Area Forecast Discussion
Issued by NWS Northern Indiana
Issued by NWS Northern Indiana
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979 FXUS63 KIWX 130003 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 803 PM EDT Fri Jul 12 2024 .KEY MESSAGES... * Periodic chances (20-40%) for thunderstorms Saturday night through Tuesday. There is the potential for severe storms, especially later Sunday night through Tuesday. * Hot and humid conditions are expected Sunday and Monday, dependent on storm coverage and timing. && .DISCUSSION... Issued at 133 PM EDT Fri Jul 12 2024 Broad but weakening upper trough axis positioned through wrn MI will rotate out into se ON by sunset. Residual convergent moist axis invof the tri-state line and south may yield an isolated shower or storm this aftn with continued heating/destabilization otherwise the rest of the area expected to stay dry. Return flow begins in earnest late day in response to building thermal ridge out west and developing low pressure across NE. While most cam solutions are dry tomorrow aftn will hold w/slight chc mention west and south to account for upticking theta-e ridge. Thereafter large scale pattern aloft from the nrn plains through the lakes/OH valley turns quite interesting. Substantial heating/moisture advection beneath building upper ridge across the plains portents several episodes of strong to severe convection in the coming days. How this plays out exactly in regard to timing and potential severity remains in question given mesoscale system development upstream over the Dakotas and upper midwest followed by subsequent downstream evolution and timing which will ultimately dictate the potential threats here. Suffice it to say a period of hot and stormy wx looks likely Sun-Tue before a more vigorous cold front swings through toward Wed and shunts the heat and moisture south. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 800 PM EDT Fri Jul 12 2024 An upper level vort filament from southern Missouri into west central Ohio will be a focus for isolated showers for a few more hours this evening, but remaining well east of the terminals. A few showers attempted to develop along a lake breeze boundary east of the KSBN vicinity earlier this evening, but loss of peak heating should limit this potential for the remainder of the evening. Northern Indiana should remain between better mid/upper level forcing areas overnight into early Saturday, with clear/partly cloudy skies. Broad low level anticyclone providing light winds, lingering near sfc moisture, and mainly clear skies should allow some shallow fog to form once again Saturday morning. IFR/MVFR vsbys are possible, but confidence remains somewhat low on coverage at the terminals. Fog should dissipate quickly in the 12Z-13Z timeframe on Saturday. A few isolated storms are possible across northern Indiana during the day Saturday but somewhat tempered instability and upstream positioning of forcing should hold off greater thunder chances until after this forecast valid period into Saturday night when richer low level theta-e airmass shifts eastward. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...T AVIATION...Marsili