Area Forecast Discussion
Issued by NWS Northern Indiana
Issued by NWS Northern Indiana
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102 FXUS63 KIWX 131731 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 131 PM EDT Mon May 13 2024 .KEY MESSAGES... - Showers and scattered storms arrive late today and persist Tuesday. - Short break in the rain with dry weather Wednesday night and early Thursday followed by more chances for showers and storms through the weekend. - Very warm Sunday with highs around 80, possibly reaching the mid 80s. .DISCUSSION... Issued at 335 AM EDT Mon May 13 2024 Mild but relatively dry low level flow early today at the onset will become slightly more moist later today. Weak upper support and very weak fgen/low level convergence was just enough to trigger/support isolated showers/storms north of the Michigan border. High resolution models/CAMs were having a hard time picking up this activity. Expect the showers and isolated storms will move out of the area before daybreak. An upper level system had moved out of Colorado over the weekend and was over Kansas early this morning. This upper low will drift east ahead of an increasing moist environment. Precipitable water values will rise to around 1.40". Very limited instability and lack of low level shear will greatly limit any severe storm risk. The activity should arrive late today and early tonight and persist through Tuesday. A second upper level system will arrive later in the week and bring additional chances for showers and storms in generally the same environment of high precipitable water values, low CAPE and limited shear. Locally heavy rain is likely at times which will bring rises on rivers and possibly bring a few of the more flashy rivers into action stage or minor flood stage like North Manchester, Portland and Spy Run. The latest OHRFC ensemble river forecasts using the GFS model favor several rivers exceeding the action stage by late Sunday. Otherwise, did raise blend highs for Sunday to around 80 with the potential for highs to reach the mid 80s supported by the EC and GFS. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 123 PM EDT Mon May 13 2024 Steep lapse rates and influx of elevated moisture has resulted in an expanding cu field across mainly western IN back into IL. Handful of cells have managed to gain some strength and even produce some lightning, but weak shear is setting the stage for rather pulsy storms that are difficult to capture in TAFs. KSBN seems to be in the favored path of development, resulting in a continuation of a tempo group for thunder with mainly brief MVFR vsbys. Will need to monitor trends prior to 00Z for possible ramp up to more of a predominate forecast for the activity. Leaving KFWA dry for now through 00Z, but will monitor trends as well. Past 00Z, better coverage should begin to materialize across the area with tempo thunder at KSBN maybe more questionable given loss of heating and potential that any storms this afternoon could reduce instability and limit lightning. No changes for now. Confidence is not overly high on how low cigs will drop late tonight into Tuesday or if showers will last beyond 8 or 9Z. Minor tweaks made but will let later forecasts hone in on things. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...Skipper AVIATION...Fisher