Area Forecast Discussion
Issued by NWS Sioux Falls, SD
Issued by NWS Sioux Falls, SD
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678 FXUS63 KFSD 130818 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 318 AM CDT Thu Jun 13 2024 .KEY MESSAGES... - Scattered showers and thundershowers will continue to move across the area through the early afternoon mainly north of I-90. Accumulations up to a tenth are expected for most areas with isolated pockets of up to a quarter inch possible. - Near to above normal temperatures will continue into the new week with daily highs expected to peak the upper 70s to 80s. - Confidence continues to increase in more widespread rain chances (60%-80%) returning by Saturday with periodic chances for additional rain continuing into the early parts of the next week. && .DISCUSSION... Issued at 315 AM CDT Thu Jun 13 2024 The Short Term (Today & Tonight): A slightly cooler day will be on tap for the day. Taking a look across the area, mostly clear conditions continue as most areas sitting in 60s to low 70s this morning. Looking to the northwestern portions of South Dakota, a few light to moderate showers with some embedded thunder have begun to develop along an Aberdeen to Mobridge to Buffalo line in response to a subtle shortwave moving across the state this morning. The general consensus among deterministic guidance has this developing line of showers pegged to gradually drifting southeastwards into the Hwy-14 corridor around daybreak (09-12z) and areas north of I-90 by mid-morning (12z-15z) before most of the activity exits our area by the early afternoon. While we`re not expecting widespread development with this activity, 200- 500 J/kg of MUCAPE along with ample shear aloft, could help create some heavier pockets of showers within the developing line. With this in mind, the general expectation is for up to a tenth of accumulation for most areas north of I-90 with a few isolated pockets of up to a quarter inch underneath heavier pockets of convection. Otherwise, the combination of strengthening mid-level cold air advection (CAA) and northerly to northwesterly surface winds will keep our temperatures in check for the day as highs peak in the low to mid 80s across the area. Lastly, clearer and quieter conditions will return by this afternoon as a surface high slides into our area from the northwest. With lingering CAA aloft and winds expected to decouple overnight, expect our lows to drop back into the low to upper 50s for the night. The Long Term (Friday-Wednesday): Heading into the start of the weekend, heights will continue to rise on Friday as the upper-level component of the ridge moves into the region from the west providing a temporary return to quieter conditions during the morning hours. Light and variable winds will become more southeasterly by the afternoon and increase with gusts up to 25 mph possible especially west of Hwy-81. Effective mixing and southeasterly surface winds will help keep our temperatures slightly above normal our seasonal normals as highs peak in the low to mid 80s for the day. Our attention will then pivot to the Colorado Rockies as a subtle shortwave and a mid-level trough lifts northeastwards into our area from as early as Friday afternoon through the day on Saturday bringing us our next widespread precipitation chances (60%-80%). While there are still a few lingering questions regarding the progression of the second wave, the consensus among ensemble guidance has low to medium confidence in at least an inch of QPF across portions of the area. Otherwise, expect most of the activity to exit the region by Sunday morning as quieter conditions return. Lastly, our highs will take a temporary dip into the mid 70s to low 80s by Saturday but should rebound nicely by Sunday as highs peak back in the upper 80s to low 90s. Looking into the new week, long-range deterministic guidance begins to diverge in potential solutions as Upper-level ridging strengthens over the eastern CONUS shifting our area to southwesterly flow aloft. Some deterministic guidance does show some decent potential for periodic rain chances on Monday and Wednesday. However, with variance in the placement of the inverted trough and subsequent shortwaves among long-range guidance its too early to tell how things will pan out. As a result, left the default NBM in for the extended. Lastly, temperatures will continue to trend near to above normal through Wednesday with highs expected to be largely in 80s with a few low 90s possible across northwestern IA on Monday and Tuesday. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 1031 PM CDT Wed Jun 12 2024 Scattered showers and isolated storms possible late tonight through Thursday morning, with the best chances along/north of I-90. Have added some VCSH for KHON toward daybreak, but confidence is low enough to omit from KFSD. Light, variable winds tonight could lead to patchy fog in low areas; however, uncertainty in coverage/development keeps confidence too low for inclusion at this time. Winds increase and shift northerly during the day on Thursday, when gusts around 20 knots are expected. Winds drop off again Thursday evening after sunset. Outside of aforementioned showers/storms and patchy fog (both of which could drop ceilings or visibility to MVFR or lower), VFR conditions prevail through Thursday evening. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ DISCUSSION...Gumbs AVIATION...SG