Area Forecast Discussion
Issued by NWS Aberdeen, SD
Issued by NWS Aberdeen, SD
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182 FXUS63 KABR 151510 AAB AFDABR Area Forecast Discussion...UPDATED National Weather Service Aberdeen SD 1010 AM CDT Sun Sep 15 2024 .KEY MESSAGES... - Highs/Lows 15 to 25 degrees above normal through the first half of next week. - Next round of showers and storms tonight into early Monday (20 to 40% chance for moisture). Not expecting any severe weather with this round. - Multiple chances for precipitation will persist through most of next week. Highest chances will arrive Tuesday night and continue through midday Wednesday with a 50-80% chance for showers and storms. && .UPDATE... Issued at 1008 AM CDT Sun Sep 15 2024 Current forecast is on track, therefore no changes made at this time. && .SHORT TERM /TODAY THROUGH MONDAY AFTERNOON/... Issued at 423 AM CDT Sun Sep 15 2024 Storms continue to linger in northeast SD, with a few CAMS suggesting that convection will continue on through the morning hours with this weak southwest flow shortwave moving on into the western lakes region by about 12Z. As the upper trough over the western CONUS deepens, we see increasing heights aloft and ridging, so anticipate dry conditions despite continued mid level warm advection. 700mb temperatures increase to +9 to +10C today (was about +6C from the previous 12Z/00Z soundings), topping a standard deviation above climo. This warm air aloft translates to temperatures some 15 to 20 degrees above normal for today. While probabilities for exceeding 90 degrees is only about 20 percent across the northern tier of the state, it increases south of highway 212, peaking between 60-80 percent along and south of a line that runs from Pierre to Redfield (but that doesn`t include the higher terrain of the Sisseton hills). Recent rain, and southerly low level flow will also result in increasing humidity. Some things holding us back are that this fetch isn`t purely connected to the gulf, and with corn ET diminished as we are into mid September, so the probability of a dewpoint in the low 70s is negligible. Still NBM runs in the mid/upper 60s east river, with a gradient to the west initially, though even that washes out by Monday. Our next southwest flow shortwave lifts into western South Dakota tonight, tracking into central North Dakota. This will limit the extent/coverage of convection to mainly western and central South Dakota. The layout of 850mb temperatures Monday suggests nearly as warm as compared to Sunday, with lower probabilities for reaching 90 over towards the Redfield area in comparison to Sunday. && .LONG TERM /MONDAY EVENING THROUGH SATURDAY/... Issued at 423 AM CDT Sun Sep 15 2024 An active upper flow pattern will be the theme that carries through the majority of this period. A persistent and stubborn upper level low will remain more or less planted across the eastern CONUS this next week allowing for upper troughing across the western CONUS to take up residence. This will promote southwesterly flow aloft across our region the Northern Plains during most of this period. Periodic shortwave energy will rotate out of the upper troughs and into our region leading to frequent chances for precipitation through mid to late week. An ongoing round of showers and thunderstorm will be possible Monday night into early Tuesday, associated with one such upper wave. PoPs remain fairly limited to 20-30% across our eastern forecast area with minimal QPF expected. Guidance progs show the daytime hours on Tuesday will be mainly dry, warm and windy. Temperatures are likely to top out in the 80s to low 90s. Highest probabilities of reaching or exceeding 90 degrees are confined to zones along and west of the Missouri River, especially for locales south and west of the Pierre area. Deepening sfc low pressure across the Northern High Plains will tighten the gradient locally and lead to gusty southerly winds by Tuesday afternoon. Highest probabilities of seeing wind gusts reach or exceed 40 mph are along and east of the Missouri Valley and portions of the Glacial Lakes. The next slug of moisture will be on our doorstep Tuesday night. Another incoming wave will aid in allowing more showers and thunderstorms to develop. This wave still appear to be the one that has more substance behind it. Likely PoPs continue to be advertised with 50-80% chances across the forecast area Tuesday night through midday Wednesday. This system could drop some more widespread rainfall across the area. Highest probabilities(50-80%) of seeing at least a quarter of an inch or more in a 24-hr period ending 7PM Wednesday are bounded by an area west of US Hwy 281 and south of US Hwy 12. The remainder of the period will continue to feature more of the same...on and off again chances for showers and thunderstorms. Difficult to time out the next succession of upper waves to roll through the region. We`ll continue to advertise an increase in PoPs of about 30-50% from the latter half of Thursday through Saturday. Temperatures will cool back just a bit for the end of the work week but still above normal readings can be expected to continue. We might finally get back closer to normal by late in the period when a cold front finally sweeps through the region cooler temperatures back closer to normal. && .AVIATION /12Z TAFS THROUGH 12Z MONDAY/... Issued at 640 AM CDT Sun Sep 15 2024 Terminals KABR,KATY,KPIR,KMBG VFR conditions are expected at all 4 TAF sites through this next 24 hour forecast period. Gusty southerly winds will be possible at KABR/KATY terminals mid morning through the afternoon. Mid level clouds will begin to increase across the west at KPIR/KMBG by the end of the period as the next wave of precip develops west of the region. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...Parkin SHORT TERM...Connelly LONG TERM...Vipond AVIATION...Vipond