Area Forecast Discussion
Issued by NWS Northern Indiana
Issued by NWS Northern Indiana
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942 FXUS63 KIWX 271736 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 136 PM EDT Sat Apr 27 2024 .KEY MESSAGES... - Isolated strong to severe storms with hail and gusty winds this afternoon. - Unseasonably warm and unsettled with periodic rain and storms through much of next week. && .DISCUSSION... Issued at 222 AM EDT Sat Apr 27 2024 Decaying arc of convection advancing newd out of wrn/cntrl IN will be out of ern areas around daybreak. Otherwise broad warm advection continues downstream of sfc cyclone and potent parent wave aloft over nw IA with modest theta-e riding poking into the srn lakes. LLJ weakens through morning and this aftn before some modest strengthening occurs tonight. Adequate low level theta-e ridge remains in place and with substantial diurnal destabilization will lead to redevelopment of showers/storms this aftn within sfc confluence zone broadly pinned through nrn IN/nw OH. This is expected to consolidate in time this evening as it shifts into nw IN/srn MI and where it is likely to persist into early Sun morning before lifting out. Some of these storms this aftn could be strong to severe with marginal hail/gusty winds. Sun expected to be dry and quite warm as heights build through the wrn OH valley in response to next plains bowling ball wrecking havoc out west. Expect widespread 80+ degree temps. Plains low will release on a similar trajectory as the current sys, into sw ON by late Mon as cold front washes out ewd. Still some chance for showers late Sun night/but weakening low level flow/forcing portents little more. Brief/shallow sfc ridge follows Tue before trailing cold front in association with yet another potent nrn plains shortwave stalls out locally early Wed. Thereafter late period muddles considerably owing to stalled frontal zone and continued parade of shortwave disturbances out of the wrn US. Suffice it to say unsettled wx the expectation through DY7 (Fri). Otherwise area will stay on warm side of the flow aloft with unseasonably warm temps persisting through the week before cooling down next weekend. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 1235 PM EDT Sat Apr 27 2024 Strong broad southwesterly low level flow will continue through the remainder of the afternoon with some gusts to 35 knots at times. This southwest low level flow has maintained a moist low level air mass across the area which will allow for weak to moderate surface based instability through early evening. The limiting factor, at least through early evening, for more substantial shower/storm coverage is lack of a clear focusing/forcing mechanism. Expecting a stronger uptick on shower/storm coverage later this evening into the overnight hours as low jet ramps up. Moisture convergence with the low level jet and potential interaction from leftover outflow boundaries from convection may allow for period of regeneration of thunderstorms and some training of storms potential during the overnight hours. Forcing mechanisms in terms of low/mid level moisture convergence looks to maximize from northeast Illinois into northwest Indiana, and thus have hit shower/embedded thunderstorm potential a bit harder for KSBN overnight into early Sunday. Mainly VFR conditions expected this period, although any stronger showers and storms will have temporary vsby/cigs restrictions. Have also included a brief LLWS mention at KFWA to account for northward migration of the low level jet. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...Small Craft Advisory until 8 PM EDT this evening for LMZ043- 046. && $$ DISCUSSION...Roller AVIATION...Marsili