


Area Forecast Discussion
Issued by NWS Aberdeen, SD
Issued by NWS Aberdeen, SD
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757 FXUS63 KABR 110003 AAA AFDABR Area Forecast Discussion...UPDATED National Weather Service Aberdeen SD 703 PM CDT Thu Jul 10 2025 .KEY MESSAGES... - Marginal risk (level 1 out of 5) for severe storms mainly across central South Dakota this afternoon and across northeast South Dakota into west central Minnesota on Friday. Hail up to an inch in diameter and thunderstorm wind gusts up to 60 mph are possible within the risk area on both days. - The potential exists for a noticeable cool-down during the middle of next week (temperatures 10 to perhaps 15 degrees below normal). && .UPDATE... Issued at 645 PM CDT Thu Jul 10 2025 The aviation discussion has been updated for the 00Z TAFS. && .DISCUSSION... Issued at 311 PM CDT Thu Jul 10 2025 Isolated storms are forming just south of the CWA, with some remnants of morning convection coming in from the west. Low level flow is southerly out ahead of a weak low, with heat index values running into the upper 80s to mid 90s. Still a lot of CIN to overcome this afternoon and there is a weak wave moving across the southern half of the state. CAMS are pretty limited in convective coverage this afternoon, owing to weak upper level support. Convection will tag along with the weak wave across the southern half of the state tonight, with a stronger wave up along the Canadian/North Dakota border for Friday. Shear increases across the norther tier of South Dakota through the day, however the CAPE is shunted all the way down towards Watertown/Brookings by early afternoon. CAMS still support convection as a possibility along the front prior to departing out of the CWA, in addition to the random smattering of convection northwest of the boundary which would feature more stable conditions in the low levels, skinny CAPE and that higher shear environment. Saturday will be fairly tepid with low humidity, with temperatures around 80 degrees as NAEFS 850mb temperatures drop to a standard deviation below climo. As this time, with the low and upper level flows out of the northwest, we will have to continually assess potential for impacts from Canadian wildfire smoke. A narrow ribbon of post frontal smoke should be noted with the system Friday, however Saturday there is broader support for elevated smoke moving overhead in the HRRR, though the bulk of near surface smoke looks to hang up over North Dakota late Friday/Saturday. The next round of heat is Sunday/Monday, under a northwest flow regime, though no real thermal anomalies noted in the 700mb/850mb temperatures fields. Low level flow is weak, with a weak surface trough stalling in the central/eastern Dakotas before washing out Sunday. For Monday, a lee low develops out west, lifts northeast and helps support a frontal passage and convection. Thus, the high uncertainty for Mondays` high temperatures, with the NBM 25th/75th range for high temperatures at 12 to 18 degrees. Current forecast for highs is also on the lower end, closer to the 25th percentile. That high uncertainty continues into Tuesday with a range of 8 to 14C, with the lower range across north central South Dakota where cooler air displacement is already established. Positive news in regards to the heat is that the 75th percentile dewpoints are only up into the low/mid 60s to not overly oppressive, though this is still probably downplayed as the corn is in full evapotranspiration mode. The cooler airmass will then dominate conditions for the middle of next week, with NAEFS 850mb temperature anomalies about a standard deviation below climo Wednesday and Thursday. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 645 PM CDT Thu Jul 10 2025 Terminals KABR,KATY,KPIR,KMBG VFR conditions will likely continue to prevail at all TAF sites this evening through the overnight hours. Cloud cover will thicken through the morning and midday hours Friday in advance of a cold front that will sweep through the area by late morning and afternoon. Winds will switch from a southerly direction to a northwesterly direction as the front passes. Showers and thunderstorms will be possible on Friday but with the potential for this activity to be widely scattered, have only included mention of this at KPIR/KMBG at this point since the activity will be there sooner than at our eastern terminals. Some light FU could be mixed in with the precipitation, but it shouldn`t be impactful to aviation operations. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...Vipond DISCUSSION...07 AVIATION...Vipond