts up to 60 mph are possible within the risk area. - Wildfire smoke will return for Saturday, both aloft and near the surface. Visibility during the early morning hours may be significantly reduced as it heads into the northern tier of South Dakota. - The potential exists for a noticeable cool-down during the middle of next week (temperatures 10 to perhaps 15 degrees below normal). && .DISCUSSION... Issued at 226 PM CDT Fri Jul 11 2025 Front has cleared the CWA, with smoke lingering though with improved visibility. Showers on the backside of the front have dropped in coverage since this morning, however down by Clear Lake we do have a cumulus field bubbling up. Still some high instability with 21Z NAM indicating about 3K j/kg MLCAPE, though that does progress out of the CWA by 00Z, and a few CAMS show a blowup over the far southeast CWA, though fewer CAMS in comparison to earlier runs have storms back this far. Shear in this area is relatively weak however. NAM BUFKIT profiles even indicate that back towards Aberdeen we could reach our convective temperature, however with lowering dewpoints and moist mid-levels, its a skinny CAPE profile, though with stronger mid level flow than in comparison to down by Watertown. Regardless, CAMS are not too impressed with the convective potential out this way despite our closer proximity to the upper level wave... though we have seen some blow ups just east of Wheaton already this afternoon. Additionally, another area of rainfall is headed in from west-river into the Pierre area. For Saturday, NBM high temps are in the 80s, and 70s over in the east. The big question is how will smoke, elevated and at the surface, impact temperatures. HRRR concentration of both near surface and elevated smoke are mainly during the first half of the day, confined to about the James valley and points east, while the RAP is a little broader and lingers overhead longer. This should knock about 3 degrees down for Aberdeen/Redfield and points east. NBM box and whisker only shows we have about a 1-3 degree range in highs for Saturday (high confidence) but does`t account for smoke. Counterpoint when it comes to temperatures Saturday, we also have a favorable mixing wind direction. Despite this, will go below the NBM 25th percentile in the eastern CWA. Zonal, west to northwesterly flow regime sets up for early next week. Either one or two weak waves (depending on model) associated with the southwest monsoon gets caught up in the stronger westerlies and is then pulled across the Northern Plains late Monday-Tuesday timeframe. A front also comes down Tuesday as high pressure moves into south central Canada. Thus, have a broad timeframe for low/moderate POPs. Machine learning/AI severe weather models are mixed with regards to severe weather potential in during this time period, with NCAR medium range convective hazard forecast highlighting Monday, while CSU and CIPS are both clear of threats. This flow regime will also result in hot conditions, though with a drier airmass despite the level of corn maturity, especially Sunday with more of a westerly wind component, with return flow Monday brining in the juicier airmass just as a front comes through to knock it back down again. Still looking forward to cooler temperatures for the middle of next week. NAEFS 850mb thermal anomalies are down to a standard deviation below climo starting 00Z Wednesday and lasts into Friday morning. Unfortunately, while the heat and humidity will be turned off for a bit, we may still have to deal with Canadian smoke. Additionally, guidance directs two waves over this cool airmass so we will need to contend with precipitation. At these timescales, confidence in either`s impacts is pretty low, but something to watch for the next few days. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1229 PM CDT Fri Jul 11 2025 Terminals KABR,KATY,KPIR,KMBG A frontal boundary has pushed across all terminals with northerly winds prevailing. Gusts exceeding 30 knots have been observed at times. Smoke has accompanied the winds, with visibility dropping to 2SM at times. The visibility should improve later this evening and through the overnight hours. However, smoke should move back into the forecast area on Saturday, possibly impacting all terminals. Of note, weak showers are occurring behind the frontal boundary with minor issues to terminals possible. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ DISCUSSION...07 AVIATION...SD