Area Forecast Discussion
Issued by NWS Northern Indiana
Issued by NWS Northern Indiana
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313 FXUS63 KIWX 221055 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 655 AM EDT Sun Sep 22 2024 .KEY MESSAGES... - Showers and a few thunderstorms arrive from west to east after sunrise. Rain tapers off tonight. - Hot again this afternoon in northwest Ohio, while those toward the Lake will be in the 70s. - Additional rain arrives Monday night through Tuesday. && .DISCUSSION... Issued at 323 AM EDT Sun Sep 22 2024 Retreating high pressure has left behind dew points in the mid-to- upper 50s early this morning. This is some 10 degrees drier than dew points over western and central Illinois. Thus, approaching rain will have dry air to overcome and POPs have been delayed by a few hours. Time-height cross sections show a stout dry air wedge in the lowest 25k ft, which diminishes by the afternoon (Fort Wayne) with the arrival of improved forcing in the low- levels as a cold front a low pressure center moves through. Thunder cannot be ruled out, especially in the afternoon with improved instability. Rainfall through Sunday night favors Michiana south toward Logansport and Monticello, where rainfall may exceed 0.50". Elsewhere, rainfall will be closer to 0.25". One more note for today: high temperatures will vary from west (near 75) to east (near 85 in northwest Ohio). A break in the rain on Monday as the cold front departs, leaving behind seasonable high temperatures in the low-to-mid 70s. Amid broad troughing over the Central US and a ridge over the Gulf Coast, the next shortwave ripples through Monday night and Tuesday. This favors the highest rainfall totals for central and southern Indiana, but a majority of our forecast area should at least see some rain from this system as well. The late-week forecast is murky, but with some agreement beginning to show with respect to 500mb high anomalies. An anomalously strong ridge is forecast to spread over the Great Lakes late this week while a low takes shape over the southern US. This setup could bring some Atlantic or Gulf moisture into our area paired with above- normal temperatures. The in-house blend appeared overly wet during that time period, so POPs were limited to slight chance (15%) with some inkling that the next forecast run could be dry late-week. && .AVIATION /12Z TAFS THROUGH 12Z MONDAY/... Issued at 656 AM EDT Sun Sep 22 2024 Minor changes to the going forecast for cold front passage later today, mainly to slow down the arrival of fuel-alternate conditions slightly. Still think a period of IFR ceilings will arrive overnight though confidence is slightly lower based on latest guidance. The chance for thunderstorms also remains too low to include in the TAFs. If they occur it would likely be around 21Z for KSBN and 00Z for KFWA but instability/lapse rates appear too meager. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...Beach Hazards Statement from this evening through Monday afternoon for INZ103. OH...None. MI...Beach Hazards Statement from this evening through Monday afternoon for MIZ177-277. MARINE...Small Craft Advisory from 8 PM this evening to 5 PM EDT Monday for LMZ043-046. && $$ DISCUSSION...Brown AVIATION...AGD