Area Forecast Discussion
Issued by NWS Northern Indiana
Issued by NWS Northern Indiana
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093 FXUS63 KIWX 030724 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 324 AM EDT Mon Jun 3 2024 .KEY MESSAGES... - Primarily dry today with highs in the 80s. A low chance of isolated storms tonight. - Widespread showers and storms Tuesday night through Wednesday. - Remaining warm through Wednesday before cooler air settles in for the rest of the week. && .DISCUSSION... Issued at 319 AM EDT Mon Jun 3 2024 Fog has developed this morning, primarily north of US 30 and is dense in spots toward the Michigan line. This as high pressure is established over Indiana with ample soil moisture from Saturday and Saturday night`s rainfall. Since the calendar reads, "June", this fog should mix out rather quickly after sunrise. Aloft, a ridge axis is noted over Illinois and Indiana on water vapor. To the west, thunderstorms are decaying as they approach Iowa early this morning associated with an area of low pressure over southern South Dakota. This low lifts northeast through the day as weak troughing over the Northern Plains encounters the aformentioned ridge. HREF guidance indicated 500mb flow not only lifts northeast but weakens through the day. 850-mb flow behaves similarly. Not much to speak of at the surface for a forcing mechanism either. Overall, a very poor case for showers and thunderstorms late today and into the overnight. As a result, leaning on high-resolution guidance, I`ve restored the dry forecast during the day and significantly limited the scope of POPs for tonight, favoring POPs for the Benton Harbor and South Bend areas. This is a significant about-face when compared to earlier forecasts; a byproduct of weak flow and drifting convection. Turning to Tuesday, a pair of short waves ripple into the area working to break down the ridge whose axis is not over the Appalachians. Tuesday likely begins dry (see preceding paragraph) but as afternoon temperatures rise well into the 80s, showers and thunderstorms will dot the area. Instability will be sufficient while shear and lapse rates are lacking. Thus, pulse, non-severe thunderstorms are favored. Showers and thunderstorms become more widespread by Wednesday morning as a deep trough aloft and cold front arrive. Strong cold air advection is in place from Wednesday night through the end of the week. This keeps high temperatures in the low-to-mid 70s. (the in-house blend is still running warm with a 75th percentile forecast Wednesday through Friday.) This trough aloft becomes cut off from the jet stream focused across northern Canada, leaving it to swirl over our heads for an undetermined length of time. Until it kicks east, expect a chance of scattered showers day-to-day and below- normal temperatures. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 132 AM EDT Mon Jun 3 2024 Clear skies, calm wind, and residual boundary layer moisture will support the potential for fog early this morning. Several area sites have already dropped below 1SM and expect visibilities to drop at the terminals soon. While there is reasonable agreement for fog in the guidance (particularly for KFWA) confidence is not high as the moisture is very shallow and visibilities have been variable at other sites so far tonight. Enough support for 1/2SM fog at KFWA but lower confidence at KSBN and will hold with 1SM for now. Otherwise VFR expected the rest of the period. There is a very low chance for a shower or storm at KSBN Monday evening but confidence is far too low to mention in the TAF at this point. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...Brown AVIATION...AGD