396 FXUS63 KIND 021355 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 955 AM EDT Mon Jun 2 2025 .KEY MESSAGES... - Hazy skies remain through tonight. Low probability of surface visibility reductions this afternoon - Warmer temperatures into the 80s through Wednesday - Periodic storm chances through the second half of the week && .FORECAST UPDATE... Issued at 955 AM EDT Mon Jun 2 2025 Thicker elevated smoke from Canadian wildfires was across Illinois and far western Indiana this morning, with thinner smoke to the east. The thicker smoke will slowly shift east into portions of central Indiana this afternoon. Nudged down sky cover east this morning based on latest satellite data, but will have the equivalent of partly cloudy skies everywhere this afternoon. Upstream obs don`t show any visibility restrictions at the surface, and models don`t have much mixing down to the surface later this afternoon. Will leave out any specific mention of smoke. Smoke will filter the sunshine which may keep temperatures a bit cooler than earlier expected. Nudged down highs a bit, but readings in the lower 80s should still occur for much of the area. && .SHORT TERM (Today and tonight)... Issued at 231 AM EDT Mon Jun 2 2025 A surface high will continue to meander eastward today, but remain close enough to the Ohio Valley to keep broad subsidence over the region. This will be further supported by a very elongated but strong ridge pushing in from the west. Moderate 850-700mb WAA within westerlies today will alter the ongoing airmass, leading to the start of above normal temperatures for central Indiana. This stretch of warmer weather will largely continue through most of the week, albeit less amplified late week due to greater cloud cover. The WAA today will largely be depleted of any moisture, keeping dew points in a similar portion despite large amounts of warming. The result will be a very dry troposphere over central Indiana today and tomorrow, with dew point depressions greater that 20C through the lowest 10km. Thus rain, and non-smoke related cloud cover is not expected today. Smoke from the Canadian wild fires will continue to remain aloft today and tonight. The total volume of smoke is expected to increase slightly today as winds shift towards the west. Still, this will be an indirect push of smoke, of which will be mixed through a larger column, and thus still minimal impacts despite greater overall volumes. This will still lead to a partly cloudy look in the skies today, with bright red sunsets/sunrises. If central Indiana were to see brief deterioration of air quality/visibility, it would likely be late in the afternoon when PBL mixing is maximized. With winds increasing slightly tonight, and WAA remaining strong out of the W/SW, overnight temperatures will feel much more summer-like, only dropping into the upper 50s by Tuesday morning. && .LONG TERM (Tuesday through Sunday)... Issued at 231 AM EDT Mon Jun 2 2025 Ridging aloft will be over the Ohio Valley on Tuesday with warmest air in a few weeks making an appearance across central Indiana for Tuesday and Wednesday. The ridge will shift east through midweek as an upper low tracking west of James Bay helps in flattening the flow aloft into the central Plains. The upper level flow will transition into a zonal regime through the end of the week as flat ridging aligns across northern Mexico and Texas east along the Gulf Coast. A frontal boundary will move into the Ohio Valley on Wednesday but become quasistationary into the early part of the weekend bringing a periodic convective threat. quasi-The front should be forced further south over the weekend before once again returning north early next week as a broad northwest flow pattern aloft develops with the ridge retrograding back towards Baja California. Tuesday through Friday Night The aforementioned upper ridge with high pressure at the surface will drift east of the area on Tuesday but remain in close enough proximity to maintain dry conditions. The approach of a frontal boundary from the west will tighten the pressure gradient Tuesday afternoon and aid in deeper boundary layer mixing of the dry airmass. The result will be the warmest daytime highs since mid May for the forecast area in the mid and upper 80s. The front will become bogged down from the Great Lakes southwest into the Missouri Valley Tuesday night as it runs into the surface ridging across the Mid Atlantic region. By Wednesday however...the boundary will inch into the region but in a weakened state as it becomes increasingly parallel to the mean flow aloft. Model soundings continue to advertise the presence of remnant dry air within the boundary layer through about 700mb that will serve as a deterrent to more widespread convective development despite modest instability by Wednesday late afternoon into the evening. Steep lapse rates will support a damaging wind threat from scattered storms and large hail will be possible as well with ample instability present within the hail growth zone. The boundary will become nearly stationary over the region with additional opportunities for convection likely focused Thursday afternoon and night then again late Friday into Friday night. Low level moisture will be more plentiful by late week with PWATs rising above 1.50 inches and combined with a series of waves aloft traversing through the zonal flow should provide an overall greater coverage to convection. Damaging winds and large hail will remain risks as the front gradually sags south into the Tennessee Valley by Saturday morning. Highs will remain in the mid and upper 80s on Wednesday then slide back to seasonable levels for Thursday and Friday in the upper 70s and lower 80s with increased clouds and convective coverage. Saturday through Sunday Model consensus continues to align on a break in the convective potential for most of the weekend as the boundary shifts south and is replaced by high pressure passing to the north. Will maintain low precip chances focused especially across southern portions of the forecast area however with the front nearby over the Tennessee Valley. A surface wave tracking out of the southern Plains will pull the boundary back north into the region by late Sunday with showers and thunderstorms likely increasing once again. Highs will remain at seasonable levels over the weekend into early next week ranging from the mid 70s to lower 80s gradually warming in the 8 to 14 day range. && .AVIATION (12Z TAF Issuance)... Issued at 630 AM EDT Mon Jun 2 2025 Impacts: - None Discussion: VFR conditions are expected through the next 24-30 hours for all of Central Indiana as surface high pressure remains the main weather influence. Winds will remain less than 10kt through tomorrow morning, with subtle changes from southerly to southwesterly through the day. Tomorrow afternoon, winds are expected to increase to 10- 12kt out of the S. There is some potential for gusts tomorrow afternoon as well. The only potential aviation concern an is a very low probability for slight visibility reductions due to smoke from Canadian Wildfires. Latest guidance keeps the thickest near surface smoke further to the west in Illinois, therefor the current expectation is for visibility to remain unrestricted, but there is enough uncertainty for a mention in the discussion. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...50 SHORT TERM...Updike LONG TERM...Ryan AVIATION...Updike