Area Forecast Discussion
Issued by NWS Northern Indiana
Issued by NWS Northern Indiana
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165 FXUS63 KIWX 111058 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 658 AM EDT Thu Jul 11 2024 .KEY MESSAGES... - Morning fog dissipates and may allow for a few afternoon showers and thunderstorms that have a chance to linger overnight. - Periodic chances for showers and thunderstorms between Friday and the middle of next week with the best chance for storms occurring during the afternoons. - 90 degree high temperatures are most possible Sunday through Tuesday of next week, dependent on thunderstorm chances. && .DISCUSSION... Issued at 300 AM EDT Thu Jul 11 2024 A relatively dry airmass is in place today with low to mid 60s dew points, but 850 mb dew points around 10C. This still allows for some instability to build in after the morning fog dissipates with 500 to 1500 J/kg of MUCAPE. The kicker shortwave that helped to push the remnants of Beryl eastward only slowly saunters through the Great Lakes region between today and Friday. A lack of upper and low level kinematic support exists limiting shear and this also limits severity to just general thunder mainly south of US-30 this afternoon. Locally heavy rain would be the main threat, which could be exacerbated by the already saturated ground. It is interesting to see models continue the convection tonight without shear and with waning instability perhaps along an outflow boundary and perhaps sustained with the antecedent low level moisture. The ECMWF has an area of warm advection and large scale ascent coupling at times tonight that may be able to sustain it. With the shortwave continuing to saunter through and ongoing showers and storms, Friday, will have to see if sunshine can peak through, but GFS/NAM/ECMWF all create 1500 to 2000 J/kg of MUCAPE, which will allow for more showers and thunderstorms Friday afternoon. DCAPE is still up between 800 and 1200 J/kg indicating wet microbursts could be observed in these storms. There is some signal of more of a moisture axis east of US- 31 on Friday and that seems to be where models are keying into providing PoPs. Highs Wednesday generally spanned the 70s, but with some increased sunshine and some warming in the low levels, temperatures will be able to reach around 80 degrees with a few spots south of US-24 able to reach into the low 80s. This is thunderstorm dependent though. Friday`s highs will also be thunderstorm dependent, but additional warm advection may allow for highs in the low to mid 80s. For Saturday into next week, a ridge over the southwestern CONUS slowly edges eastward into the Central Plains. This pattern will allow Pacific shortwaves to pass near the region through mid week. The first such wave arrives Saturday morning, continues into the day time, and will have some instability to work with, but shear and columnar moisture appear to lacking likely limiting the hazards as a result. A few more of these waves are expected to move through between Sunday and mid week next week providing opportunities for showers and thunderstorms. Through that time frame, an upper low forms across Central Canada and pushes a cold front through by Tuesday or Wednesday of next week. Friday night and Saturday, especially for areas east of IN-15 and north of US-6 have the best chance for a dry period. As mentioned previously, thunderstorms may be around the around area and that could cut into how warm temperatures could get, but Sunday through Tuesday still has the best chance to achieve 90 degrees before temperatures cool off behind the cold front. && .AVIATION /12Z TAFS THROUGH 12Z FRIDAY/... Issued at 658 AM EDT Thu Jul 11 2024 Dense fog is expected to mix out quickly as the sun comes up with return to VFR by 13-14Z (though exact timing is somewhat uncertain). VFR conditions then expected the rest of the period. There is a low chance for storms this afternoon but better forcing and moisture appear to remain southwest of the terminals so will hold dry for now. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...Dense Fog Advisory until 9 AM EDT this morning for INZ005>009- 017-018-025>027-116-216. OH...Dense Fog Advisory until 9 AM EDT this morning for OHZ001-004- 015. MI...Dense Fog Advisory until 9 AM EDT this morning for MIZ078>081. MARINE...None. && $$ DISCUSSION...Roller AVIATION...AGD