####018004354#### FXUS63 KIWX 031543 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 1143 AM EDT Fri May 3 2024 .KEY MESSAGES... - Normal to above normal temperatures through the week, with highs in the 70s and low 80s, cooler near Lake Michigan. Lows will be in the 50s and 60s. - There are chances for showers and thunderstorms through the week. Severe weather is not expected at this time. && .DISCUSSION... Issued at 344 AM EDT Fri May 3 2024 Showers and thunderstorms continue this morning associated with a low pressure system centered over the Green Bay/Northern Lake Michigan. The warm front extends down through Holland, MI into NW Ohio, with the best thunderstorm activity along it. To the west, the cold front drops from Green Bay down through Milwaukee and just west of Chicago, IL. Mainly stratiform rain exists ahead of/along the cold front, which will move from west to east across our CWA today. Expect the chances for showers and storms to dwindle eastward accordingly into the late evening before ending overnight. As instability begins to wane, expect thunderstorm activity to be on the downtrend until potentially east of I 69 this afternoon. Even then, surface based CAPE is on the order of around 200-500 J/kg, with the best values south and east of our CWA. Bulk effective shear this afternoon is less than 25 knots, so don't expect much in the way of severe weather. I wouldn't be surprised to see a few pulsey storms with gusty winds/small hail this afternoon if we can get some instability again, but confidence is low. Temperatures look to be a little bit cooler than yesterday, with highs in the 60s and 70s (coldest near Lake MI). Drying out tonight, with lows in the 50s and low 60s. A brief surface high will shift over the CWA tonight into Saturday, eventually getting pinched off between an approaching surface low (cold front) and the exiting low pressure trough to the east. Mid level ridging/subsidence should keep pops limited through Saturday afternoon, when we have the approaching cold front to the west (21- 00z) and the potential convection that develops with daytime heating, lingering LL moisture, and a weak surface low to the SE. I suspect the pops in the east/southeast will be just outside our area until late afternoon/evening when the cold front approaches. Expect weak bulk effective shear (30 knots or less) until the evening, so not expecting too much in the way of severe weather. Again, similar to today, wouldn't be surprised to see a few pulsey storms develop as the forcing approaches from west into a reasonably unstable environment. Otherwise, highs look to be in the 70s. Active weather is expected to continue through next week as our CWA rests on the northwestern periphery of an upper level ridge, making us susceptible to any weaker shortwaves and passing systems. Unfortunately, this also makes the forecast difficult to pin down as it will depend on the strength of the amplifying ridge (also shifting slightly eastward through the week) and how well each wave can capitalize on available moisture/instability. Model guidance is conflicted in terms of specific timing/location of shower activity, so was unable to really add any better detail beyond Sunday's chances. Opted to keep consensus pops largely in the 20-40 percent range through much of next week, with the exception of Tuesday/Wednesday when a stronger system moves into the Great Lakes region. Otherwise, high temperatures will be in the 70s and low 80s, with locations near Lake Michigan slightly cooler (60s, 70s). && .AVIATION /12Z TAFS THROUGH 12Z SATURDAY/... Issued at 1142 AM EDT Fri May 3 2024 Weak cold front making steady progress through the CWA and will clear KFWA by 1pm. Extensive cloud cover this morning has retarded sig heating of otherwise moist prefrontal airmass of which will curtail additional development this aftn. Brief/transitory MVFR based stratocu with fropa otherwise VFR will prevail this period. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...MCD AVIATION...T