####018008884#### FXUS61 KCLE 040212 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 1012 PM EDT Fri May 3 2024 .SYNOPSIS... An active pattern continues as a cold front moves east across the area tonight. Another warm front will lift north on Saturday followed by a cold front on Sunday as the parent low moves northeast into Quebec. High pressure will push in briefly Monday. && .NEAR TERM /THROUGH TODAY/... 10 PM Update Continued to downtrend pops this evening as shower activity diminishes across the area. Kept pops in the chance or lower range with a downtrend from west to east through the overnight. With diurnal stabilization and recent radar trends, opted to remove thunder mention from the forecast for the rest of the night. An isolated rumble isn't out of the question but probabilities are too low for forecast mention at this point. Main forecast challenge overnight will be low end fog potential across the area. Expecting extensive mid/high cloud cover so despite moist boundary layer and lighter winds, radiational cooling should be inadequate for widespread fog development. Some patches cannot be ruled out, especially where rainfall persisted this evening, but again, not confident enough for explicit forecast mention at this time. Original discussion...An active weather pattern will continue through the near term period as multiple boundaries enhanced by upper level shortwaves move across the area. Setting up the big picture, there is a broad upper level trough across the northern contiguous US with an associated low pressure at the surface centered over the north-central US. A cold front associated with this system will move east across the area tonight, bringing another chance of precipitation. Much of the support for shower development is coming from upper level embedded shortwaves which are advecting vorticity across the area. This support coupled with an area of low level convergence should allow for more widespread showers to become established along and east of I71 this evening into the overnight hours. Overall mesoscale conditions, including instability and shear, remain very minimal this afternoon so getting any thunder may be hard but cannot rule out a few rumbles. Primary concern would be heavy rainfall in the strongest showers which may result in nuisance flooding. By Saturday morning, a nose of high pressure pushes over the area and allows for a very brief, although cloudy, period of no precipitation. By Saturday afternoon, another warm front will move north across the area, allowing the chance of showers and isolated thunderstorms to return. These should gradually begin to taper from west to east early Sunday as another cold front approaches, but maintained slight chance for this period. Highs tomorrow will reach into the 70s across western counties, but will remain in the 60s for far NE OH and NW PA. Overnight lows both nights will be in the upper 50s to low 60s. && .SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... A cold front will likely be approaching Toledo early Sunday and will slowly cross the area from west to east by Sunday evening. A slug of deeper moisture and associated showers may still be impacting far eastern OH into northwestern PA early Sunday, though farther west should start the day fairly dry. Additional showers & thunder are expected to develop along the cold front by late morning or early afternoon is it drifts east out of northwestern Ohio and into north central Ohio and then continue east through the afternoon and early evening. Overall, Sunday will feature more clouds than sun with showers and thunder around at times, though a washout type steady rain is unlikely. Not seeing much of a severe weather threat on Sunday, as forcing and shear will be weak. Thermodynamics may support a few stronger storms east/southeast of a Mount Gilead - Parma - Chardon - Edinboro line during the later afternoon hours, with small to perhaps near-severe hail and locally strong winds the main concern if any storms briefly pulse stronger before collapsing due to the lack of stronger shear. Storm motion won't be all that fast so can't rule out a gully-washer or two, though am not expecting enough organization for much of a flooding threat either. High pressure briefly noses in from the north Sunday night into Monday behind the cold front, which should allow us to dry out. As the front begins returning as a warm front late Monday into Monday night rain chances may begin returning from the southwest. Gut feeling is that Monday and Monday night may end up drier than currently forecasted, though given enough model spread and a need to be collaborated, only made modest reductions to the NBM POPs. Highs on Sunday will hinge on how long we can break into some sunshine behind showers exiting to the east in the morning and activity developing and spreading across the area along the cold front during the midday and afternoon timeframe. For now, generally have most of the area in the 70s. Highs generally range from the mid 60s along the lake to the low to mid 70s well-inland on Monday. Lows Sunday and Monday nights will generally settle into the 50s. && .LONG TERM /TUESDAY THROUGH THURSDAY/... The long term will begin with a trough over the northern Plains and a ridge centered over the Southeast, with broad southwest flow in between. The trough will begin shifting towards the Midwest and Great Lakes by Friday. A warm front is expected to lift through on Tuesday, with a cold front expected to cross Thursday into Friday. There will be relatively higher chances for showers and thunder both with the warm frontal passage Tuesday into Tuesday evening, and again Thursday into Friday as the cold approaches and crosses. While we'll be in the open warm sector on Wednesday, activity may develop upstream and spread in later in the day or at night. Severe weather and flooding potential are uncertain, as we will be on the fringes of a moist and unstable with enough flow aloft for organized convection. However, many solutions develop organized clusters of convection well upstream across the Mississippi and Ohio Valleys most days, which would tend to track just to our south and also act to overturn the greater instability before it can advect in. We are not currently "outlooked" for severe weather by the SPC which seems reasonable given the uncertainty and potential limiting factors mentioned above, though experimental machine learning severe weather guidance from Colorado State University does suggest severe potential may bleed into our area (with greater risk just to our southwest) if upstream convection is not too expansive. Temperatures will lean warmer than normal until the cold front crosses. && .AVIATION /00Z Saturday THROUGH Wednesday/... Mainly VFR conditions at the onset of the period, with some light SHRA activity expected to impact terminals over the next six hours east of KTOL/KFDY. Some lowering ceilings possible with some MVFR possible between 06Z and 12Z at some of the terminals. Some lower stratus/FG may advect west off Lake Erie impact KTOL overnight, but confidence too low for explicit IFR mention. SHRA activity will wane after 06Z. Some MVFR ceilings and additional SHRA/potential TSRA moves into the region near the end of the period. Winds will generally be light and variable through the night but will increase out of the south through the day on Saturday. Outlook...Non-VFR likely with periodic showers and thunderstorms through Tuesday. && .MARINE... No marine headlines are expected for the foreseeable future. Southeast winds may briefly become gusty in the nearshore waters off of Pennsylvania late Saturday night into early Sunday morning, though sustained winds likely remain below Small Craft Advisory criteria. A cold front will cross on Sunday. A warm front lifts across the lake Tuesday into Tuesday night, followed by a cold front next Thursday or Friday. A few thunderstorms are possible over the lake Saturday afternoon through Sunday afternoon ahead of an approaching cold front, though greater potential will likely be inland. Additional thunderstorms are possible at times over the lake Tuesday through Friday next week. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. NY...None. MARINE...None. && $$ SYNOPSIS...Campbell NEAR TERM...Campbell/Greenawalt SHORT TERM...Sullivan LONG TERM...Sullivan AVIATION...Greenawalt MARINE...Sullivan