


Area Forecast Discussion
Issued by NWS Indianapolis, IN
Issued by NWS Indianapolis, IN
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062 FXUS63 KIND 280707 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 307 AM EDT Sat Jun 28 2025 .KEY MESSAGES... - Slightly less hot today, though still quite humid - Scattered daily afternoon showers/t-storms through at least Monday, isolated strong wind gusts are possible as well as localized flooding - Drier and slightly cooler conditions expected for the middle of next week && .SHORT TERM (Today and tonight)... Issued at 307 AM EDT Sat Jun 28 2025 The presence of a weak and diffuse surface boundary, not to mention myriad remnant outflow boundaries from recent rounds of convection, in the background setting of a continued warm and very moist airmass, will set the stage today for additional thunderstorms, primarily over the southern third to half of the area near and after peak heating. Very weak flow throughout the depth of the troposphere will result in slow storm motions, and minimal to no severe threat beyond the outside shot at a localized downburst owing to the minimal shear. Thus, the primary hazards will be the typical lightning concerns, as well as locally heavy rainfall and isolated flash flood concerns, given the slow storms and precipitable water values approaching 2 inches, near the top end of climatology for what is already nearing the peak PWAT time of year as it is. Despite the ample instability, coverage should be limited to isolated to scattered at best with a lack of large scale forcing for ascent or other significant forcing mechanisms beyond the aforementioned weak boundaries. Temperatures will still be warm, and conditions quite humid, but not quite as oppressive as much of this week. Expect most areas to top out mid to upper 80s, perhaps a few areas near 90, which, combined with dewpoints largely in the upper 60s to low 70s will produce peak heat index values in the mid 90s, about 5-10 degrees cooler than much of the week. Lows tonight will drop back to near dewpoints in the upper 60s to low 70s, and depending upon degree of clearing, may set the stage for some patchy dense fog, though this will depend heavily on amount of debris cloudiness from convective activity later today. Winds will likely be light enough to support at least some light fog. && .LONG TERM (Sunday through Friday)... Issued at 307 AM EDT Sat Jun 28 2025 Sunday through Monday night.. Expect elevated rain chances early in the period as a shortwave trough and associated cold front approach. Gradually strengthening southerly flow ahead of the system will help push deeper moisture northward on Sunday. This combined with daytime heating should promote scattered diurnal convection. NBM POPs appear too high during the day given weak overall forcing so decided to lower rain chances. Still expect rain chances around 20-40% over the north half of central Indiana and 40-50% across the south. POPs may need to be lowered even more in future updates depending on model trends. Stronger dynamics from the upper wave moving in will then likely lead to more widespread convection late Sunday night into Monday. Deep-layer shear is weak, but a few strong storms with gusty winds cannot be completely ruled out Monday as moderate destabilization occurs. The system should then begin to shift east Monday night with rain chances diminishing. Expect highs to generally be in the upper 80s to near 90F over the weekend and mid-upper 80s on Monday. Tuesday onward... Mostly quiet weather conditions are expected Tuesday through Thursday as weak high pressure settles in. In addition to a drier forecast, slightly cooler temperatures in the mid 80s are expected Tuesday and Wednesday. Dewpoints falling into the 60s should also feel more comfortable compared to the very humid conditions over the past week. Ensemble guidance suggest moisture begins to stream back into the region ahead of another system towards the end of the week. This will lead to increasing rain chances, but increasing model spread leads to higher uncertainty in exact timing and details. && .AVIATION (06Z TAF Issuance)... Issued at 127 AM EDT Sat Jun 28 2025 Impacts: - Spotty MVFR conditions possible just before daybreak - Isolated to scattered thunderstorms again Saturday, primarily south Discussion: Ample low level moisture in the presence of a weak boundary may promote development of MVFR conditions, either ceilings or visibilities, just before to near daybreak this morning. This is fairly uncertain, and will carry SCT020 decks all but LAF, where skies are a bit clearer, and fog may develop. Will carry a TEMPO fog group there. Once these conditions, if any, dissipate, expect scattered to broken VFR cumulus, with convection potentially developing over the southern third to half of the area. Will carry a PROB30 thunder group at BMG, but IND/HUF may not be entirely out of the woods. Light winds and eventually clearing skies overnight tomorrow night may promote fog development, but this is far too uncertain for a mention at this time. && .IND WATCHES/WARNINGS/ADVISORIES...None. && $$ SHORT TERM...Nield LONG TERM...Melo AVIATION...Nield