Area Forecast Discussion
Issued by NWS Northern Indiana
Issued by NWS Northern Indiana
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733 FXUS63 KIWX 290500 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 100 AM EDT Mon Apr 29 2024 .KEY MESSAGES... - Showers and some thunderstorms will be possible this evening into early Monday and again Monday afternoon with gusty winds and heavy rain being the main threats. - Additional chances for showers and thunderstorms expected during mid to late week period next week. - Warm with highs in the 70s through Friday with 80s also possible on Thursday. && .DISCUSSION... Issued at 254 PM EDT Sun Apr 28 2024 The upper low pressure system across the Upper Mississippi Valley moves northeast into Canada this evening through Monday night. During which time, it`ll push its moisture stream into the forecast area tonight. After an afternoon of mostly dry weather, chances for rain are expected to increase west of IN-31 as it moves east. However, the surface convergence breaks down, instability only achieves 500 J/kg of energy, and precipitation amounts in models lower despite continued push of 1 to 1.5 inch PWATs (1 to 3 SDs above normal) along with 30 kts of effective shear into the area. As such, will look to keep likely PoPs at best. Then, as the moisture stream slides east on Monday, the area with the best chance to see any stronger storms appears to be east of IN-15 and perhaps even as far east as east of I-69. The 7 C/km mid level lapse rates depart the area before the afternoon, but there is some maintenance of the 30 kts of effective shear and 500 J/kg MUCAPE so perhaps a damaging wind gust could be had in the moist environment. Shear appears to have some tendency of both boundary-parallel and -perpendicular flow owing to individual cells and perhaps some linear segments as well. With the MBE vectors going into the inner circle perhaps there could be some back building or slow moving cells to allow for a heavy rain allotment with its convective component. Upper divergence appears to return to southeast after 00z Monday night, which could also support the heavy rain component. The moisture stream slides out of the area for Tuesday allowing for a drier day with sunshine to be observed, especially during the afternoon for eastern areas. Highs still reside in the 70s Monday and Tuesday. Tuesday night into Wednesday morning, a deepening progressive, but slightly negatively tilted area of vorticity swings into the Northern Great Lakes, forcing dissipates as precipitation approaches from the west, so will continue with the dry forecast for Wednesday. Additional ridging continues to build in the southeast CONUS Wednesday through Thursday night continuing the dry streak for the area. It won`t be until Friday that we have another chance to see more rain as a cold front comes through. Timing is in question especially as it pertains to if we can receive a convective component. Next weekend looks cooler with highs in the 60s. Saturday leans drier than Sunday, but Sunday`s chance for rain is on the low side as well. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1257 AM EDT Mon Apr 29 2024 A weak cold front will bring rain and a few embedded thunderstorms to the area today. Rain and thunderstorms can be seen on radar off to the west over Central Illinois. This activity will arrive to KSBN between 09-12Z and to KFWA around 12Z. Scattered light showers are likely to persist through much of the day as the cold front works its way slowly through the area. Ceilings should drop within the next few hours at both terminals, with near MVFR ceilings with the onset of precipitation. Winds will be gusty once again today up to 25 kts. VFR conditions return after 00-03Z by the end of the TAF forecast period. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...Roller AVIATION...Johnson