


Area Forecast Discussion
Issued by NWS Sioux Falls, SD
Issued by NWS Sioux Falls, SD
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565 FXUS63 KFSD 151105 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 605 AM CDT Wed Oct 15 2025 .KEY MESSAGES... - Areas of fog, some locally dense, through mid morning. - Low shower/drizzle chances remain through today and tonight, though additional rainfall amounts will be less than a tenth of an inch through the period. - Warm and breezy on Thursday ahead of an incoming system that will bring additional showers along a cold front Thursday night into Friday. - Temperatures fall back to near seasonal averages for the upcoming weekend, with only low rain chances - mainly on Saturday. && .DISCUSSION... Issued at 340 AM CDT Wed Oct 15 2025 Seeing spotty light showers and drizzle remaining across the area very early this morning, with hi-res guidance suggesting this continuing through at least mid to late morning. The overall trend through the remainder of the day, however, will be for lessening coverage with increasing subsidence as an upper level ridge amplifies over the region. Additional rainfall amounts will average less than 0.05" - and this would mainly occur during the morning. Developing low pressure over CO will begin to usher warmer air northward through the day, and temperatures this afternoon will be 15 to 20 degrees warmer than yesterday. Highs will range from the lower to mid 60s north, to the 70s through the MO River corridor where there may be more breaks in the clouds by afternoon. Low pressure continues to deepen into western NE/SD tonight, and in an increasing surface pressure gradient southeasterly winds will begin to pick up overnight. Rainfall chances will remain low (20% or less) for the much of tonight, though may bump up a bit (30-40%) through our north and west later in the night as an elevated warm front lifts to the north and a LLJ develops through central NE and SD. It will be a milder night in response to the warm air advection with lows in the 50s to lower 60s. For Thursday through Friday, an upper level trough oriented through the Rockies lifts into the Northern Plains through the period. At the surface, the low pressure to our west lifts into ND and finally into south central Canada by Friday, pulling a cold front through our area as it does so. Out ahead of the front, a strong southerly flow will result in a breezy day on Thursday, along with temperatures climbing into the mid and upper 70s. Ensembles and deterministic models continue to indicate the better rain chances with this front occurring on Thursday evening as the main upper level low ejects northward out of the trough - tracking over the western Dakotas during this time frame and enhancing midlevel frontogenesis west of Interstate 29. Current rainfall amounts during this period are projected to average 0.2" to 0.3" west of I-29, with ensembles on the lower end of this amount. Rainfall chances may linger into Friday as the front finally sweeps through the area, though rainfall amounts will most likely be less with appreciable forcing weakening. With cold air advection behind the front, temperatures will cool slightly for Friday with highs into the 60s and lower 70s. Much cooler temperatures push into the region for the upcoming weekend as the upper level trough deepens over the Plains and Mississippi Valley through the period. Could again see some low rain chances for Saturday, with both the GFS and ECMWF showing upper level energy tracking southeastward on the backside of the trough, ending up in the Central Plains on Saturday. Temperatures for the weekend look to be in the 60s, with lows in the 30s. As we move into next week, confidence in the forecast becomes low with increasing model divergence in solutions. While the GFS would indicate an upper level ridge building back over our region, both the ECMWF and Canadian have a deepening trough through the Northern Plains for the beginning of next week. Temperatures over our area will be dependent on which solution verifies, though it does look like a drier period for Monday and Tuesday. && .AVIATION /12Z TAFS THROUGH 12Z THURSDAY/... Issued at 600 AM CDT Wed Oct 15 2025 Widespread IFR/LIFR stratus expected through at least early afternoon, with some improvement possible by late afternoon and evening. Otherwise, areas of MVFR/IFR fog will persist through mid to late morning, then improving by early afternoon. While spotty showers and drizzle will occur through the morning, chances will lessen during the afternoon into early tonight. Although cloud coverage will lessen tonight, there could still be areas of IFR ceilings. With a low level jet developing west of Interstate 29 tonight, there will be a period of LLWS at KHON overnight. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...Dense Fog Advisory until 10 AM CDT this morning for SDZ050-052- 057>059-063-064. MN...Dense Fog Advisory until 10 AM CDT this morning for MNZ071-072- 080-081-089-090-097. IA...None. NE...None. && $$ DISCUSSION...JM AVIATION...JM