Area Forecast Discussion
Issued by NWS Northern Indiana
Issued by NWS Northern Indiana
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437 FXUS63 KIWX 070729 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 329 AM EDT Sun Jul 7 2024 .KEY MESSAGES... - Leaning dry between today and Monday, although a shower cannot be ruled out west of IN-15 this afternoon. - Chances for showers and thunderstorms increase later Monday into Tuesday, especially west of I-69. - Remnants of TC Beryl could bring rain and storms to parts of the area between later Tuesday and early Thursday with moderate to heavy rain being a possibility. - Temperatures through this forecast period are right around seasonable. Monday looks to be the warmest with highs south of US-24 having a chance to hit 90 degrees. && .DISCUSSION... Issued at 322 AM EDT Sun Jul 7 2024 The day starts off with dry weather with dew points in the low 60s, but the surface high pressure system will saunter off to our east later today and that allows for increases in low level theta-e and wetter surface dew points. Surface dew points will have crept back into the mid 60s by day`s end today as a result of the return flow out of the southwest. The better instability axis is west of IN-15, where 500 to 1000 J/kg of MUCAPE reside. A lack of stronger forcing is expected to keep most shower/storm activity at bay across the area, but cannot completely rule out something west of IN-15 during the afternoon. Will have slight chance PoPs, but these would not be severe with shear limited to less than 30 kts. On Monday, the area is on the eastern side of the trough in the Northern Plains, but much of the forcing is to our west. As such, despite some instability, it`ll be hard to get any obvious convection to set off. Will have slight and low end chance PoPs west of I-69 to indicate the potential for something to form with the highest chance during the overnight hours into early Tuesday. Instability will be similar, if not slightly higher than today with between 500 and 1000 J/kg of MUCAPE, and shear will be marginally conducive to sustaining stronger storms with pockets of 30 kts especially west of IN-15. As we head into the Tuesday through Thursday time period, the remnants of Beryl will be the main focus. Models have trended northward the last couple of runs and PoPs reflect that change. The GFS/NAM appear to be quickest bringing the remnants up this way while the ECMWF/GEM models are on the slower side with this system. As we head into Wednesday, the ECMWF is between the GFS/GEM extremes of carrying the center through the US-24 corridor through Wednesday night. Either way, moisture within the column is increased with sfc dew points sufficiently above 70 degrees and 850 mb dew points above 10C. Shear looks to be available underneath the remnants, but we`ll have to see if a warm sector sets up to see if instability will be available. The 1z NBM run has a 45% chance for 0.5" of QPF over the previous 24 hrs ending 8pm Wednesday through the US-24 corridor. Given the spread on timing, track, and QPF, this would indicate moderate to potentially heavy rain could occur with this. WPC`s ERO was also ticked up to a slight chance for this time period. The remnants of Beryl are currently forecast to move out the area by Thursday, but energy within the trough carrying Beryl out may also cause additional pop storms during the afternoons on Friday and Saturday. Have indicated this with just slight chance PoPs for now given the uncertainty. Temperatures look to stay around normal to slightly above normal from Monday through Friday. The best chance for above normal temperatures look to be on Monday as 90 degrees will be possible south of US-24. Times of clouds and higher dew points likely restricting the upper limits that they could otherwise reach. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 1245 AM EDT Sun Jul 7 2024 High pressure and relatively dry air will remain over the region through the period with VFR conditions expected. There is a very low chance for isolated afternoon storms around KSBN but forcing and available moisture/instability appear far too weak/low to include in the TAF. Winds will also remain light through the period. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...Roller AVIATION...AGD