258 FXUS63 KIND 301814 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 214 PM EDT Fri Jun 30 2023 .Short Term...(This evening through Saturday) Issued at 214 PM EDT Fri Jun 30 2023 * Scattered convection this afternoon * Scattered to perhaps numerous convection tonight, some possibly strong to severe * Severe storms possible Saturday afternoon Rest of this afternoon... Mid level jet is aiding an area of showers and thunderstorms across central Illinois this afternoon. Relatively limited instability is keeping them in check. These will push east southeast across central Indiana mid to late afternoon. Instability is similar or a bit weaker here, so severe threat should continue to be low with these. Otherwise hot and humid conditions will persist. This evening... Focus will then shift to a boundary back across Missouri and southern Illinois. Convection will develop near this boundary and then move to the east. Uncertainty remains on where these will develop and this will have an impact on PoPs across the local area. Will have no higher than chance PoPs this evening, with the highest PoPs across the southwest forecast area closer to the boundary. Instability will be high enough that some severe storms will be possible, mainly across the southwest where instability will be highest. Overnight... Uncertainty remains high on how convection will then play out overnight. CAMs differ on whether an MCS will move across or convection will remain more scattered. Some upper energy moving around the upper ridge may add more forcing which would sustain/expand the evening convection. With low confidence, will go with high chance or low likely category PoPs overnight. A strong storm remains possible, but storms are expected to become more elevated which would limit the wind threat some. Locally heavy rain will remain a threat with any storm. Saturday... Convection will likely be ongoing still at the start of Saturday, but this will weaken and move east during the morning. A lull is then expected late morning through mid afternoon. A mid level trough will work with impressive CAPE and generate an MCS to the west and south of central Indiana Saturday afternoon. This will then propagate into the area late in the afternoon and continue into Saturday night. There remains timing questions with this area of storms, so will continue to monitor trends closely. Conditions are favorable for damaging winds (high DCAPE values) as the primary threat with these storms, but hail and perhaps a tornado cannot be ruled out. Heavy rain will be a threat with any storm throughout Saturday. Given the expected lull in convection, temperatures should be able to rebound into the upper 80s to lower 90s. && .Long Term...(Saturday night through Friday) Issued at 214 PM EDT Fri Jun 30 2023 Saturday Night Through Sunday. Much of the focus in the long term period will be on another round of storms for the weekend Saturday night and first frontal passage of the week on Sunday. As of now, confidence in thunderstorm chances is highest during the early overnight hours, but much of this will be dependent on how things evolve over the next 24 hours. Confidence is higher that after midnight conditions should begin to calm with another night of lows near 70. The severe threat looks fairly low during the overnight hours, but damaging wind gusts during the late evening certainly look possible with any ongoing MCS. A cold front is expected to pass through the area during the daytime hours on Sunday with scattered to numerous thunderstorms expected during the afternoon and evening hours. Confidence in storm mode remains fairly uncertain but the hodograph looks relatively straight which should eventually allow discrete cells to congeal into a somewhat organized line. The better shear remains to the south of the forecast area along the Ohio River which is where confidence is higher in damaging wind gusts. The front is currently expected to pass through during the late evening hours which will usher in a brief pattern shift before storm chances ramp back up later in the week. Monday Through Friday. The pattern will shift but remain messy through the early portions of the week with the upper level jet much weaker and thunderstorm chances being driven more by diurnal heating. Convective temperatures look to be reached Monday but a weak cap above the boundary layer will limit rain coverage but create a fairly widespread cu field with similar conditions expected for Tuesday. It remains a bit too early to have a lot of confidence in the forecast for the evening hours on Tuesday, but the pattern favors low rain chances with only very spotty thunderstorms that should wrap up by any late evening holiday activities. The next frontal system then begins to near the area late Wednesday into Thursday with more organized convection likely, but the most significant and widespread precipitation looks to occur over the Plains. After the frontal passage, quieter weather then looks to set up for the weekend but may begin as early as Friday depending on the final timing of the front. Highs through next week will generally remain seasonable but will vary from the low to upper 80s. && .Aviation...(18Z TAF Issuance) Issued at 100 PM EDT Fri Jun 30 2023 Impacts: * Scattered convection at times through the period. Low confidence in most details. Discussion: Some convection across central Illinois will continue to push east this afternoon. At the moment, the northern sites look to be the most likely impacted by this. Will watch and use VC or TEMPO as appropriate at issuance time. Confidence lowers for convection chances at the sites tonight into Saturday. Believe that the best chances tonight will be across the southern sites but cannot rule out at any site. How this convection behaves will impact convection chances on Saturday. At the moment believe the best chances will be after the 18Z TAF period. Winds will vary in direction this afternoon and tonight but will become more southwesterly on Saturday. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ Short Term...50 Long Term...White Aviation...50