764 FXUS63 KIND 291857 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 257 PM EDT Mon Jun 29 2026 .KEY MESSAGES... - Hot and humid condition expected for much of this week with multiple days in the 90s and heat indices over 100 degrees - Heat Advisory in effect this afternoon through Thursday - Thunderstorm chances will increase late week into the holiday weekend && .DISCUSSION (This evening through Monday)... Issued at 257 PM EDT Mon Jun 29 2026 Ensemble guidance is in excellent agreement showing anomalous ridging this week across the Ohio River Valley. Ensemble mean 500mb heights around 598dm are roughly 2-3 sigma above average for this time of the year. Ridging remains roughly in place through about Thursday, before gradually drifting eastward and weakening somewhat. At the surface, prolonged southerly flow will continue to allow moisture and warm air to flow northward. The warm and deeply subsident atmosphere should act to prevent shower or thunderstorm activity. Compressional heating combined with modest warm air advection is expected to result in above-normal warmth this week and likely into this weekend. High temperatures in the low to middle 90s are probable, with lows in the 70s. Additionally, dew points in the 70s will contribute to high heat indices between 100-110 all of this week. A Heat Advisory has been issued through Thursday evening. As the ridge gradually drifts eastward later this week, subsidence weakens allowing for the possibility of daytime / pop-up showers and thunderstorms beginning on Friday. Severe weather is not currently expected, since the jet stream is far to our north, but isolated downbursts can never be ruled out in low-shear situations. Guidance shows a weak cold front potentially arriving early next week, with an increased risk of showers/storms. Upper-level flow remains minimal, however, and organized severe weather does not appear likely at this time. && .AVIATION (18Z TAF Issuance)... Issued at 128 PM EDT Mon Jun 29 2026 Impacts: - Patchy ground fog possible early Tuesday morning Discussion: Marginal MVFR ceilings are lifting as temperatures rise. Cloud bases are now between 3000-3500 feet. Cumulus should ebb and flow between SCT and BKN this afternoon, dissipating around 00-02z. Cirrus should be present in some extent into tonight as well. Winds remain out of the south today around 10kt, decreasing this evening. Winds may become light enough to allow for some ground fog at the typically fog-prone terminals. Chances are low, so this will not be included in the TAFs for now. Winds become southwesterly on Tuesday after sunrise, increasing to between 5-10kt. && .IND WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 8 PM EDT Thursday for INZ021-028>031-035>049- 051>057-060>065-067>072. && $$ AVIATION...Eckhoff DISCUSSION...Eckhoff