Area Forecast Discussion
Issued by NWS Aberdeen, SD
Issued by NWS Aberdeen, SD
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682 FXUS63 KABR 030157 AAB AFDABR Area Forecast Discussion...UPDATED National Weather Service Aberdeen SD 857 PM CDT Thu May 2 2024 .KEY MESSAGES... - Initial round of rain ending, with more pop up summertime like showers developing over central SD through 00Z and transitioning to northeastern SD before ending early this evening. Hazards from these pop up showers would be lightning and small hail. - Dry weather expected Friday through the weekend for north central SD. However, there is a 40-60% chance of rain over south central to northeastern SD and western MN mainly Friday afternoon through Friday night. - A much larger system looks to affect the region on Monday, with widespread moderate rainfall. The threat for severe weather still appears low at this time (higher across NE/KS/OK), but we will continue to monitor trends. && .UPDATE... Issued at 846 PM CDT Thu May 2 2024 Diabatic heating earlier this afternoon generated scattered shower/thunderstorm coverage across the CWA that is winding down now. Once these remaining showers dissipate, the forecast area should be dry for the rest of tonight, under a partly to mostly clear sky. Will leave the low temperatures ranging mainly from the mid 30s to the low 40s in place. UPDATE Issued at 646 PM CDT Thu May 2 2024 See below for an aviation forecast discussion for the 00Z TAFs. && .SHORT TERM /THIS EVENING THROUGH FRIDAY NIGHT/... Issued at 249 PM CDT Thu May 2 2024 The 19Z surface map shows the exiting southern low over IA and a couple of merging lows over northwestern ND and north of Aberdeen to near Jamestown. The exiting lows will allow showers and weak thunderstorms to quickly end this evening. Before the drier air completely moves in, pop up showers in the daytime heating will continue. Mid level lapse rates of 7-8C/km are moving into central SD. Winds gusting 25-35mph have been common to our west, in this area of clearing. High mixing will allow for these winds to continue east. Fortunately, the better mixing diminishes when the stronger winds of around 60mph move across north central SD after 00Z. Still, stronger showers or a couple of thunderstorms will remain possible through the early evening hours, and could be capable of producing small hail. The dry weather will be short lived, as next area of low pressure shifting across the Central Plains will push a 40 to 60% chance of light rain across much of the area on Friday. Dry weather will remain over north central South Dakota. Chances for a wetting rain, rain of 0.10 inches or more, during the day Friday are less than 10 percent for all but south central South Dakota. The strongest winds Friday will be closer to the exiting surface low, with gusts north of Highway 12 of 25 to 30 mph through much of the day. Friday night will feature exiting rain showers over our eastern to southeastern counties, with a clearing sky. Temperatures west of the James River will fall into the lower 30s by daybreak Saturday. The 25-75th percentiles for temperatures are between 31 and 35F for western Corson County (where temperatures are expected to be the lowest). && .LONG TERM /SATURDAY THROUGH THURSDAY/... Issued at 249 PM CDT Thu May 2 2024 The long term portion of the forecast begins on Saturday with a surface high pressure and broad upper level trough over the region. High temperatures may warm to within a few degrees of average. The surface high pressure shift eastward on Sunday with increasing southerly winds across the plain states. The southerly winds will also bring warmer temps in the area with highs reaching the 60s and 70s for most locations. The NBM is showing wind gusts exceeding 30 knots Sunday afternoon, mainly along and west of Highway 83. Higher gusts exceeding 45 knots will be possible in Corson and Dewey Counties. The NBM has a 70-85% chance of winds exceeding 45 knots in north central SD. However, half km winds off the GFS is lower, and so is the grand ensemble. Thus, will blend in lower wind gusts Sunday afternoon. An upper level trough and associated surface low pressure system will cross the region on Monday, bringing a 55-80 percent chance of showers. Low level moisture and increasing instability does move into the CWA ahead of the frontal boundary with the NBM showing a 20 to 50 percent chance surface CAPE exceeding 500 J/kg. The probability of seeing 1K J/kg is non-existence over the CWA, and even for much of SD. Even with the limited instability, excellent deep layer and low level wind shear may produce some storms to monitor on Monday. Beyond Monday, the upper level trough remains near the northern plains with periods of showers in each forecast period next week. Temperatures next week will favor near average. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 646 PM CDT Thu May 2 2024 Terminals KABR,KATY,KPIR,KMBG Most of the TAF valid period at all four terminals is forecast to be VFR. Through ~03-04Z, will be dealing with isolated (<25%) to widely scattered (25-45%) showers and thunderstorms over the region. Some of this convection could contain gusty winds up to 40-50 mph and/or small hail (<0.75in). && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...Dorn SHORT TERM...KF LONG TERM...SD AVIATION...Dorn