FXUS63 KFSD 161941 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 241 PM CDT Fri Oct 16 2026 .KEY MESSAGES... - Northerly winds will continue to gradually taper down this afternoon from west to east. - High (over 90%) chance of widespread frost tonight to early Saturday morning as temperatures fall into the lower to mid 30s. A Frost Advisory has been issued for central and south- central South Dakota for tonight, with a Freeze Warning elsewhere. - Breezy conditions are expected tomorrow with gusts of 25-35 mph expected, locally higher over the Buffalo Ridge. These breezy winds coupled with drier air could lead to marginally elevated fire weather concerns in the afternoon. - Mainly dry conditions and warmer temperatures return this weekend into early next week with highs back above normal. && .DISCUSSION... Issued at 225 PM CDT Fri Oct 16 2026 The last of the clouds will continue to diminish over northwest Iowa and southwest Minnesota over the hour or two, leading to plenty of sunshine across the area! This sunshine should allow most areas to reach the lower 50s for highs, and decreasingly breezy winds will make for a cool, but fairly pleasant fall evening. Winds will be decreasing due to a surface high pressure system moving across the region. These lighter winds coupled with clear skies will mean temperatures will drop rather quickly after the sun sets. By the late night hours though, the high pressure system will quickly slide eastward and allow for the return of southeasterly winds to the area. This should halt the faster cooling and allow for areas especially over south- central South Dakota to remain above freezing, though still remain cold enough for frost. Thus, a frost advisory will be in effect for these areas tonight. Farther east, do think the slight uptick in southeasterly winds will not make it in time to prevent these areas from dropping to 32 degrees or lower. Generally speaking, the farther east you go across the area tonight, the longer it will take for the slightly elevated winds to arrive and thus the colder you'll get. Though there is still some lingering uncertainty on the westward extent of the freezing temperatures, current thoughts are that clear skies, light winds, and dry air during the early overnight will lead to these areas dropping to freezing by daybreak. All that said, frost is expected across the entire area overnight. Southeasterly winds will continue to increase heading into the day tomorrow as the high pressure system slides east and a low pressure system develops off the northern Rockies. Winds won't be as strong as what we've seen this morning and this past night, but expect most areas to see gusts in the 25-35 mph range during the day on Saturday. A few gusts to 45 mph will be possible over the higher elevations of the Buffalo Ridge, but this is not expected to be widespread enough to warrant wind headlines at this time, though trends will be monitor. Another thing to monitor will be locally elevated fire weather conditions Saturday afternoon. Warmer temperatures are expected especially over south-central South Dakota, with highs in the 60s and possibly near 70. This combined with dew points well down into the 30s will lead to relative humidity values just below 30% in south-central South Dakota. Elsewhere, relative humidity values will be around 30-50% Saturday afternoon. This could all result in locally elevated fire weather concerns mainly in cured grasses and cropland. Ridging aloft builds in through the weekend, allowing for a seasonal weather pattern to return that will also continue into early next week. Sunday looks to be the better weekend day for outdoor activities with diminishing winds, sunny skies, and highs in the middle 60s. A weak upper wave will ride into the central Plains into the upper Midwest Tuesday into Tuesday night, though probabilities of measurable rainfall with this system is low (<20%) and focused near and east of I-29 according to latest LREF probabilities. After this weak system passes through, ridging builds back in aloft, and this combined with continued southerly flow will lead to even warmer temperatures by the middle of the week. Highs by Wednesday and Thursday will potentially climb into the 70s across parts of the area. The NBM is a bit more aggressive than other ensembles, though is only warmer by a few degrees comparatively speaking. Either way, forecast temperatures will likely get refined as mid week approaches as more smaller scale details come into better focus. Looking out to the end of next week, the weather pattern may turn a bit more active as guidance indicates a western trough potentially ejecting into the area, though the timing of this is where models really diverge. The broad 20-40% PoPs as highlighted by the NBM next Friday is largely in line with 16.12Z LREF, though details with this system will once again become more clear as we approach the end of next week. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1248 PM CDT Fri Oct 16 2026 VFR conditions expected through the period. Northerly winds will continue to diminish from west to east through the remainder of the afternoon, with winds turning light and variable this evening. Another push of higher winds, this time with a southeasterly direction, will move across the area from west to east heading into tomorrow morning. Winds with this second push won't be as strong as what we've seen this morning, but gusts to 20-30 kts can be expected by the end of the period. Slightly stronger wind gusts to 35 kts are also expected by the end of the period along the higher elevations of the Coteau des Prairies. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...Freeze Warning from midnight tonight to 9 AM CDT Saturday for SDZ039-040-054>056-060>062-065>071. Frost Advisory from midnight tonight to 9 AM CDT Saturday for SDZ038-050-052-053-057>059-063-064. MN...Freeze Warning from midnight tonight to 9 AM CDT Saturday for MNZ071-072-080-081-089-090-097-098. IA...Freeze Warning from midnight tonight to 9 AM CDT Saturday for IAZ001>003-012>014-020>022-031-032. NE...Freeze Warning from midnight tonight to 9 AM CDT Saturday for NEZ013-014. && $$ DISCUSSION...Samet AVIATION...Samet