851 FXUS61 KCLE 121802 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 202 PM EDT Tue Aug 12 2025 .SYNOPSIS... A trough will move into the Great Lakes Region today pushing a weak cold front south across the area on Wednesday. High pressure will build south out of Canada on Thursday and influence the region through Saturday. && .NEAR TERM /THROUGH WEDNESDAY/... 8:20 AM: Weak lift ahead of a small vort max is combining with a moist and unstable environment to spark a few convective showers (and possibly a rumble of thunder) in the vicinity of Erie, PA early this morning. Added some POPs through 11 AM to account for this. The rest of the forecast is on track. Previous Discussion: The local area resides on the western periphery of high pressure along the East Coast while an upper level trough approaches the Great Lakes region from the northwest. One more hot day is expected today before the heat decreases with a cold front on Wednesday. Highs will be near 90 again today and portions of Northwest and North Central Ohio will experience heat index values in the upper 90s. The forecast challenge through the near term resides around timing of showers and thunderstorms as a slow moving cold front moves southeast across the area through Wednesday. Starting off today, the atmosphere remains dry this morning aside from some low and mid- level moisture seen crossing Lake Erie on satellite imagery. Some of this residual moisture is expected to linger across far NE Ohio and NW Pennsylvania and may be sufficient for a few showers and thunderstorms to develop along the lake breeze early to mid afternoon. HRRR soundings near the lake breeze interface suggest ML CAPE values around 1200 J/kg while areas south of the lake breeze are likely to remain capped. Lowered pops for inland areas and also decreased the coverage slightly. Moisture is expected to increase from the southwest late today but models disagree on the timing. The NAM favors a faster arrival while the RAP/GFS are closer to 00Z or later before we see enough moisture for thunderstorms to increase in coverage across northwest Ohio. For this reason will have slight chance to low chance pops through the afternoon before moisture moving up the Mid-Mississippi Valley arrives this evening and coverage increases. Shortwave energy moving into western Ohio ahead of the deepening trough will provide support for showers and thunderstorms into this evening. A pre-frontal trough reaches NW Ohio this evening while the actual cold front is still back near Chicago. A push of low and mid-level theta-e advection is likely to sustain showers and scattered thunderstorms overnight into NE Ohio. PW values will be near 2 inches and rainfall is expected to be efficient. By Wednesday morning, the cold front will be near Toledo with much of the area still in the warm sector ahead of the front. Showers from overnight may still be ongoing in the south and east before dissipating in the morning. Good coverage of showers and thunderstorms should re-develop along the front and move southeast through the afternoon with ML CAPE values of 1500-2000 J/kg. While most areas will see a quarter to a half inch of rain through Wednesday, pockets of 1-2 inches are possible where thunderstorms occur. A few thunderstorms could produce wind gusts of 40-50 mph with wet microbursts but overall the severe weather threat is expected to be low. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... A broad trough will be over eastern Canada at the start of the short term with one more shortwave moving through the northwest flow aloft. Will hold onto a low slight chance pop on Thursday before high pressure strengthens north of the area. Highs on Thursday settle back into the low 80s with more comfortable humidity with dewpoints in the low 60s. Thursday night will be the coolest of the week with lows in the upper 50s to low 60s. Models are starting to suggest a fairly strong shortwave will cross Lake Erie but with surface high pressure still expecting a mostly dry day. Temperatures on Friday start to creep back up a couple degrees. && .LONG TERM /SATURDAY THROUGH MONDAY/... Upper level ridge amplifies north up the Mississippi Valley towards Chicago over the weekend. Saturday is expected to be a dry day with temperatures trending back above normal. After that we will need to monitor the placement of the ridge and when a shortwave moving through the northwest flow around the ridge could push a frontal boundary south into the area. This could be as early as Sunday or Monday providing the next opportunity for thunderstorms but confidence is below normal with respect to timing. Hot conditions are likely to persist until a front pushes south into the area. && .AVIATION /18Z Tuesday THROUGH Sunday/... Primarily VFR conditions are expected to persist through the TAF window with two windows for showers and thunderstorms that may reduce cigs/vis to MVFR at times. The first window will be diurnally driven showers and storms that have begun to develop along a lake breeze this afternoon. Expect for these showers/storms to continue through late this afternoon/early evening (~22Z). Highest confidence in TSRA impacting a terminal will be at KERI where a TEMPO group for TS impacts is in place from 18-22Z. The next window will be overnight tonight as a cold front approaches the local area from the west. Some uncertainty with the coverage of showers but went ahead and added -SHRA around 05Z at western TAF sites (KTOL/KFDY) before showers move east towards KERI around 09Z. Kept out any TS mention for now given lower confidence, but future TAF packages/amendments may be needed to introduce TS. Generally southerly to southwesterly winds 5-10 knots across inland terminals. Meanwhile, a lake breeze has allowed for westerly to northwesterly winds 8-10 knots to develop a KCLE and KERI. Winds turn light and variable after 00Z tonight before turning generally westerly Wednesday morning. Outlook...Isolated to scattered showers and thunderstorms with non-VFR conditions are forecast through Wednesday evening. && .MARINE... Generally quiet marine conditions will continue through this week as southerly to southwesterly winds 5-10 knots persist over the lake. Winds will become northerly at 8-12 knots behind the cold front Wednesday night/early Thursday. High pressure builds over the lake late this week which will allow for winds to return light and variable. Lake breezes will likely occur again on Friday and Saturday afternoon. There will be favorable conditions for waterspouts as the cold front approaches the lake from the west tonight and Wednesday. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...10 NEAR TERM...10/Sullivan SHORT TERM...10 LONG TERM...10 AVIATION...13 MARINE...13