000 FXUS63 KFSD 162254 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 554 PM CDT Thu May 16 2024 .KEY MESSAGES... - Well above normal temperatures will end the week. Moderate to high confidence (80-90%) in widespread highs in the 80s on Friday. Highs in the 80s will likely be limited to parts of northwest IA on Saturday with the incoming cold front. - Sunday afternoon into Tuesday starting to look more active with the potential for some locally heavy rain and severe weather possible. && .DISCUSSION... Issued at 153 PM CDT Thu May 16 2024 Model soundings indicate very weak surface based instability later this afternoon in central SD. If something could develop wind gusts of 30-40 mph would be possible, but chances of development are very low. A few stray showers could develop near highway 14 later tonight as some weak energy moves through northern SD which increases mid level warm advection, but again chances are very low. Otherwise. a ridge of high pressure at the surface will drift east tonight with southerly flow gradually increasing. This should allow for some mild lows with most locations falling to 50 to 55 overnight. Parts of northwest IA could slip into the upper 40s as the southerly flow sets up there latest. As west southwest flow increases just north of the area very warm air will build into the region which will set up a hot Friday. Highs should exceed 80 everywhere and even a chance to touch 90 in central SD. Instability will increase across the area ahead of this incoming increasing flow and deepening trough to the west. Overall everywhere looks pretty capped with some weakness noted in central SD. More than likely will need to get some development to the west of the area and have it propagate into central SD in the evening. For now the severe weather threat looks very isolated with mainly wind to worry about. Likely just a bit too much dry air to overcome. Friday night into Saturday a cool front will sweep through the area. Very mild air will be in place ahead of this front and if just slow enough lows will mostly be in the 60s east of the James River. Precipitation chances will be spotty and light. Saturday should be dry and seasonal with highs in the 70s but gusty northwest winds behind the front, likely gusting to around 30 mph. Saturday night into Sunday will see a fairly strong right entrance region of the upper level jet move across the Northern Plains as a strengthening southern stream upper level jet moves into the Central Plains. This upper level energy will bring stronger southwest flow aloft and a fairly strong mid level wave into the area. The main questions for severe potential will be the timing of the wave, with many of the current projections swinging energy into the area on Sunday morning, with a trailing wave moving through during the afternoon and evening. The morning wave will be fighting low and mid level dry air with an EML that is only moderately unstable. This should support mainly scattered showers and isolated thunderstorms. Obviously this is far enough out the smaller details are still up in the air. A look at the soundings suggests the potential for 1000- 1500 J/kg CAPE along with weak to moderate shear late Sunday afternoon and evening. With some deeper moisture surging in on Sunday afternoon, then a cold front expected to dive southeast on Monday we could see some potential for heavy rain and isolated severe storms both Sunday night and Monday. Some of the latest model information is slowing things a bit and bringing an increased threat for rain and thunderstorms behind this front Monday night into Tuesday, so still some concerns still up in the air during this time. Regardless a good chance for widespread rainfall and thunderstorms with some pockets of heavy rain and isolated severe Sunday night into Tuesday. Some agreement that the main piece of energy will move through on Tuesday with temperatures settling back to around normal Tuesday into Thursday with lower chances for showers and storms Wednesday and Thursday. && .AVIATION /00Z TAFS THROUGH 00Z SATURDAY/... Issued at 552 PM CDT Thu May 16 2024 VFR conditions expected through the TAF period. Westerly component winds will become light this evening, then increase out of the south by Friday morning - gusting around 20 kts by Friday afternoon. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ DISCUSSION...08 AVIATION...JM