Area Forecast Discussion
Issued by NWS Sioux Falls, SD
Issued by NWS Sioux Falls, SD
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710 FXUS63 KFSD 091044 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 544 AM CDT Sun Jun 9 2024 .KEY MESSAGES... - Pleasant conditions prevail today and Monday with seasonable temperatures and breezy afternoons for portions of the area. - Periodic chances for showers and storms return Monday evening and continue through much of the week. - Uncertain severe weather risks focused mainly on Wednesday afternoon and evening. - Temperatures rise by the middle of the week above normal. High probabilities (>80%) of highs above 80 degrees, with low probabilities (up to 40%) of highs at or above 90 degrees by Wednesday. && .DISCUSSION... Issued at 335 AM CDT Sun Jun 9 2024 A quiet day is in store across the area as surface high pressure over west central Canada builds southward into the Northern Plains. In spite of weak cold air advection into the area as a mid/upper level trough swings southward through the Mississippi valley, deeper mixing will allow for warming temperatures for today. Look for highs in the mid 70s to lower 80s. The stronger winds aloft will reside through MN and IA where cold air advection is most notable, and with the deep mixing it will be a breezy day east of Interstate 29 - with sustained winds of 20-25 mph/gusts of 25 to 35 mph in the afternoon. Winds quickly die off this evening, and with continuing cold air advection lows will fall to below normal levels for this time of year - in the upper 40s to lower 50s. Monday will start off dry with the surface ridge axis over our area moving into the Mississippi Valley during the day. At the same time, a surface trough will deepen over the western portions of SD and NE. This will produce breezy conditions west of Interstate 29 during the afternoon - this as the surface pressure gradient steepens and a low level jet develops through central SD. With surface winds transitioning to southeasterly during the day behind the exiting high, temperatures will be a little warmer - mostly upper 70s to lower 80s. Shower and thunderstorm chances then increase for Monday night into early Tuesday as the aforementioned surface trough/frontal boundary to our west pushes eastward through the area. Models are in pretty decent agreement on timing, with the front pushing into our western CWA very early Tuesday morning, then exiting to the east around by 21Z on Tuesday. Severe chances look low with the system, with models indicating the better instability/shear remaining to our west on Monday evening, then the precipitation exiting our area on Tuesday before instability recovers in the afternoon. Weak cold air advection behind the system will not have much of an impact on temperatures on Tuesday as highs warm well into the 80s. With the departure of Tuesday`s trough, the upper level pattern takes on a quasi-zonal flow for midweek, before an upper level ridge builds eastward into the region for the end of the week into the weekend. It looks to remain rather unsettled through the period with periodic shower and thunderstorm chances - perhaps focused more so on Wednesday afternoon/evening and Friday night. Latest model convective parameters would suggest at least some potential for severe weather during those periods, though with model variability confidence remains on the low end. Guidance would suggest that temperatures will be above normal for mid to late week. && .AVIATION /12Z TAFS THROUGH 12Z MONDAY/... Issued at 540 AM CDT Sun Jun 9 2024 VFR conditions expected through the TAF period. Relatively light northerly winds for much of the area today, though stronger winds will reside east of Interstate 29 during the afternoon - with gusts of 25 to 30 kts over portions of southwestern MN and northwest IA. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ DISCUSSION...JM AVIATION...JM