Snow Trails Snow Report

429 FXUS61 KCLE 010757 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 357 AM EDT Tue Sep 1 2026 .WHAT HAS CHANGED... Forecast remains on track with Advisory level heat indices for northern and western Ohio and severe weather potential for northeastern Ohio and northwestern Pennsylvania. && .KEY MESSAGES... 1) Hot and humid conditions are expected over the next few days with heat indices approaching the low 100s. Little relief is expected overnight with lows in the low to mid 70s. 2) There is potential for multiple rounds of thunderstorms today through Friday bringing with it the potential for severe weather and heavy rain. && .DISCUSSION... KEY MESSAGE 1... The upper level ridge continues to build across the southeastern CONUS allowing for temperatures and humidity to build across the Great Lakes region through mid week. Low level flow will generally be out of the west to southwest into Friday morning that will be the main driver to advect in the warmer and moist air mass from the south. 850mb temperatures will begin to warm today to around 20-22C across the region and persist through Thursday. The warmer side of those temperatures will be across western Ohio with temperatures a few degrees cooler to the east. Regardless, high temperatures are expected to rise into the upper 80s to low 90s today then with more widespread 90s on Wednesday. Dew points will also climb into the upper 60s to low 70s. This will push heat indices up to the upper 90s to low 100s with the higher end out west where the current heat advisory is issued. Additionally, there will be little relief overnight as lows will only drop down into the mid to low 70s. The advisory is currently valid starting this afternoon through Wednesday evening. As with normal summer heat, take precautions when outdoors and limit strenuous activities during peak heating periods. There is some uncertainty with how warm the eastern Ohio and northwestern Pennsylvania will get as rounds of precipitation is expected through Thursday. This will generally keep temperatures "down" a bit with the precipitation and consistent cloud coverage. Though, there maybe enough breaks in the precipitation to allow for temperatures to rise enough for heat indices to reach the upper 90s. Will have to watch how each system develops to see if an eastward expansion of the advisory will be necessary over the next couple of days. For Thursday, a low pressure system will be moving to the north, and will sweep a cold front through the region that day. There should be enough widespread precipitation during the day to keep temperatures down. The upper level ridge will begin to weaken across the region and temperatures will fall to be more seasonal this weekend. KEY MESSAGE 2... Along the upper level ridge, a series of shortwaves are expected to move through the Great Lakes region beginning today through Thursday resulting in rounds of unsettled weather. A warm and moist air mass will be in place across the region with a large surface high to the south. Ample instability of around 2000 MLCAPE will be in place for much of the week with bulk shear vectors of around 35-40 knots. PWATs will also be elevated during this time period at 1.5-2.0", so any thunderstorms that move through will have the threat for heavy rain as well. The first of the shortwaves are expected to move into the region late tonight into early Wednesday morning. There`s plenty of uncertainty regarding the timing and placement of thunderstorms as most CAMs disagree with each other. Any storms should follow the instability gradient which will be situated across northeastern Ohio, though how far west or east it sets up depends on if any precipitation forms today along the lake shore and limits the instability or if there is no development today and it builds east further. Timing is also an issue as some models have the feature moving into northeastern Ohio by 6Z Wednesday morning whereas other are a few hours later. Once the feature gets going up stream, there will be a better idea of the timing and placement as it moves into the region. There should be enough in place though that if storms do form, the would be a damaging wind threat with a secondary threat of large hail. There will be a break in the precipitation after this feature moves late Wednesday morning into the afternoon. Confidence is low, but some thunderstorms are possible Wednesday afternoon into the evening developing off a lake breeze or outflows from the mornings storms. Though the majority should remain dry throughout the day. The next round of thunderstorms are expected later Wednesday night into Thursday morning. A low pressure system will be moving north of the Great Lakes Wednesday night into Thursday and will sweep a cold front through the region on Thursday. The timing of the front is still fairly uncertain as it has shifted over the past few model runs and varies between models as well. If the front slows, then there may be enough time Thursday morning into the mid day to allow for a greater severe weather threat. Though, if it is on the quicker side, then the severe threat may be lower. Will need to monitor how this develops with the convection earlier in the day and timing of the front. For the remainder of Thursday into Friday, showers and thunderstorms are likely though should be more widespread with the front and with the surface high to the south retreating. Additionally, another shortwave is possible late Thursday into Friday that will provide enough support to keep scattered showers and thunderstorms around the region into overnight Friday. The weekend forecast currently is trending dry as Canadian high pressure builds southward over the region. && .AVIATION /06Z Tuesday THROUGH Saturday/... A pronounced ridge remains in place across the region with a few weak waves riding atop the ridge in northwest flow. This will favor continued isolated showers overnight across northern OH and western PA, but exact timing and location are uncertain. For that reason, will leave out of TAFs tonight. Expect widespread high-VFR ceilings and light southerly winds less than 10 knots, becoming southwesterly by morning. Terminals across northeastern OH and northwestern PA can expect gusts 15-20 knots by mid-day Tuesday, with hot and humid conditions aiding development of low-VFR cumulus fields. Outlook...Several rounds of thunderstorms are possible across Northeast Ohio and Northwest Pennsylvania late Tuesday through Wednesday night, with a better chance at showers and storms elsewhere in the area Thursday and Thursday night. Potential exists for an MCS early morning Wednesday, with severe winds and hail possible. && .MARINE... Broad southwest flow is expected to continue as a stationary front parks northeast of Lake Erie, with high pressure entrenched to the south. This pattern will persist through Wednesday before a cold front moves south across the lake on Thursday and Friday. Winds could briefly gust to 20 knots with frontal passage, though small craft advisories are not expected at this time. Unsettled conditions with multiple rounds of thunderstorms are expected through Friday, though exact timing and location of thunderstorms is uncertain at this point. Any thunderstorms that do occur could become severe, with winds > 34 knots and hail > 0.75". && .CLE WATCHES/WARNINGS/ADVISORIES... OH...Heat Advisory from 2 PM this afternoon to 8 PM EDT Wednesday for OHZ003-006>011-017>021-027>031-036-037-047. PA...None. MARINE...None. && $$ DISCUSSION...23 AVIATION...27 MARINE...27