Area Forecast Discussion
Issued by NWS Northern Indiana
Issued by NWS Northern Indiana
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699 FXUS63 KIWX 150931 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 531 AM EDT Sat Jun 15 2024 .KEY MESSAGES... - Warm and dry this weekend with partly to mostly sunny skies. Highs will be in the upper 70s and low to mid 80s today, then climb into the upper 80s and low 90s Sunday. - Hot and humid conditions prevail Monday into next weekend, with highs in the 90s. Monday will be exceptionally hot, with widespread highs in the mid to upper 90s. Heat indices will range from 95 to 105 through the week. - Isolated showers and thunderstorms are possible daily next week, mainly in the afternoon and evening hours. && .DISCUSSION... Issued at 430 AM EDT Sat Jun 15 2024 All aboard the heat train from now until next weekend! High temperatures today will be in the upper 70s and low to mid 80s, then climb into the upper 80s and low 90s for Sunday. By Monday, temperatures will climb into the mid to upper 90s, with heat indices of 99 to 105. From Tuesday into next Monday, highs will be in the 90s, with locations generally along and south of US 24 seeing the majority of the mid-upper 90s. Heat indices in these areas will be around 100 degrees. While most of the event will reach heat advisory levels, the prolonged nature of the event (through at least Saturday) with heat indices around 100 degrees all week suggest a possible need for an excessive heat watch. Held off on issuing any headlines this shift per collaboration with the neighbors, as there are still questions with respect to how much moisture, cloud cover, and precipitation we can get. At the moment, think that NW OH and IN counties south of US 24 (especially further east) have the best chance for reaching excessive heat warning criteria. Outside of that, temperatures will still be in the low 90s with heat indices around 95 degrees--so those areas will still experience impacts-but just may be more likely to stay in advisory criteria. It should also be noted that we are in a moderate risk for the CPC 8- 14 day US Hazards outlook for excessive heat from June 22nd-24th (Saturday into next Monday). The slight risk goes until Wednesday the 26th. So we`re looking at a prolonged event in which impacts will become cumulative. Even with the concerns of clouds/precip outlined below, suspect we may need a heat watch for the entire area just due to the advisory criteria lasting longer than 4 consecutive days. Overnight lows will only drop into the upper 60s and 70s, which limits recovery time. Expect mostly dry conditions with variable cloud cover through the week, though there are nearly daily LOW chances for afternoon showers/storms. The tricky aspect of the forecast is that starting Monday we`ll be on the periphery of a large upper level ridge, with various shortwaves impinging on the north and west portions. With abundant moisture/heat in place, we`ll be susceptible to any of these more subtle waves, which are impossible to really pin down specifically at this point. For now, carried 20-30 percent chances, mainly in the afternoon/early evening hours of showers and storms. Expect the coverage to be quite isolated for most cases-but if the ridge does stay further east as the GFS depicts, coverage could be more scattered to numerous at times. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 528 AM EDT Sat Jun 15 2024 A large surface high pressure area will remain over east North America. Large scale subsidence with dry air in the low and mid levels should prevent clouds from forming except for some high clouds topping the upstream ridge. VFR conditions will prevail with winds around or less than 10 knots. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...MCD AVIATION...Skipper