986 FXUS61 KCLE 261111 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 711 AM EDT Sat Jul 26 2025 .SYNOPSIS... A frontal boundary stretched across the Great Lakes today will sag across the area on Sunday as a weak cold front. The front will dissipate on Monday, allowing hot and humid weather to return to start the week. A stronger cold front is expected to cross Tuesday into Wednesday. && .NEAR TERM /THROUGH TONIGHT/... The main items of interest through tonight include timing of continued intermittent shower and thunderstorm chances... potential for locally heavy rain and isolated severe weather... and warm and humid conditions driving peak heat index values well into the 90s across most of the area this afternoon. At the surface, a warm front stretches from just north of Toledo to near Wooster as of 3 AM and is lifting northeast. A cold front currently extending from the central Great Lakes towards the middle Mississippi Valley will approach from the northwest late tonight. Aloft, a very subtle vort max is located over Northwest Ohio and will move east across northern counties this morning before exiting. The next subtle shortwave is currently nearing Lake Michigan and will pass to our north early to mid afternoon, with influence on the local area limited by subtle height rises aloft. A more well-defined shortwave is lifting into IA and MO early this morning and will ride through the southern Great Lakes this evening into tonight. The lifting front and subtle vort max moving through early this morning are teaming up to allow convection to blossom over Northwest OH and western Lake Erie. This activity will drift east through this morning, with the greatest impacts over the lake and across our northern counties. A period of relatively drier weather is anticipated behind this early round. There is quite a bit of model spread/disagreement regarding not only when and where additional convection develops this afternoon and evening, but also involving how organized and widespread it is. Isolated to scattered convection may start to re-develop early to mid-afternoon as convective temperatures are reached and as a weak shortwave passes just to the north. Confidence is not high, though with a humid and unstable airmass in place do have POPs ramping back up into this afternoon. Will need to watch a lake breeze and perhaps an outflow boundary left by convection to our west (over IN/IL) as potential triggers. The more confident potential for convection appears to be late this afternoon and this evening (after 4 PM) as greater forcing associated with the more well-defined shortwave starts approaching from the west. The general expectation is that this will encourage more widespread and organized convection to our west this afternoon that spreads in this evening, with potential for isolated-scattered convection developing ahead of that. For this main potential round of late- day/evening convection, the uncertainty lies in how much activity occurs during the afternoon ahead of it...which could work over the atmosphere and lead to a drier trend in this evening`s forecast. Another round of convection is strongly suggested by hi-res models overnight tonight into early Sunday morning as the cold front starts approaching from the north, especially from over Lake Erie into nearby northern Ohio and northwestern PA. The forecast has "likely" (60-70% POP) wording at some point this afternoon or tonight across the entire forecast area, with some 80% "categorical" wording off of Lake Erie late tonight, with some attempts at timing the various potential rounds of convection described above. It will not rain all day or night by any stretch, but much of the area will see it at some point. Precipitable water values will be in the 1.80-2.00" range today, with guidance suggesting an increase to 2.00-2.25"+ tonight ahead of the approaching cold front. With skinny instability profiles and deep warm cloud depths, convective cores will be accompanied by impressive/torrential rain rates today and tonight. Any localized training/repeated storms, especially over urban or otherwise prone locations, could lead to isolated flash flooding. May need to pay especially close attention tonight into early Sunday with signs of a moisture rich low- level jet feeding into any convection ahead of the approaching cold front, and with hints that the warm waters of Lake Erie may provide a focus into parts of Northeast OH/Northwest PA. Added heavy rain wording to the forecast for tonight. Assuming we see a window of heating later this morning into the afternoon, 1500-2500 J/KG of MLCAPE is expected to develop with steep low- level lapse rates and modest to moderate DCAPE of 700-1000 J/KG. Poor mid-level lapse rates are a limiting factor. Slightly stronger flow aloft will support 25-30kt of effective deep-layer shear, which supports some convective organization... especially late this afternoon into this evening. The environment appears conducive for isolated damaging winds. The SPC and WPC maintain a Marginal Risk for both severe weather and heavy rain. A locally more organized threat may play out late this afternoon into this evening, though confidence isn`t high given potential for earlier convection to work things over. A locally more organized heavy rain threat may persist through tonight, especially into counties near and east of Lake Erie from northern OH into PA, though confidence is again low. Highs today will reach the mid to upper 80s, with some guidance touching 90 across parts of the area (mainly interior Ohio). Heat index values will reach well into the 90s for most, with low potential (<30%) for isolated peak values near 100. Given uncertainty regarding convective coverage and clouds, held off on heat headlines. However, those with outdoor plans or without AC will need to take precautions for the heat. Lows tonight will again be quite mild, upper 60s to mid 70s. && .SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/... A cold front is expected to be draped from near Toledo and across Lake Erie to start Sunday, and will sag across the area through the afternoon. There likely will be some showers and a few storms ongoing along the front to start the day, especially over Lake Erie and into Northeast OH/Northwest PA. Activity will push inland and begin increasing in coverage and organization through the morning and into the afternoon. Everyone has potential to see a shower or storm on Sunday, though the highest confidence is from a Wyandot to Trumbull County line points south and southeast, where coverage and organization is expected to peak during the afternoon. A drying trend is expected from north to south through the afternoon and into the evening behind the front. Moderate to strong instability ahead of the front, rich low-level moisture and fairly weak flow aloft will support continued potential for locally heavy rain and isolated flash flooding on Sunday, with modest severe potential if any stronger cells can produce a wet microburst or two. Highs on Sunday will range from the mid 80s to near 90, though with slight improvement in the dew points trying to work in from the north through the afternoon. Peak heat index values will again push into the low to mid 90s in OH (staying <90F in much of Northwest PA), below criteria but still hot enough to impact those with sensitivity to heat, outdoor plans, and/or no AC. Lows Sunday night will dip into the upper 60s/lower 70s, with some patchy fog possible in typical lower-lying/rural areas. && .LONG TERM /MONDAY THROUGH FRIDAY/... A hot start to the work-week is expected on Monday, as Sunday`s cold front dissipates and allows for another surge of hot, humid air from the south-southwest. This won`t last too long, with a cold front crossing on Tuesday. The front will only slowly settle to the south through Wednesday night, before stronger high pressure builds in for Thursday and Friday. Have low chances for showers and storms on Monday given no nearby fronts and rising heights aloft. However, will need to watch for a shortwave to push in from the northwest during the afternoon or evening, which could support a round of convection. Low chances persist through Tuesday until the cold front moves through. The forecast now introduces a low chance for showers/storms Wednesday into Wednesday night as the front stalls just to our south and a shortwave rides by. Confidence in the drier forecast increases to end the week. Hot and humid conditions persist for Monday and into Tuesday, before we trend towards normal and even below it during the second half of the week. Heat headlines are possible on Monday and Tuesday may get close as well, especially farther south. && .AVIATION /12Z Saturday THROUGH Wednesday/... Some morning convection will be exiting to the east over the next few hours, followed by a lull in activity through much of the mid day hours. Some spotty SHRA/isolated TSRA possible in the 17-22Z time frame, covered by VCSH in the TAF for locations affected. A shortwave trough aloft gets TSRA back into the fold in the form of 2 hour TEMPO groups after 22Z today for terminals west and later further east. This forcing feature is proving the best way to try and time the later, more organized activity expected today. Outlook...Non-VFR possible through Sunday in scattered showers and thunderstorms with a frontal boundary lingering in the area. Non-VFR possible Tuesday with a cold front passage expected. && .MARINE... With a warm front passing north of Lake Erie this morning, winds will be southerly 5-10kts today and wave heights less than a foot before turning west southwesterly tonight, increasing to 10-15kts by Sunday morning, and wave heights increasing to 1-2ft Cleveland eastward. Back to southwesterly around 10kts for Monday through early Tuesday. A strong cold front comes through Tuesday turning winds onshore around 10kts through Wednesday, increasing to 15kts Thursday into Friday. Wave heights in onshore flow will increase accordingly, likely to the 2-3ft range. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...Sullivan NEAR TERM...Sullivan SHORT TERM...Sullivan LONG TERM...Sullivan AVIATION...26 MARINE...26