Area Forecast Discussion
Issued by NWS Northern Indiana
Issued by NWS Northern Indiana
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367 FXUS63 KIWX 222159 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 559 PM EDT Wed May 22 2024 .KEY MESSAGES... - Cooler and less humid weather settling in through Friday. - Shower and thunderstorm chances return Friday afternoon and evening with a strong storm possible west of Indiana 15/US 131. - Saturday into early Sunday appears to be dry with additional chances for showers and storms Sunday afternoon into Sunday night. - Lingering showers and storms may impact activities on Memorial Day. && .DISCUSSION... Issued at 235 PM EDT Wed May 22 2024 Drier air continues to filter in behind a pre-frontal trough with the main cold front working across E Illinois. These 2 features should scour out the bulk of the low level moisture and keep stable and quiet conditions in place through Thursday night. Slgt pops were originally in the forecast for this evening in far SE areas to address a weak disturbance moving through SE Missouri towards the Ohio Valley this evening. Showers and storms are active in eastern MO, but models seem to suggest this will weaken with NE extent with loss of heating so consensus has been to remove any mention. Low pressure will track NW of our area, pushing a warm front across the region Friday, with the potential for a few showers and storms along it. A noticeable increase in dewpoints (low to mid 60s) will accompany the front, setting the stage for the potential for a greater coverage of showers and storms as we get into Friday night as a stronger cold front sweeps through the area. While 1000 J/KG or more of SBCAPE will exist ahead of the front, favorable shear lags the front somewhat with the main upper level wave well NW of the area in the Dakotas. In addition, what instability does exist quickly wanes with loss of heating. SPC has the western portions of the area in a Marginal risk which is fine at this point with locally damaging winds and maybe some large hail being the main concerns. Quick shot of drier air arrives behind the front, allowing much of Saturday into early Sunday to be dry. A deeper trough migrates from the Four Corners region Sat morning northeast into the Great Lakes/Ohio Valley for Sunday. The trough becomes negatively tilted with a closed upper low taking shape N IL/S WI Sunday night with the sfc low tracking from Illinois into southern MI. A stronger warm front will surge north Sunday with EC/Canadian bringing mid to maybe upper 60 dewpoints into the area. GFS is the odd ball with low 70 dewpoints across the southern half of the forecast area. The proximity of these features and potential instability by Sunday night could set the stage for showers and storms, some of which could be strong to severe. SPC DY5 outlook has a 15% risk south of US-24 in Indiana with much better severe potential further south. Something we will need to watch not only for the severe concerns, but also the many outdoor activities over the holiday weekend. Lingering clouds and precipitation may be around for many of the ceremonies and parades on Memorial day. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 551 PM EDT Wed May 22 2024 Somewhat cooler and less humid air had spread over northern Indiana at the start of the TAF period. A surface high pressure area will help winds become light by early tonight. Winds will remain light through Thursday with VFR conditions. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...Small Craft Advisory until 8 PM EDT this evening for LMZ043- 046. && $$ DISCUSSION...Skipper AVIATION...Brown