


Area Forecast Discussion
Issued by NWS Sioux Falls, SD
Issued by NWS Sioux Falls, SD
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369 FXUS63 KFSD 070744 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 244 AM CDT Mon Jul 7 2025 .KEY MESSAGES... - Scattered showers and thunderstorms likely return this afternoon and evening. Some of these storms could become severe especially west of I-29 with up to 2 inch hail and wind gusts up to 70 mph wind gusts being the primary threats. - Additional chances for showers and storms will continue from late Wednesday through Friday. While the details are uncertain, a few stronger storms could develop so continue to monitor your local forecast for updates. - Seasonal temperatures will continue through Tuesday with highs mainly in the 80s. Could briefly see the return of some 90s on both Wednesday and Thursday mainly west of the James River Valley. && .DISCUSSION... Issued at 242 AM CDT Mon Jul 7 2025 TODAY & TONIGHT: A risk for stronger storms ahead! Taking a look across the area, mostly clear conditions continue this morning with a few isolated thunderstorms developing across the western portions of the state. As this developing activity continue to progress eastwards over the next several hours, it will likely outrun the better corridor of shear leading to a gradual weakening overtime. With this in mind, not expecting this activity to reach our area. From here, mostly quiet conditions will persist for the first half of the day with temperatures likely peaking in the low to mid 80s. As light and variable winds become more southerly ahead of our next system, dew points will increase into the mid to upper 60s setting the stage for our next severe weather chances. Looking aloft, could see some scattered activity develop along the lower Missouri River Valley during the late morning to early afternoon hours as pieces of vorticity associated with a weak shortwave interact with an advancing surface warm front. While this activity is not expected to be severe, the push of developing showers and potentially thunderstorms could do just enough to briefly stabilize the atmosphere across the U.S. Highway- 20 corridor ahead of our main system. Getting back to the main show, as a mid-level wave traverses the Dakotas; expect showers and thunderstorms to initially develop across western SD during the mid to late morning then gradually spread eastwards into central and southeastern SD during the afternoon to evening hours. With minimal inhibition according to soundings, developing semi-discrete thunderstorms will have access to 1500-1800 J/kg of instability and 35-45 kts of bulk shear which will lead to a few stronger storms. Give lapse rates between 6-7 deg C/km, large hail up to hen egg (2 inches) size would be the initial threat with the focus across southcentral SD. However, as developing thunderstorms congeal into linear segments and become more cold pool dominant; expect the threat to shift towards damaging winds with gusts up to 70 mph possible. With all this in mind, the best chances for stronger storms looks to be between the 4 pm-10 pm timeframe with most of the activity exiting our area around midnight. TUESDAY-THURSDAY: Looking into the rest of the week, northwesterly flow will return aloft by Tuesday as weak ridging sets up across the western CONUS. Periodic shower and thunderstorm chances will continue from the midweek onwards as a series of waves moves through the area almost daily. While there is still some uncertainty as to the severity of this activity, machine learning guidance seem to have latched on to higher probabilities around the Day 5 (12z Thu - 12z Fri) timeframe. Since SPC has portions of the northern plains outlined in a 15% Day 5, this will likely be our next time period to watch for stronger activity. Otherwise, expect temperatures to hover near to above normal with daily highs in the 80s to low 90s. THE WEEKEND: Heading into the extended period, could be an active start to the weekend as a quick mid-level wave pivots through the area on Friday promoting increased rain chances (30%-50%). However, quieter conditions will return for the rest of the weekend with temperatures hovering near to above normal. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1050 PM CDT Sun Jul 6 2025 VFR conditions are expected to prevail for the period. Winds are light and variable. Around sunrise Monday a weak wave looks to pass along and south of Highway 20. Showers and thunderstorms may form as the wave passes, possibly impacting KSUX. However, confidence in shower activity in the morning is low. Later in the early to mid afternoon a low pressure system will move into the KHON area and progress southeastward, encompassing most of the region. This round has the potential for strong to severe thunderstorms capable of producing large hail up to 2 inches in diameter, and damaging wind gusts to 70 mph. Though the chances are low, a tornado cannot be ruled. Storms will continue to progress southeastward through most of the overnight. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ DISCUSSION...05 AVIATION...AJP