416 FXUS61 KCLE 251344 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 944 AM EDT Fri Oct 25 2024 .SYNOPSIS... High pressure slowly exits to the east as low pressure extends a cold front across the region late Friday into Saturday. Another area of high pressure will build overhead later this weekend and persist into next week. && .NEAR TERM /THROUGH SATURDAY/... 9:45 AM Update: Just minor tweaks to POPs, sky, and temperatures to reflect current observations and trends. The forecast is on track. We did see a bit of lightning in our far southwestern counties earlier this morning, but with the activity as a whole on a weakening trend am not expecting more lightning this morning. Previous Discussion... An area of pre-frontal convection continues to push east across northern Indiana early this morning. Recent satellite infrared imagery suggests a gradual weakening trend as the showers and thunderstorms approach the I-75 and I-71 corridors through this morning. Following the morning activity, a lull in precipitation is possible as redevelopment from the pre-frontal convection outflow boundaries will likely initiate just south and southeast of the CWA later this afternoon. Attention will then turn towards an approaching cold front this evening which is expected to sweep southeast through the area. Could see a brief line of rain showers along the front (particularly out east), but not anticipating anything too widespread or heavy. A chilly air mass, characterized by 850 mb temperatures falling around -2 degrees C, will arrive behind the cold front on Saturday. Initially, the mid-level air mass does not appear sufficiently moist to support lake-effect rain showers Saturday morning across Northeast Ohio and Northwest Pennsylvania. However, a lobe of more favorable mid-level moisture is expected to arrive by Saturday afternoon and evening which, coupled with daytime heating, could result in scattered lake-effect rain showers across Northwest Pennsylvania. Slightly above-normal temperatures in the mid-60s are expected today. Temperatures will fall back to below normal in the mid to upper 50s behind the cold front for Saturday. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... The seasonably cool weather will not last long before warmth quickly surges back early next week. The mid/upper trough axis will depart into the eastern Great Lakes and New England Saturday night and Sunday as mid/upper ridging broadens across the Plains and Upper Midwest. This will support increasing upper level confluence across the Great Lakes and Ohio Valley, with associated surface high pressure building over the Ohio Valley by Sunday. Any lingering showers in NW PA will quickly end Saturday night as drier air and strong subsidence build in. This will set up a dry day Sunday with lots of sunshine, but continued cool temperatures as the region remains on the western edge of the cold pool aloft. Lows Saturday night will generally range from the low to mid 30s, except upper 30s near the lakeshore. Some upper 20s are likely in interior NW PA. Highs Sunday will range from the mid to upper 50s, with far NE Ohio and NW PA staying in the low 50s. Decent radiational cooling is again expected Sunday night with lows mainly in the low to mid 30s, except upper 30s near the lakeshore. The big warm up will begin Monday as the mid/upper trough axis lifts out of New England allowing the upstream mid/upper ridge to expand across the eastern CONUS Monday and Monday night, aided by a strong mid/upper trough diving into the western CONUS. In response, the surface high will shift to the East Coast setting up southerly return flow and resultant warm air advection. Mid-level moisture advection and isentropic ascent could generate a few showers along a northward retreating warm front Monday night, but blended guidance suggests that this will largely occur north of the region, so kept dry conditions through Monday night. Highs will warm into the mid to upper 60s in most areas Monday, with upper 50s/low 60s in far NE Ohio and NW PA. Lows Monday night will be much milder, with generally mid 40s to low 50s, coolest in far NE Ohio and NW PA. && .LONG TERM /TUESDAY THROUGH THURSDAY/... The big story of the extended will be much above normal temperatures, averaging 20 degrees above normal. Near record highs are possible Tuesday and Wednesday as the highly amplified mid/upper ridge remains in place across the eastern CONUS ahead of the western CONUS trough progressing into the Plains. This combined with broad surface high pressure offshore of the East Coast will support deep layer southerly flow. Highs will be solidly in the low/mid 70s Tuesday, with highs in the mid/upper 70s Wednesday. The progression of the upstream mid/upper trough is expected to slow Wednesday night and Thursday as it evolves into a cut off low over the northern Plains. This will slow the breakdown of the eastern CONUS ridging allowing the cold front to be slower to move into the region. Blended guidance is trending toward the cold front slowly approaching from the western Great Lakes Thursday, but with uncertainty on when the best upper support arrives, broadbrushed chance PoPs from late Wednesday night through Thursday, with some likely PoPs on Thursday. Would not be surprised to see the front and associated rain chances continue to slow down due to the degree of amplification. Highs Thursday look to remain in the low/mid 70s, and expect gusty southwesterly winds as the pressure gradient increases. && .AVIATION /12Z Friday THROUGH Tuesday/... VFR across the TAF sites this morning with deterioration down to MVFR later this evening and overnight behind a cold front. An area of showers and thunderstorms across Northwest Ohio is beginning to show signs of weakening this morning and should continue to lose steam as it pushes east towards MFD/CLE over the next couple of hours. Elsewhere, scattered, light rain showers are possible across the TAF sites later this morning and afternoon, though vsbys should remain VFR. By later this evening, a cold front will sweep southeast through the area, ushering in a brief period of MVFR ceilings. Winds are generally out of the south to southeast this morning, 5 to 10 knots. Winds will gradually shift more towards the south and southwest through this morning and afternoon, abruptly becoming west to northwest behind a cold front this evening, around 10 knots. Outlook...Non-VFR possible with rain showers and low ceilings Saturday morning. && .MARINE... S winds will increase to 10-20 knots on Lake Erie this morning ahead of a cold front, becoming W and increasing to 15-25 knots this evening as the front crosses the lake. NW winds of 15-25 knots are then expected tonight into Saturday afternoon building waves to 3-5 feet in the central and eastern basins, so Small Craft Advisories are in effect for most of the lake. NW winds will gradually decrease to 10-15 knots Saturday evening and Saturday night, turning SW at 5- 10 knots Sunday. S winds will then increase to 10-15 knots Monday and 15-25 knots by Tuesday, so Small Craft headlines are possible again at that time. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...Small Craft Advisory from 8 PM this evening to 2 PM EDT Saturday for LEZ143-144. Small Craft Advisory from 8 PM this evening to 5 PM EDT Saturday for LEZ145-146. Small Craft Advisory from 8 PM this evening to 2 AM EDT Sunday for LEZ147>149. && $$ SYNOPSIS...Kahn NEAR TERM...Kahn/Sullivan SHORT TERM...Garuckas LONG TERM...Garuckas AVIATION...Kahn MARINE...Garuckas