Area Forecast Discussion
Issued by NWS Northern Indiana
Issued by NWS Northern Indiana
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954 FXUS63 KIWX 040737 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 337 AM EDT Tue Jun 4 2024 .KEY MESSAGES... - Hot today followed by scattered showers and thunderstorms tonight. - Showers and thunderstorms linger through Wednesday. - Turning cooler starting Thursday with passing showers at times. && .DISCUSSION... Issued at 335 AM EDT Tue Jun 4 2024 Ridging over the Ohio Valley has steered showers and thunderstorms over Wisconsin and into central Michigan early this morning. Meanwhile, two additional features of note on water vapor: 1) a low spinning over far western Arkansas and 2) a trough digging in over Montana. The Arkansas low is forecast to slowly drift northeast in response to a buckling upper-air pattern. Scattered thunderstorms are forecast to develop over southern Illinois and Indiana in the vicinity of this feature. Locally, forecast soundings are very dry paired with shear of only 20 knots making pop-up convection unlikely today. However, tonight scattered storms drift into the area with now acceptable upper-level support while kinematics remain poor. Overall coverage is uncertain with a variety of solutions among guidance. Therefore, I generally offer "chance" POPs early tonight, increasing prior to dawn Wednesday. These rain chances increase as, what was the Montana trough is now becoming cut off over the Canadian Prairies, and a cold front from the surface low is spreading into the Great Lakes. A marginal risk of severe thunderstorms was introduced by SPC primarily along and east of I-69 Wednesday afternoon and evening ahead of the cold front. Shear is lacking, but instability and lapse rates could prove sufficient for a damaging wind gusts from discrete thunderstorms. Cooler with sporadic showers in the days that follow as the upper- level low swirls over the Great Lakes perhaps through the weekend. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 122 AM EDT Tue Jun 4 2024 Relatively dry low levels and shortwave ridging aloft will support VFR conditions for much of the period. Low level moisture and instability increase by this evening and an approaching trough could generate some isolated storms after 00Z. Confidence in coverage and impact is still low. Best forcing doesn`t arrive until late Tuesday night after the instability has waned. MVFR conditions and isolated storms are possible around/just after 06Z but will hold off on including with this TAF package. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...Brown AVIATION...AGD