FXUS63 KABR 272359 AFDABR Area Forecast Discussion National Weather Service Aberdeen SD 659 PM CDT Mon Oct 27 2025 .KEY MESSAGES... - Greatest rain chances shift to far northeast South Dakota and west central Minnesota from this afternoon through Tuesday night, with the highest chances (50-80 percent) tonight and (30-65 percent) Tuesday. Rainfall amounts are expected to be around a quarter of an inch or less. && .UPDATE... Issued at 659 PM CDT Mon Oct 27 2025 The cold front, with a line of showers and a few embedded thunderstorms stretches from central McPherson and Edmunds counties down through Faulk, Hand, and Buffalo Counties at 00Z Tuesday. This boundary will continue to slide east through the night, and reside over far eastern SD from 05-09Z. Winds will only slowly diminish through the evening as they turn out of the northwest, and increase over central SD overnight as the pressure gradient tightens. The ongoing forecast looks reasonable, and small adjustments can be expected to match up with the changing chances of precipitation as the main band shifts east. && .DISCUSSION... Issued at 231 PM CDT Mon Oct 27 2025 At 2 PM CDT, skies are mostly cloudy and there is isolated to scattered coverage of rain/rain showers over the CWA. Watching a line of CU developing over central/north central South Dakota along a cold frontal boundary, where temperatures have warmed into the mid 50s to low 60s. Elsewhere, temperatures are in the 50s. Winds out ahead of a cold front, draped across Corson/Dewey Counties, are out of the south at 15 to 30 mph with gusts occasionally up to 40 mph. Behind the front, winds are from the northwest. The cold front/showers will continue to move/develop eastward into northeast South Dakota and west central Minnesota this evening. CAPE analyzed at generally less than 500J/kg and low to moderate deep layer shear around 25-40knots across portions of central into south central South Dakota. Despite decent low level lapse rates and more than adequate surface vorticity, not really expecting much in the way of convective threats other than perhaps a couple of lightning strikes. As low pressure begins to develop/deepen over Nebraska/Iowa late tonight into Tuesday, the cold front that works into west central Minnesota will stall out/transition to an inverted surface trough. Deformation zone/TROWAl-forced precipitation chances will linger Tuesday into Tuesday evening mainly over western Minnesota, including across the far eastern edge of the CWA. As the surface low of this system deepens, the pressure gradient increases as far north/west as this CWA, allowing for northwest winds of 15 to 30 mph with gusts up to 40 mph to develop Tuesday afternoon through Tuesday night. Beyond that, clusters analysis reveals a positive PNA pattern is, by and large, the driving influence in weather conditions around here (northwest flow aloft) from Wednesday through next Monday, give or take a couple of fast-moving clipper lows navigating the northern plains. Much of the thermal advection pattern between Wednesday and next Monday is a see-saw battle between post cold-frontal low level CAA influence and return flow low level WAA push-back. For now, the ensemble-powered temperature forecast does not show much in the way of large temperature swings, maintaining highs in the upper 40s to mid 50s for much of the forecast period. && .AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/... Issued at 659 PM CDT Mon Oct 27 2025 Terminals KABR,KATY,KPIR,KMBG Mainly MVFR ceilings are anticipated over the first couple of hours at MBG/PIR, with a longer presence at ABR and ATY as the north to south oriented cold front just west of ABR moves east and switches winds out of the northwest by 05Z at ABR and 08Z at ATY. The slowest return to VFR conditions is expected at ATY, which may not happen until 22Z Tuesday. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...06 DISCUSSION...10 AVIATION...06