304 FXUS61 KCLE 152229 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 629 PM EDT Tue Oct 15 2019 .SYNOPSIS... High pressure off the coast of the Delmarva will continue to move east of the area overnight. Deepening low pressure will move east into the central Great Lakes Wednesday. The low will force a strong cold front east across the local area tomorrow morning. The low will merge with a low pressure system that will move up the coast and rapidly intensify off the New England coast Thursday. High pressure will build east across the Ohio Valley by the end of the week. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... Just freshened hourly temperatures and our sky grids for the next few hours given latest observed trends and model guidance. The surface cold front should cross our CWA from west to east between about 1 AM and 9 AM EDT tomorrow. Widespread rain showers, some heavy, are expected along and ahead of the front as a warm conveyor belt taps into Gulf of Mexico moisture and undergoes isentropic lift ahead of the front. Elevated instability within the warm conveyor belt should allow isolated thunderstorms to develop along and ahead of the cold front as well. Saw no reason to adjust our POPs and QPF grids at this time, so the rest of the near-term forecast remains valid. Major changes coming in the next 24 hours as large upper level low pressure system dives into the western Great Lakes tonight. This will cause a surface low pressure system to intensify as it deepens and while moving into the central Great Lakes. A strong cold front from the surface low pressure system will sweep east across the local area tomorrow morning. Ample moisture will stream northeast along the frontal boundary and rain will move into the region tonight from west to east. There is the possibility that enough instability will exist to support the mention of a few rumbles of thunder with the cold front and then eventually with the lake effect showers in the northeast. Meanwhile, the upper level low pressure system will extend a negatively tilted trough into the Carolina coast where another surface low pressure system will develop. This system will move rapidly northeast along the East Coast and merge with the Great Lakes low and become an East Coast bomb. This will cause cyclonic flow around the low pressure system by the end of this forecast period over the local area and result in wrap around moisture and the threat for lake effect rain showers. Winds will be increasing ahead of the front out of the south and then as front passes through they should diminish slightly and pick- up again from the west-northwest by Wednesday night. Temperatures will drop off tonight with the passage of the cold front and colder temperatures expected tomorrow in the cold air advection. Overnight lows will settle back into the lower 40s most areas Wednesday night in the cold air mass. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... Lake effect rain showers will continue across NE OH/NW PA into at least Thursday evening. High pressure should take control by Friday morning and continue into Friday night with dry conditions expected. It will be colder in the wake of the cold front with highs in the 50s for both Thursday and Friday. If winds remain light enough there will be some frost Thursday night and again Friday night. Best chances of frost will be across the west Thursday night and the east Friday night. && .LONG TERM /SATURDAY THROUGH TUESDAY/... High pressure will be located at the surface and aloft on Saturday then move east of the area by Sunday morning. This will allow a weak frontal boundary to drift across the region on Sunday with models very uncertain with the amount of moisture along it. For now will go with only slight chances. The stronger storm system will arrive late MOnday afternoon into Monday night with another round of showers and breezy conditions. Lake effect showers in the wake of this storm system on Tuesday will be limited since the overall atmosphere looks to be drier. Warmer Saturday through Monday. Highs over the weekend will be in the 60s to around 70. Slightly warmer with highs mostly in the 70s on MOnday as southwesterly winds increase. && .AVIATION /18Z Tuesday THROUGH Sunday/... Clear skies in place at this time will give way to clouds ahead of a strong cold front. Expecting showers to move into the western portions of the forecast area by this evening and then spread west to east. There is the possibility for a few rumbles of thunder but will leave out of TAFs for now. Visibilities and ceilings will be reduced overnight with the showers and the passage of the front. Expecting winds to increase as well as cold front approaches and then a shift to a west-southwest. Slow improvement in the west during the afternoon but wrap around moisture will return and push clouds back into the region. .OUTLOOK...Non-VFR likely through Thursday and perhaps Friday morning. Lake effect rain showers will affect KERI. Non-VFR Sunday. && .MARINE... Low pressure will move across the central Great Lakes through Wednesday morning with a strong cold front crossing the lake . This will allow winds to shift to the west and northwest in its wake. Speeds will increase significantly with small craft advisories a definite. Slight concern there could be a short duration gale for the eastern half of the lake Wednesday evening into the overnight. One thing against this is that the East Coast low may grab the energy from the Great Lakes region quickly allowing us to avoid or shorten the gale threat to the couple hours of greatest cold advection. Later shifts will need to watch this potential. Winds decrease gradually through Thursday afternoon as high pressure ridges across the lake. Winds should be fairly light Friday into friday night. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...Small Craft Advisory from 8 AM Wednesday to 4 AM EDT Friday for LEZ145>149. Small Craft Advisory from 6 AM Wednesday to 11 AM EDT Thursday for LEZ142>144. && $$ SYNOPSIS...Lombardy NEAR TERM...Jaszka/Lombardy SHORT TERM...MM LONG TERM...MM AVIATION...Lombardy MARINE...MM