734 FXUS61 KCLE 101808 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 208 PM EDT Wed Oct 10 2018 .SYNOPSIS... High pressure centered off the Atlantic coast will continue to bring southerly flow and unseasonably warm temperatures to the region today. A strong cold front will push east across the area late tonight into early Thursday. Seasonably cool high pressure will build east across the Ohio Valley for the end of the week and weekend. && .NEAR TERM /THROUGH THURSDAY/... Scattered showers can be seen on regional radars moving into NW Ohio with another area of showers approaching Central Ohio. No lightning has been observed across the Midwest since sunrise with limited instability. Backed off on the thunderstorm mention with just isolated wording in far western areas this afternoon. Chances will increase tonight ahead of the front with the mid- level dry-slot wrapping in aloft. Previous discussion... The upper level ridge of high pressure which has been dominating our regional weather is slowly losing control of our weather later on today. We will see one more unseasonably warm day across the area this afternoon with highs in the lower to middle 80s. Again, we will be within a few degrees of record highs for today. See climate section below for record high and record high minimums for October 10th. We will also see an increase of high and mid level clouds by this afternoon. A strong trough will be moving through the Upper Midwest Region into the Great Lakes later on today. A cold front will advance in our direction by this evening into tonight. For the most part, showers and storms should stay just to our west for much of the day and start affecting western Ohio by early evening. We expect a broken line of showers and storms along and just ahead of the cold front tonight. At this time, it does not look favorable for any severe weather as this frontal passage will be in the middle of the night with the lack of stronger instability. The cold front should be through the entire area by mid Thursday morning with linger showers possible just behind the front. Our high temperatures for Thursday will happen just after midnight or very early Thursday morning with temperatures slowly falling into the 50s during the on Thursday. It will be blustery and sharply cooler. Northwest winds will be 15 to 25 mph with gusts over 30 mph. Shower chances will end from west to east during the morning and midday time frame. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... A drastic pattern change will usher in a period of below normal temperatures beginning Thursday night. The cold front will be well east of the area by Thursday evening, with strong cold air advection into the region into Friday morning. This should be enough to activate the lake with lake surface-850mb delta T values exceeding 16C with 5kft inversion heights. This will allow for at least some light rain showers across the primary snowbelt Thursday night through Friday. Lows will be in the 40s Thursday night and highs will only reach the low/mid 50s on Friday. The big wrench in the forecast at this point is widespread precip potential Friday night into Saturday as fairly potent mid level shortwave/clipper-type system moves east across the region. The latest GFS/GEM are fairly dry with the system while the latest NAM/ECMWF are fairly wet. Have opted for widespread mid chance pops away from the snowbelt and likely pops across the snowbelt Friday night, with chance pops moving out of the area during the day Saturday. By Saturday afternoon/evening, surface ridging will build northeast from the Mid Mississippi valley into the Mid Atlantic/New England region, which will allow for winds to back southwest, with weak WAA ending lake effect precip. Dry conditions should prevail across most of the area Saturday evening into the overnight. Lows Friday and Saturday night will be in the upper 30s to low 40s, while highs on Saturday will be in the low/mid 50s. && .LONG TERM /SUNDAY THROUGH TUESDAY/... High confidence in below normal temperatures continues through the long term period, however model differences with synoptic features lends to lower confidence in precip potential. A strong shortwave trough will dig southeast across the northern Great Lakes Sunday into southern Quebec by Monday morning. A secondary piece of mid level energy will dig southeast from the central Rockies Sunday into the Ohio valley by Monday night. Surface low pressure is expected to track northeast through the Ohio valley sometime Sunday into Monday. The finer details of precip potential are lost between the handling of the two separate pieces of mid level energy and the interaction of the central CONUS vort max with the Ohio valley surface low. The GEM fills the low Sunday ahead of the northern stream trough's attendant cold front, with little synoptic precip across the local area from the filled low, and little development along the front Sunday evening. The GFS paints a similar solution, but more gradually fills the low and keeps any significant synoptic precip from the low confined to the far southeast part of the area or southeast of the area. The ECMWF is much slower with the surface low, not tracking it into the lower Ohio valley by Sunday night, bringing a significant amount of precip to the entire region along and behind the front Monday into Monday night. The GFS/GEM solutions both have the synoptic front east of the area by Monday morning, with dry conditions outside of any lake effect precip. Given the model differences, have eschewed any likely pops, opting for chance Sunday through Monday evening, with the highest pops late Sunday night through Monday, leaning a little closer to the previous forecast and latest ECMWF solution. Lake effect rain should linger Monday night into Tuesday before the flow back before ridging again moves northeast through the Ohio valley. Highs will be in the mid/upper 50s Sunday, but cooling again behind the front for Monday and Tuesday, with low/mid 50s expected. && .AVIATION /18Z Wednesday THROUGH Monday/... VFR conditions remain across the area with clouds and showers approaching from the south and west. A few showers are possible at TOL/FDY this afternoon and can not rule out an isolated thunderstorm but chances will be low. Showers will increase in coverage ahead of the front tonight, sweeping east across the area in the 00-12Z window. Ceilings will drop to MVFR with the front and linger into Thursday morning before scattering out. A few thunderstorms are possible overnight with best chances at CAK/YNG. Can not rule out a brief window of IFR for an hour or two but confidence was too low to include at this time. Southerly winds will be breezy at times with gusts of 20-25 knots ahead of the front, shifting to the west behind it. OUTLOOK...Non-VFR Thursday through Friday. Non-VFR possible again on Sunday. && .MARINE... Southerly flow will continue across the lake today into this evening before a strong cold front moves east across the lake overnight. Winds will veer westerly behind the front, increasing to 20-25 knots Thursday before subsiding to 15-20 knots Friday and veering northwest Thursday night into Friday. A small craft advisory will be needed for Thursday into at least the first half of Friday. Winds will decrease a bit late Friday into Saturday as high pressure builds across the region. Winds will become southwest Saturday night through Sunday before the next cold front moves across the lake on Monday. && .CLIMATE... Here are the current record temperatures for Wednesday, October 10th. Record High/YearRecord High Minimum/Year Cleveland86/194966/1904 Akron-Canton85/194962/1914 Erie88/194968/1949 Toledo87/201068/1879 Youngstown87/194969/1939 Mansfield85/201064/1919 && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...Griffin NEAR TERM...KEC/Griffin SHORT TERM...Greenawalt LONG TERM...Greenawalt AVIATION...KEC MARINE...Greenawalt CLIMATE...Griffin