000 FXUS63 KFSD 021907 AFDFSD AREA FORECAST DISCUSSION National Weather Service Sioux Falls SD 207 PM CDT Fri Jun 2 2023 .SHORT TERM...(This Evening through Saturday) Issued at 204 PM CDT Fri Jun 2 2023 KEY MESSAGES: 1. Diurnal based thunderstorm activity will persist into the weekend, providing hit-or-miss rainfall. 2. Temperatures remain well above normal through the weekend and into next week. 3. Slightly cooler air along with another more synoptically driven rainfall risk may arrive by mid-week. 4. Severe weather risks look low for an extended period of time. ----------------------------------------------------------------------------------- THIS AFTERNOON: As expected, scattered convection quickly developed as convective temperatures were met in an environment with little inhibition. This scattered activity resides in an environment with tall and skinny CAPE profiles with upwards of 1000 J/KG. Mid- lvl lapse rates are rather poor, along with effective shear, so organized severe weather is not expected. DCAPE less than 500 J/KG, but updrafts will likely not be able to stay sustained long enough to produce any significant microburst potential. Still a few brief gusts to 40 knots may be possible. QPF will be very hit or miss. The brief longevity of a storm over one area should limit totals, but HREF PMM numbers indicate very localized 1" totals could be possible. TONIGHT: Convection should quickly begin to settle this evening with the loss of heating. Winds are expected to remain light and variable through the night. There are some short term models that hint at valley fog in the most sheltered areas. For now, given the low confidence, will not include in current forecast. SATURDAY: An upper ridge over the western Great Lakes will continue to retrograde westward heading into the weekend. Low-lvl flow begins to turn more to the east into the daytime hours. Again, the environment remains loosely capped, and we should again meet convective temps towards noon. So, much like today, scattered non- severe convection is again likely in the afternoon into early evening hours. .LONG TERM...(Saturday Night through Friday) Issued at 204 PM CDT Fri Jun 2 2023 SUNDAY: A bit more cloud cover may start the day on Sunday with some guidance hinting at a weak mid-lvl vorticity center tracking from east to west out of the Great Lakes early Sunday. However, Sunday may be much like Saturday, which was like Friday with another chance for diurnal afternoon convection. No severe weather risks, with temperatures rising into the 80s. MONDAY-THURSDAY: Medium range models are in good agreement that mid- lvl ridging will track westward and settle over North Dakota by early next week. This should result in dry conditions on Monday, with continued light winds and highs well into the 80s. A subtle piece of energy tracks again from east to west at some point during the first half of the week. 00Z/06Z model guidance brought this wave around the mid-lvl ridge late Monday into Tuesday. The 12Z guidance is much slower, holding this energy off until later in the day Tuesday. Feel the NBM guidance is a bit too fast, so have tried to lower PoPs to account for the newer and slower guidance. Generally though, we're stuck in a low-flow mid to late Summer-like pattern that will again feature a nearly daily afternoon chance of isolated to scattered afternoon convection. There may be a very brief cooldown mid-week, but temperatures are again expected to rise above normal into next weekend. && .AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon) Issued at 1202 PM CDT Fri Jun 2 2023 Diurnal showers and thunderstorms are rapidly beginning to develop in an area in increased surface convergence. This activity will continue to spread north and gradually northeast through the afternoon. Uncertainty remains on the direct impacts to the TAF sites. The diurnal activity is expected to diminish later this evening, with a scattered mid-lvl cloud deck continuing through the overnight hours. Scattered showers and thunderstorms will again begin to redevelop by late Saturday morning. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ SHORT TERM...Dux LONG TERM...Dux AVIATION...Dux